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BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20230623T130000
DTEND;TZID=Europe/Sofia:20230623T143000
DTSTAMP:20260702T125716
CREATED:20230620T103815Z
LAST-MODIFIED:20230620T103836Z
UID:14584-1687525200-1687530600@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 23 юни 2023 г. (петък) от 13:00 часа в зала 578 на ИМИ – БАН ще се проведе присъствено заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nDistinctness of the “Lifted” Kloosterman Sums over the Prime Field Fp\nще изнесе Любомир Борисов. \n\nАбстракт \n  \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\n\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/copy-%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20230616T130000
DTEND;TZID=Europe/Sofia:20230616T143000
DTSTAMP:20260702T125716
CREATED:20230612T095945Z
LAST-MODIFIED:20230612T095945Z
UID:14552-1686920400-1686925800@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 16 юни 2023 г. (петък) от 13:00 часа ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nPolynomial identities in Novikov algebras\nще изнесе Nurlan Ismailov (Astana IT University and Suleyman Demirel University\, Kaskelen\, Kazakhstan)\n(Joint work with V. Dotsenko and U. Umirbaev). \n\nАбстракт.The talk is devoted to Novikov algebras satisfying nontrivial identities. We show that a Novikov algebra over a field of zero characteristic that satisfies a nontrivial identity satisfies some unexpected “universal” identities\, in particular\, right associator nilpotence\, and right nilpotence of the commutator ideal. This\, in particular\, implies that a Novikov algebra over a field of zero characteristic satisfies a nontrivial identity if and only if it is Lie-solvable. We also establish that any system of identities of Novikov algebras over a field of zero characteristic follows from finitely many of them\, and that the same holds over any field for multilinear Novikov identities. Some analogous simpler statements are also proved for commutative differential algebras. \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Jun 16\, 2023 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-100/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20230609T130000
DTEND;TZID=Europe/Sofia:20230609T143000
DTSTAMP:20260702T125716
CREATED:20230601T070646Z
LAST-MODIFIED:20230601T070646Z
UID:14455-1686315600-1686321000@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 9 юни 2023 г. (петък) от 13:00 часа ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nOld and new aspects of the Poincaré-Birkhoff-Witt theorem\nще изнесе Vladimir Dotsenko (Institute for Advanced Mathematical Research (IRMA)\, University of Strasbourg and CNRS\, France). \n\nАбстракт. The Poincaré-Birkhoff-Witt theorem on universal enveloping algebras of Lie algebras is a fundamental result in many areas of mathematics: from differential geometry and representation theory to homological algebra and deformation quantization. I shall give a short overview of that result and some of its proofs that emerged in about 120 years since Poincaré published a paper about it\, and outline a new proof which perhaps captures its category-theoretic essence in the best way possible. The talk is based on a joint work with Pedro Tamaroff. \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Jun 09\, 2023 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-99/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20230505T130000
DTEND;TZID=Europe/Sofia:20230505T143000
DTSTAMP:20260702T125716
CREATED:20230502T134141Z
LAST-MODIFIED:20230502T134141Z
UID:14286-1683291600-1683297000@math.bas.bg
SUMMARY:Семинар "Алгебра и логика" - встъпителна лекция на проф. Й. Копиц
DESCRIPTION:На 5 май 2023 г. (петък) от 13:00 часа ще се проведе встъпителна академична лекция на \nпроф. Йорг Копиц \nна тема: \nAlgebraic Properties of Transformation Semigroups\nАбстракт. Each semigroup is isomorphic to a semigroup of transformations on a suitable set (Cayley Theorem for semigroups). If we know generating sets of minimal size (rank) of a finitely generating semigroup then we have important information about the algebraic structure of the semigroup itself. For not finitely generated semigroups\, we consider relative generating sets of minimal size modulo a given subset of the semigroup (relative rank). We determine the (relative) rank of several semigroups of transformations. These semigroups were already considered by other authors. \nBy the study of congruences on a semigroup\, we obtain further important information about the structure of a given semigroup\, which are related to its ideals. We discuss the congruence lattice of an infinite transformation semigroup as well of the maximal nilpotent subsemigroups of the Catalan Monoid.\n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \n\n\nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: May 05\, 2023 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-%d0%b2%d1%81%d1%82%d1%8a%d0%bf%d0%b8%d1%82%d0%b5%d0%bb%d0%bd/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20230407T130000
DTEND;TZID=Europe/Sofia:20230407T143000
DTSTAMP:20260702T125716
CREATED:20230403T124532Z
LAST-MODIFIED:20230403T124532Z
UID:14170-1680872400-1680877800@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 7 април 2023 г. (петък) от 13:00 часа ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nExact values of exponential Følner functions and the Coulhon and Saloff-Coste inequality\nще изнесе Богдан Станков (Institut Camille Jordan\, Université Claude Bernard Lyon 1\, France). \n\nАбстракт. For infinite groups\, the Følner criterion states that a group is amenable if and only if the isoperimetric constant of its Cayley graph is 0. In that case\, a more precise description of its isoperimetric profile is given by the Følner function. It depends on the choice of generating set\, but different functions on the same group are asymptotically equivalent. Multiple results have been obtained on Følner functions\, but only up to asymptotic equivalence class. In this talk\, we will consider fixed generating sets and obtain (to our knowledge) the first results (outside of virtually nilpotent groups) on the exact values of Følner functions – on wreath products ℤ ≀ D for a finite group D. We will consider possible applications. In particular\, we’re interested in the connections with the Coulhon and Saloff-Coste inequality. That inequality gives a lower bound on the Følner function. In joint work with Christophe Pittet\, for groups of exponential growth we obtain a description of the optimal multiplicative constant in the Coulhon and Saloff-Coste inequality. We show that the optimal value over all groups of this constant is between 1 and 2. \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Apr 07\, 2023 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-98/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20230224T130000
DTEND;TZID=Europe/Sofia:20230224T143000
DTSTAMP:20260702T125716
CREATED:20230220T100158Z
LAST-MODIFIED:20230220T100158Z
UID:13930-1677243600-1677249000@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 24 февруари 2023 г. (петък) от 13:00 часа ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nReal Hamiltonian forms of affine Toda field theories: spectral aspects\nще изнесе Владимир Герджиков (съвместна работа с Г. Г. Граховски и А. А. Стефанов). \n\nАбстракт. \nThe talk is devoted to real Hamiltonian forms of 2-dimensional Toda field theories related to exceptional simple Lie algebras\, and to the spectral theory of the associated Lax operators. Real Hamiltonian forms are a special type of reductions of Hamiltonian systems\, similar to real forms of semisimple Lie algebras. The real Hamiltonian forms of affine Toda field theories related to exceptional complex untwisted affine Kac – Moody algebras are studied. Along with the associated Lax representations\, we also formulate the relevant Riemann – Hilbert problems and derive the minimal sets of scattering data that uniquely determine the scattering matrices and the potentials of the Lax operators. \nReferences\n[1] V. S. Gerdjikov\, G. G. Grahovski\, A. A. Stefanov. Real Hamiltonian forms of affine Toda field theories: spectral aspects. Theoretical and Mathematical Physics\, 212(2): 1053-1072 (2022); arXiv:2205.03844v1 [nlin.SI] \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Feb 24\, 2023 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-97/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20230217T130000
DTEND;TZID=Europe/Sofia:20230217T143000
DTSTAMP:20260702T125716
CREATED:20230214T123832Z
LAST-MODIFIED:20230214T123832Z
UID:13877-1676638800-1676644200@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 17 февруари 2023 г. (петък) от 13:00 часа ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nInvariant theory for reductive subgroups of reductive groups\nще изнесе Валдемар Цанов (ИМИ-БАН). \n\nАбстракт. Let H ⸦ G be an embedding of connected complex reductive linear algebraic groups. A classical question with several important interpretations is: which irreducible G-modules contain nonzero H-invariant vectors? An approach based on the Geometric Invariant Theory of Hilbert-Mumford was developed in works of Heckman\, Berenstein-Sjamaar\, Belkale-Kumar and Ressayre\, culminating in a description of the generalized Littlewood-Richadson cone – the convex hull of set of the highest weights of the G-modules containing H-invariants. The discrepancy between the convex hull and the actual set of weights presents the so-called saturation problem\, famously solved by Knutson and Tao for diagonal embeddings of GL_n\, and widely open in general. Ressayre’s description of the cone demands extensive calculations even in relatively tame cases\, which makes applications difficult. Further development of the structure theory seems desirable.\nIn this talk\, based on joint works with Seppänen and Staneva\, I will present some structural properties of generalized Littlewood-Richardson cones\, allowing to partition the subgroups of a given G into types according to the properties of the cones. We derive a new numerical invariant of reductive groups\, and use it to show that for “generic” subgroups the cone fills the entire Weyl chamber of G. This greatly reduces the difficulty of the saturation problem and allows it to be solved for some new cases\, e.g. SL_2-subgroups of classical groups. \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Feb 17\, 2023 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-96/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20230210T130000
DTEND;TZID=Europe/Sofia:20230210T143000
DTSTAMP:20260702T125716
CREATED:20230207T091426Z
LAST-MODIFIED:20230207T091426Z
UID:13780-1676034000-1676039400@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 10 февруари 2023 г. (петък) от 13:00 часа ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nA New Approach to the Characteristic Polynomial of a Random Unitary Matrix\nще изнесе Yacine Barhoumi-Andréani (Ruhr-Universität Bochum\, Germany). \n\nАбстракт. The characteristic polynomial of a random (Haar-distributed) unitary matrix is considered as an interesting toy model for the probabilistic study of the Riemann Zeta function. We will recall the history of the topic starting with the Montgommery-Dyson correspondance\, the Keating-Snaith moments conjecture and some recent developments on other functionals. We will then give a conceptual comparison of some of the techniques used in the field and a zoo of results one can achieve\, with a particular focus on a recent technique that allows to rederive all the results in a unified way using symmetric function theory and local Central Limit Theorems. \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Feb 10\, 2023 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-95/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20230113T130000
DTEND;TZID=Europe/Sofia:20230113T143000
DTSTAMP:20260702T125716
CREATED:20230106T122006Z
LAST-MODIFIED:20230106T122006Z
UID:13582-1673614800-1673620200@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 13 януари 2023 г. (петък) от 13:00 часа ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nОтчет за работата по докторантурата на Димитър Добрев на тема “Изкуствен интелект – дефиниция\, реализация и последствия”\nще изнесе Димитър Добрев. \n\nАбстракт. В основата на дисертацията са езиците за описание на светове. Тези езици описват класове от функции като изчислимите функции и някои разширения на този клас. При помощта на език за описание на светове дефинираме ИИ и създаваме програма\, която твърдим\, че удовлетворява тази дефиниция. Тази програма е чисто теоретична\, защото тя е толкова неефективна\, че на практика е неизползваема. Изказваме предположението\, че с подходящ език за описание на светове може да се направи ефективна програма\, която да удовлетвори дефиницията на ИИ и описваме един такъв език. В края на дисертацията се разглеждат някои философски въпроси свързани с последствията от създаването на ИИ. Например задаваме въпроса „Трябва ли технологията ИИ да бъде общодостъпна?“. Отговорът\, който даваме\, е\, че това е опасна технология и не трябва да се разпространява неконтролирано. \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Jan 13\, 2023 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-94/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20221209T130000
DTEND;TZID=Europe/Sofia:20221209T143000
DTSTAMP:20260702T125716
CREATED:20221203T124907Z
LAST-MODIFIED:20221203T124907Z
UID:13375-1670590800-1670596200@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 9 декември 2022 г. (петък) ще се проведе дистанционно заседание на семинара по „Алгебра и логика”\, на което ще бъдат изнесени два доклада. \nОт 13:00 до 14:00 часа доклад на тема: \nAdS/CFT съответствие\, Метрополис-Хастингс алгортъм и GAN невронни мрежи\nще изнесе Веселин Филев. \n\nАбстракт. Ще докладвам за скорошна публикация по конструира-нето на D0/D4 пространство-време. Ще дискутирам значението на това изследване в AdS/CFT съответствието и симулирането на матричния модел на Беркуз-Дъглас. Във втората част на доклада ще дискутирам алгоритъма на Метрополис-Хастингс и ще докладвам възможни приложения на GAN невронни мрежи в симулацията на трудни в изчислително отношение матрични модели. \nОт 14:00 до 14:45 часа доклад на тема: \nHitchin base: Seiberg-Witten differentials and their derivatives\nще изнесе Петър Далаков (АУБ и ИМИ-БАН). \nАбстракт. We consider a variation of Hodge structures of weight 1 and a Seiberg-Witten differential on the Hitchin base and discuss an explicit formula its Gauss-Manin derivative. \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Dec 09\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-93/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20221202T130000
DTEND;TZID=Europe/Sofia:20221202T143000
DTSTAMP:20260702T125716
CREATED:20221130T095341Z
LAST-MODIFIED:20221130T095341Z
UID:13338-1669986000-1669991400@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 2 декември 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nDerivations of upper triangular matrix rings\nvs\nDerivations of upper triangular matrix semirings \nще изнесе Димитринка Владева. \nАбстракт. The motivation for this talk is the problem how to represent a derivation of a matrix ring and of an additively idempotent matrix semiring as a sum of well-known derivations. \nThe results of two of my articles\, published in 2022\, will be compared and we will draw conclusions about the advantages and disadvantages of these results.\nWe begin by considering the nature of derivations of triangular matrices over an additively idempotent semiring R generated by left and right semicentral idempotents. Then we construct a semiring D of these derivations and find a basis of D\, considered as an R-semimodule. The main result of the first article states that an arbitrary derivation of UTMn(R) (the semiring of upper triangular matrices over an additively idempotent semiring R) is a linear combination of a derivations from the basis of R-semimodule D. When R is an associative ring with identity and UTMn(R) is the ring of upper triangular n x n matrices over R we propose a basis of an additive group D of derivations of UTM_n(R) consisting of derivations δ_i such that δ_i(A) = [e_ii\,A]\, where A ∈UTM_n(R) and e_ii are diagonal matrix units for i = 2\, …\, n. The main result states that if D is an arbitrary derivation of the ring UTM_n(R) and A ∈UTM_n(R)\, then there are matrices\, such that the derivative D(A) is a linear combination of the values of derivations δ_i ∈D\, i = 2\, …\, n\, of these matrices with coefficients the entries of the matrix A.\n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Dec 02\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-92/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20221125T130000
DTEND;TZID=Europe/Sofia:20221125T143000
DTSTAMP:20260702T125716
CREATED:20221122T093807Z
LAST-MODIFIED:20221122T093807Z
UID:13319-1669381200-1669386600@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 25 ноември 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nLogic Operators and Quantifiers in Type-Theory of Algorithms\nще изнесе Русанка Луканова (ИМИ – БАН). \n\nАбстракт. I shall introduce an extension of Moschovakis Type-Theory of Algorithms (LR) and its reduction calculus\, by adding logic operators and quantifiers. The LR has two kinds of terms of formulae\, for designating state-independent and state-dependent propositions and predications. The logic operators include conjunction\, disjunction\, implication\, and negation. I extend the formal language of LR by state-dependent quantifiers\, for enhancing the standard quantifiers of predicate logic. I provide an extended reduction calculus of the Type-Theory of Acyclic Algorithms\, for reductions of LR terms to their canonical forms. \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Nov 25\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-91/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20221028T130000
DTEND;TZID=Europe/Sofia:20221028T143000
DTSTAMP:20260702T125716
CREATED:20221025T141256Z
LAST-MODIFIED:20221025T141256Z
UID:13021-1666962000-1666967400@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 28 октомври 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nGabbay Separation for the Duration Calculus\nще изнесе Димитър Гелев (ИМИ – БАН). \n\nАбстракт. Gabbay’s separation theorem about linear temporal logic (LTL) with past has proved to be one of the most useful theoretical results in temporal logic. Is expressive power ultimately affected\, if past constructs are not allowed in the scope of future ones\, or vice versa? Separation implies that it does not\, and also provides a technically convenient normal form for temporal conditions. \nInterval Temporal Logic (ITL) and the Duration Calculus (DC) are interval-based logics. Unlike LTL\, they are based on modalities which allow reference to subintervals of the reference intervals only. Adding the neighbourhood modalities\, which are written <A> and <A-1> in the notation stemming from Allen’s system of interval relations\, enables reference outside the reference interval and this way makes temporal separation relevant. In this talk I propose a DC analogue of a separation theorem for discrete time ITL which I established in a joint work with Ben Moszkowski. \nBoth theorems are analogous to Gabbay’s pioneering result and can be spelled out in similar terms\, but the technical differences are significant. I take the opportunity to not repeat my previous talk on separation for ITL and instead discuss some aspects of the proofs for both the ITL and the DC theorems. Interestingly\, these theorems admit proofs that are based on syntactical transformations of the formulas in the respective logics\, and are therefore compositional and very intuitive. I will focus on the common and the distinct features of the proofs\, and on some side corollaries. \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Oct 28\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-90/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20221021T130000
DTEND;TZID=Europe/Sofia:20221021T143000
DTSTAMP:20260702T125716
CREATED:20221018T214539Z
LAST-MODIFIED:20221018T214539Z
UID:12983-1666357200-1666362600@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 21 октомври 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nRanks and Presentations for Order-Preserving Transformations with One Fixed Point\nще изнесе Jörg Koppitz (съвместна работа със S. Worawiset). \n\nАбстракт. We consider the semigroup (no monoid) of all order-preserving full transformations α on an n-element chain Xn = {1 < 2 …< n}\, where p is the only fixed point in α\, for some given p ∈Xn\, denoted by On\,p. This semigroup is nilpotent. In particular\, the semigroup On\,1 (i.e. p = 1) is already well studied\, since it is the maximal nilpotent subsemigroup of the Catalan monoid. But the semigroup On\,p is still not well studied for p > 1 except of p = n since On\,n is isomorphic to On\,1. We determine the rank of On\,p (it is Cp-1Cn-p – Cp-2Cn-p-1) and give a presentation of On\,p in (Cn-1 – Cn-2) generators and (1 + Cn-1 – Cn-2)(Cn-1 – Cn-2) relations. We illustrate the result for n = 4. \n  \n\n\nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Oct 21\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-89/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20221014T130000
DTEND;TZID=Europe/Sofia:20221014T143000
DTSTAMP:20260702T125716
CREATED:20221010T092028Z
LAST-MODIFIED:20221010T092028Z
UID:12923-1665752400-1665757800@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 14 октомври 2022 г. (петък) от 13:00 ч. в зала 578 ще се проведе хибридно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nСемейства от трилистни накрития на алгебрически криви\nще изнесе Христо Илиев (АУБ и ИМИ – БАН). \n\nАбстракт. Докладът е продължение на предишния ми доклад “Примери на нередуцирани компоненти на Хилбертовата схема от гладки проективни криви с използването на линейчати повърхнини”\, който беше представен на 19-ти август\, 2022г. В сегашния доклад разглеждамe трилистни накрития на гладки алгебрически криви от род γ ≥ 0. В резултат получаваме семейства от криви върху гладки повърхнинни скролове\, които при определени числени ограничения дават компоненти на Хилбертовата схема от криви. \n  \n\n\nСеминарът ще бъде излъчен и онлайн посредством платформата Zoom. Линк към Zoom-стаята на семинара: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Oct 14\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-88/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220923T130000
DTEND;TZID=Europe/Sofia:20220923T143000
DTSTAMP:20260702T125716
CREATED:20220918T210622Z
LAST-MODIFIED:20220918T210622Z
UID:12846-1663938000-1663943400@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 23 септември 2022 г. (петък) от 13:00 ч. в зала 578 ще се проведе присъствено заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nГеометрия и логика в квантовите изчисления\nще изнесе Николай М. Николов (ИЯИЯЕ-БАН). \n\nАбстракт. През 1936г. Гарет Биркхоф и Джон фон Нойман публикуват една от най-общите аксиоматични основи на квантовата теория\, която е известна до днес\, като “Квантова логика” (Annals of Mathematics\, vol. 37 (1936) 823-843). В тази работа те изхождат от орто-модуларна решетка\, която служи като модел на частично нареденото множество на всички квантови събития. Те също откриват връзка с проективната геометрия. Основният случай на геометрии е върху комплексните числа\, но има и възможности за по-общи пръстени с деление\, включително некомутативни. След кратко представяне на тези резултати\, ще обсъдя връзките с крайните геометрии и така наречените “квантови изчисления”. \n\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-87/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220916T140000
DTEND;TZID=Europe/Sofia:20220916T153000
DTSTAMP:20260702T125716
CREATED:20220913T134714Z
LAST-MODIFIED:20220913T134714Z
UID:12843-1663336800-1663342200@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 16 септември 2022 г. (петък) от 14:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nAlmost Prime Ideal and Almost Prime Radical\nще изнесе Alaa Abouhalaka (Çukurova University\, Adana\, Turkey). \n\nАбстракт. In this talk\, we introduce the concept of almost prime (right) ideals in noncommutative rings and provide some equivalent definitions and new results. Also we introduce the concept of almost prime radical of an ideal. \nReferences:\n[1] M.S. Bhatwadekar\, P. K. Sharma\, Unique factorization and birth of almost primes\, Comm. Algebra\, 33(1)\, 43-49\, (2005). \n[2] W.D. Blair\, H. Tsutsui\, Fully prime rings\, Comm. Algebra\, 22(13)\, 5389-5400\, (1994). \n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка:\nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09\n\nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Sep 16\, 2022 02:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-86/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220909T130000
DTEND;TZID=Europe/Sofia:20220909T143000
DTSTAMP:20260702T125716
CREATED:20220902T110036Z
LAST-MODIFIED:20220902T111017Z
UID:12814-1662728400-1662733800@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 9 септември 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nTiming delays in cyber-physical systems\nще изнесе Naijun Zhan (Institute of Software Chinese Academy of Sciences ISCAS\, China). \n\nАбстракт. With the rapid development of feedback control\, sensor techniques and computer control\, time delay has become an essential feature of cyber-physical systems (CPSs)\, underlying both the continuous evolution of physical plants and the discrete transition of computer programs\, which may well annihilate the stability/safety certificate and control performance of CPSs. In the safety-critical context\, automatic verification and synthesis methods addressing time-delay in CPSs should therefore abound. However\, surprisingly\, they do not\, although time-delay has been extensively studied in the literature of mathematics and control theory from a qualitative perspective. In this talk\, we will report our recent efforts to tackle these issues\, including bounded and unbounded verification of delay differential equations and controller synthesis for time-delayed systems\, and discuss remaining challenges and future trends. \n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка:\nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09\n\nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-85/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220819T130000
DTEND;TZID=Europe/Sofia:20220819T143000
DTSTAMP:20260702T125716
CREATED:20220810T083353Z
LAST-MODIFIED:20220810T083353Z
UID:12783-1660914000-1660919400@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 19 август 2022 г. (петък) от 13:00 ч. в зала 578 на ИМИ – БАН ще се проведе хибридно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nExamples of non-reduced components of the Hilbert Scheme of smooth projective curves using ruled surfaces\nще изнесе Христо Илиев (АУБ и ИМИ-БАН). \n\nАбстракт. Let Id\,g\,r be the union of irreducible components of the Hilbert scheme whose general points represent smooth irreducible non-degenerate curves of degree d and genus g in Pr. Using a family of curves found on ruled surfaces over smooth curves of genus γ\, we show that for γ ≥ 7 and g ≥ 6γ+5 the scheme I2g−4γ+1\,g\,g−3γ+1 acquires a non-reduced component D′ such that dim T[X′]D′ = dimD′ + 1 for a general point [X′] ∈ D′. \n\n  \nЛинк към Zoom-стаята на семинара: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Aug 19\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-84/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220729T130000
DTEND;TZID=Europe/Sofia:20220729T143000
DTSTAMP:20260702T125716
CREATED:20220722T183455Z
LAST-MODIFIED:20220722T183455Z
UID:12721-1659099600-1659105000@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 29 юли 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nModal Descriptive Complexity\nще изнесе Петър Илиев (ИФС-БАН и ИМИ-БАН). \n\nАбстракт. The study of the descriptive complexity of a class of structures S relative to a class of formulae F from a logic L revolves around the question: what can we say about the definability of S with formulae from F? For example\, we might want to know whether there is a formula from F defining S or\, if not\, whether there is a countably infinite sequence of F-formulae such that each formula from the sequence defines a subset of S and the union of all these subsets is the whole S. If we have the former situation\, it is natural to ask about the minimal number of variables in any F-formula defining S\, or its minimal length\, or the minimal number of operators like quantifiers\, disjunctions and conjunctions\, and the minimal depth of their nesting. In the latter situation\, we might want to know how (some of) these measures scale with the index of individual formulae. \nIn my talk\, I am going to survey several recent results\, in some of which I have been involved\, coming from the area of the descriptive complexity of classes of Kripke frames (directed graphs) and classes of Kripke models (edge-and vertex-coloured directed graphs) relative to some well-known modal logics. \n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: July 29\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-83/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220701T130000
DTEND;TZID=Europe/Sofia:20220701T143000
DTSTAMP:20260702T125716
CREATED:20220628T173544Z
LAST-MODIFIED:20220628T173544Z
UID:12586-1656680400-1656685800@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 1 юли 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nOn the parity of the coefficients of minimal polynomial of Kloosterman sums over Fp\nще изнесе Любомир Борисов. \n\nАбстракт. Kloosterman sums over finite fields play an important role in “Algebraic Coding Theory” and “Cryptography”. E.g.\, they are related to some families of algebraic codes (Melas\, Kloosterman) and (hyper-)bent functions. Particularly\, the divisibility properties of some quantities connected with the Kloosterman sums\, e.g.\, of minimal polynomial coefficients and power moments\, were also investigated (see\, e.g.\, [1]; [2]). \nIn this talk I shall present some results about the divisibility by 2 of the coefficients of minimal polynomials of the Kloosterman sums.\n\n[1] M. Moisio\, “On certain values of Kloosterman sums”\, IEEE IT\, vol. 55.8 (2009)\, 3563-3564.\n[2] Choi H. T.\, R. Evans\, “Congruences for Sums of Powers of Kloosterman Sums”\, International Journal of Number Theory\, vol. 3(1): 105-117\, 2007.\n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: July 1\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-82/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220624T130000
DTEND;TZID=Europe/Sofia:20220624T143000
DTSTAMP:20260702T125716
CREATED:20220622T092443Z
LAST-MODIFIED:20220622T182836Z
UID:12558-1656075600-1656081000@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 24 юни 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nDependent-Type Theory of Situated Information with Context Assessments\n\nще изнесе Русанка Луканова. \n\nАбстракт. I shall introduce an enriched formal language of information that establishes propositions dependent on situations and types. The types can be basic or complex. Complex propositional types are defined recursively. The language supports structured data of situated information\, which can be partial\, parametric\, and underspecified. Information can be associated with quantitative evaluations depending on situations. The formal terms can integrate propositional types of situated information with statistical and other quantitative evaluations. Structured content integrated with quantitative data facilitates development of new techniques for amalgamating logic representation of situated\, propositional content with numerical data. Numerical data can be provided by techniques from mathematical statistics and probability. Furthermore\, information can be dynamically updated by integration with techniques of machine learning. \n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Jun 24\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-81/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220610T160000
DTEND;TZID=Europe/Sofia:20220610T173000
DTSTAMP:20260702T125716
CREATED:20220603T175441Z
LAST-MODIFIED:20220603T175441Z
UID:12466-1654876800-1654882200@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 10 юни 2022 г. (петък) от 16:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nComputing Eigenvectors of Symmetric Tridiagonals with the Correct Number of Sign Changes\n\nще изнесе Plamen Koev (San José State University\, USA). \n\nАбстракт. The symmetric tridiagonal eigenvector problem has been a central research topic in numerical linear algebra since its inception. Of the myriad of algorithms today\, none is provably optimal and accurate at the same time. “Optimal” means\, a subset of k eigenvectors is computed in O(kn) time. “Accurate” means that the computes eigenvectors are orthogonal and satisfy the typical relative gap error bound. \nIn this talk\, we focus our attention on a neglected oscillating property of the eigenvectors: the i-th eigenvector has exactly i – 1 changes of sign in its entries. Long considered irrelevant\, because the tiny entries of the eigenvectors don’t seem to be of any practical importance\, this property may hold the key to accurate eigenvectors computed in optimal time! \nSuch an approach is not without precedent: the preservation of the mathematical properties of the computed objects has lead to major progress in various computations. \nWe present a new algorithm that computes individual eigenvectors in optimal\, O(n) time\, each guaranteed to have the correct number of sign changes\, and satisfying the conventional relative gap error bound. The numerical experiments in this work in progress look promising in that the computed eigenvectors seem to also be orthogonal. \n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Jun 10\, 2022 04:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-80/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220520T160000
DTEND;TZID=Europe/Sofia:20220520T173000
DTSTAMP:20260702T125716
CREATED:20220516T084953Z
LAST-MODIFIED:20220516T084953Z
UID:12365-1653062400-1653067800@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 20 май 2022 г. (петък) от 16:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nBootstrap percolation: merging operations for polytopes\n\nще изнесе Ivailo Hartarsky (Université Paris-Dauhpine\, PSL\, France\,\nvisiting scholar at Instituto de Matemática Pura e Aplicada\, Rio de Janeiro\, Brazil). \n\nАбстракт. Bootstrap percolation is a group of statistical physics models intensively studied since the 1970s in mathematics\, physics\, computer science\, as well as social sciences. They are cellular automata generalising the following paradigmatic example. Arbitrarily declare some sites of Z^2 initially infected. Iteratively\, at each discrete-time round\, additionally infect each site with at least 2 infected neighbours. \nThe last decade has seen the accomplishment of a full classification of all such models into `universality classes’\, depending on their behavior when few sites are initially infected. In this talk\, we will overview universality results\, mostly in two dimensions. We will focus particularly on a key aspect of the proof of the lower bounds for the `critical’ class. Thаt is a natural polygon merging procedure to be discussed in detail. \nNo prerequisites (particularly in probability) are required\, as we will exclusively focus on the combinatorial side of the subject\, which is completely elementary. \n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: May 20\, 2022 04:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-79/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220513T130000
DTEND;TZID=Europe/Sofia:20220513T143000
DTSTAMP:20260702T125716
CREATED:20220506T154341Z
LAST-MODIFIED:20220506T154341Z
UID:12331-1652446800-1652452200@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 13 май 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nA counterexample to the modular isomorphism problem\n\nще изнесе Diego García-Lucas (Universidad de Murcia\, Spain). \n\nАбстракт. The modular isomorphism problem asks whether the isomorphism type of the modular group algebra of a p-group G over a field of characteristic p determines the isomorphism type of G. It was explicitly mentioned in a survey by Richard Brauer in 1963\, and was the only classical version of the isomorphism problem for group rings which had resisted a solution\, though it received considerable attention. Several partial positive solutions were obtained imposing very strong conditions on the group G\, for instance the one of being metacyclic. \nIn a joint work with Leo Margolis and Ángel del Río\, we solve the modular isomorphism problem in the negative by exhibiting a series of pairs of non-isomorphic 2-groups with isomorphic modular group algebras over every field of characteristic 2. These groups are two-generated with cyclic derived subgroup. We will also discuss the (lack of) possibility of obtaining\, in a naive way\, analogues to the counterexamples for p > 2 verifying this condition.\n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: May 13\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-78/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220429T160000
DTEND;TZID=Europe/Sofia:20220429T173000
DTSTAMP:20260702T125716
CREATED:20220423T113407Z
LAST-MODIFIED:20220423T113407Z
UID:12226-1651248000-1651253400@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 29 април 2022 г. (петък) от 16:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nImages of multilinear polynomials on upper triangular matrices\n\nще изнесе Thiago Castilho de Mello (Universidade Federal de São Paulo\, Brazil). \n\nРезюме. Let f(x1\, …\, xm) be a polynomial in noncommutative variables over an infinite field K. If A is a K-algebra\, it defines in a natural way a map Am → A. If the polynomial f is multilinear\, the famous Lvov-Kaplansky conjecture asks whether the image of a multilinear polynomial on a matrix algebra is a vector subspace. Solutions to this problem are known only for n = 2 or m = 2 with partial results for m = 3 and n = 3. \nIn this talk\, we survey these results and discuss possible variations for this problem in the associative and nonassociative settings. \nIn particular\, we discuss a joint work with I. Gargate about images of multilinear polynomials on upper triangular matrices. \n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Apr 29\, 2022 04:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-77/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220415T130000
DTEND;TZID=Europe/Sofia:20220415T143000
DTSTAMP:20260702T125716
CREATED:20220411T183752Z
LAST-MODIFIED:20220411T184049Z
UID:12144-1650027600-1650033000@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 15 април 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nQuantisation of free associative dynamical systems.\nBi-quantum structure of the stationary KdV hierarchy.\nNon-deformation quantisation of the Volterra hierarchy\n\nще изнесе Alexander V. Mikhailov (University of Leeds\, UK). \n\nРезюме. Traditional quantisation theories start with classical Hamiltonian systems with variables taking values in commutative algebras and then study their non-commutative deformations\, such that the commutators of observables tend to the corresponding Poisson brackets as the (Planck) constant of deformation goes to zero. I am proposing to depart from dynamical systems defined on a free associative algebra A. In this approach the quantisation problem is reduced to the problem of finding of a two-sided ideal J ⸦ A satisfying two conditions: the ideal J has to be invariant with respect to the dynamics of the system and to define a complete set of commutation relations in the quotient algebras A_J = A / J. \nTo illustrate this approach I’ll consider the quantisation problem for N-th Novikov equations and the corresponding finite KdV hierarchy. I will show that stationary KdV equations and Novikov’s equations admit two compatible quantisations\, i.e. two distinct commutation relations between the variables\, such that a linear combination of the corresponding commutators is also a valid quantisation rule leading to the Heisenberg form of quantum equations. The picture is very similar to the bi-Hamiltonian structure in the case of classical integrable equations. \nAlso\, I am going to discuss quantisation of the Bogoyavlensky family of integrable systems. In particular\, I will show that odd degree symmetries of the Volterra chain admit two quantisations\, one of them is a well-known quantisation of the Volterra chain\, and another one is new and not a deformation quantisation. \nThe talk is partially based on: \nAVM\, Quantisation ideals of nonabelian integrable systems\, arXiv:2009.01838\, 2020 (Published in Russ. Math. Surv. v.75:5\, pp 199-200\, 2020) \nV. M. Buchstaber and AVM\, KdV hierarchies and quantum Novikov’s equations\, arXiv:2109.06357v2\, 2021. \n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Apr 15\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-76/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220401T130000
DTEND;TZID=Europe/Sofia:20220401T143000
DTSTAMP:20260702T125716
CREATED:20220328T054737Z
LAST-MODIFIED:20220328T054737Z
UID:12103-1648818000-1648823400@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 1 април 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nAutomorphisms of simple quotients of the Poisson and universal enveloping algebras of sl_2\nще изнесе Altyngul Naurazbekova (L. N. Gumilyov Eurasian National University\, Nur-Sultan\, Kazakhstan). \nРезюме. Let P(sl_2(K)) be the Poisson enveloping algebra of the Lie algebra sl_2(K) over an algebraically closed field K of characteristic zero. U. Umirbaev\, V. Zhelyabin proved that the quotient algebras P(sl_2(K))/(C_P – λ)\, where C_P is the standard Casimir element of sl_2(K) in P(sl_2(K)) and 0 ≠ λ ∈K\, are simple. Using a result by L. Makar-Limanov on groups of automorphisms of a class of surfaces\, we describe generators of the automorphism group of P(sl_2(K))/(C_P – λ) and represent this group as an amalgamated product of its subgroups. Moreover\, using similar results by J. Dixmier and O. Fleury for the quotient algebras U(sl_2(K))/(C_U – λ)\, where C_U is the standard Casimir element of sl_2(K) in the universal enveloping algebra U(sl_2(K))\, we prove that the automorphism groups of P(sl_2(K))/(C_P – λ) and U(sl_2(K))/(C_U – λ) are isomorphic.This is a joint work with professor U. Umirbaev. \n\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Apr 1\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-75/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220325T130000
DTEND;TZID=Europe/Sofia:20220325T143000
DTSTAMP:20260702T125716
CREATED:20220321T225239Z
LAST-MODIFIED:20220321T225239Z
UID:12068-1648213200-1648218600@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 25 март 2022 г. (петък) от 13:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nAn Application of Separation in Discrete Time Interval Temporal Logic to Branching Time\nще изнесе Димитър Гелев (ИМИ – БАН). \nРезюме. In this talk we make an application of our separation theorem for discrete time Interval Temporal Logic (ITL) to the study of Interval-based Computation Tree Logic (ICTL*). We prove that the expressibility of the expanding modalities and\, most importantly\, propositional quantification\, carry over from linear time ITL to the branching time system of ICTL*. The relevance of this follows from the fact that point-based propositionally quantified CTL* (QCTL*) is the established intermediate language for temporal logics of agency as propositional quantification enables expressing the existence of strategies with given temporal properties. By moving to ITL we move a step further\, using the expressibility of propositional quantification in the logic\, which is markedly more expressive than point-based CTL* and facilitates the compositionality of specifications.\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Mar 25\, 2022 01:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-74/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20220318T160000
DTEND;TZID=Europe/Sofia:20220318T173000
DTSTAMP:20260702T125717
CREATED:20220314T203522Z
LAST-MODIFIED:20220314T203752Z
UID:12050-1647619200-1647624600@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 18 март 2022 г. (петък) от 16:00 ч. ще се проведе дистанционно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nAbsorbing ideal structures of commutative rings\nще изнесе Ece Yetkin Celikel (Hasan Kalyoncu University\, Turkey). \nРезюме. Let R be a commutative ring with nonzero identity. As generalizations of prime ideals\, the absorbing ideals were first defined and studied by A. Badawi in 2007. A proper ideal I of R is said to be 2-absorbing if whenever a\, b\, c ∈ R with abc ∈ I\, then either ab ∈ I or ac ∈ I or bc ∈ I. After this date\, many researches have been done to introduce various extensions of this concept.\nIn this talk\, we present some absorbing ideals of this class of ideals in general aspect with a number of examples\, and also we give many characterizations for some particular rings such as quasi-local rings\, Dedekind domains\, fields in terms of absorbing ideals.\n  \nСеминарът ще се проведе посредством платформата Zoom и всеки желаещ може да се присъедини като последва линка: \nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nTopic: Онлайн семинар на секция “Алгебра и логика”\nTime: Mar 18\, 2022 04:00 PM Sofia\nMeeting ID: 851 3737 5021\nPasscode: 035647 \nОт секция „Алгебра и логика” на ИМИ – БАН\nhttp://www.math.bas.bg/algebra/seminarAiL/\n============================== =====================
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%b0%d0%bb%d0%b3%d0%b5%d0%b1%d1%80%d0%b0-%d0%b8-%d0%bb%d0%be%d0%b3%d0%b8%d0%ba%d0%b0-73/
LOCATION:Zoom
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%A1%D0%B5%D0%BA%D1%86%D0%B8%D1%8F%20%D0%90%D0%BB%D0%B3%D0%B5%D0%B1%D1%80%D0%B0%20%D0%B8%20%D0%BB%D0%BE%D0%B3%D0%B8%D0%BA%D0%B0":MAILTO:algebra_logic_seminar@math.bas.bg
END:VEVENT
END:VCALENDAR