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BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231010T140000
DTEND;TZID=Europe/Sofia:20231010T153000
DTSTAMP:20260614T205444
CREATED:20231010T072649Z
LAST-MODIFIED:20231010T073059Z
UID:15105-1696946400-1696951800@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:На 10.10.2023 г. (вторник) от 14:00 часа в зала 403 на ИМИ\nще се състои първата сбирка на семинара на МЦМН за 2023/2024 г. \nДоклад на тема: \nAbout a generalisation of Sylvester’s law of inertia\nще изнесе Stéphanie Cupit-Foutou (Ruhr Universitat\, Bohum). \nhttps://icms.bg/about-a-generalisation-of-sylvesters-law-of-inertia-talk-by-stephanie-cupit-foutou/ \nРезюме. Sylvester’s law of inertia can be formulated in terms of group actions when considering real linear groups acting on real quadratic forms by base change. After reviewing this celebrated result from this perspective\, I will give a generalisation of it in the setting of so-called spherical varieties (a class of complex varieties including flag varieties\, toric varieties\, symmetric spaces\, etc.). This is a joint work with D. Timashev
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-3/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231017T140000
DTEND;TZID=Europe/Sofia:20231017T153000
DTSTAMP:20260614T205444
CREATED:20231010T074351Z
LAST-MODIFIED:20231010T074351Z
UID:15108-1697551200-1697556600@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 17.10.2023 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Михаил Школников\, ИМИ – БАН \nДоклад: Tropical structures in sandpile model \nРезюме: The sandpile model is a cellular automaton that can be defined on any graph. Though it has appeared independently in a variety of contexts\, it attracted tremendous attention from the wide scientific community when its instance on a large domain of the square lattice was put forward as the simplest rigorous example of self-organized criticality. Such phenomena\, real-life examples of which are earthquakes\, solar flares\, or neuronal avalanches\, could be vaguely described as being between order and chaos\, demonstrating power laws without being finely tuned\, and transcending the scale. Tropical geometry\, on the other hand\, is a field of pure mathematics often presented as a combinatorial version of algebraic geometry. I will tell how tropical curves arise in the scaling limit of the sandpile model in the vicinity of the maximal stable state and explain two major consequences inspired by this fact. The first one is that there is a continuous model for self-organized criticality\, the only known model of a kind\, defined in the realm of tropical geometry. The second is that the totality of recurrent states in the original sandpile model\, the sandpile group\, approximates a continuous group\, a tropical Abelian variety\, which is functorial with respect to inclusions of domains\, allowing to compute its scaling limit as a space of circle-valued harmonic functions on the whole lattice. \n\nTropical structures in sandpile model\, talk by Mikhail Shkolnikov\, IMI-BAS \n\n 
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-4/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231030T140000
DTEND;TZID=Europe/Sofia:20231030T153000
DTSTAMP:20260614T205444
CREATED:20231010T080439Z
LAST-MODIFIED:20231010T080439Z
UID:15119-1698674400-1698679800@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 30.10.2023 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Петър Далаков\, ИМИ – БАН \nКурс: Introduction to Projective Structures and Opers \nРезюме: A complex projective structure on a Riemann surface is determined by an atlas\, whose transition functions are Moebius (fractional-linear) transformations. There are multiple   descriptions of these structures: as certain flat PGL_2-bundles\, as Sturm-Liouville operators\, as holomorphic connections on the (first) jet bundle of the dual of a theta-characteristic\, etc. This mini-course is an introduction to the fundamentals of projective structures\, accessible to students and non-specialists. We will also explore links to some classical geometric objects (such as quadratic differentials and Schwarzian derivatives)\, as well as some generalisations (G-opers) introduced by Beilinson and Drinfeld. \n\nIntroduction to Projective Structures and Opers\, course by Peter Dalakov \n\n  \n 
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-6/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231031T140000
DTEND;TZID=Europe/Sofia:20231031T153000
DTSTAMP:20260614T205444
CREATED:20231010T080721Z
LAST-MODIFIED:20231010T080721Z
UID:15124-1698760800-1698766200@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 31.10.2023 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Петър Далаков\, ИМИ – БАН \nКурс: Introduction to Projective Structures and Opers \nРезюме: A complex projective structure on a Riemann surface is determined by an atlas\, whose transition functions are Moebius (fractional-linear) transformations. There are multiple   descriptions of these structures: as certain flat PGL_2-bundles\, as Sturm-Liouville operators\, as holomorphic connections on the (first) jet bundle of the dual of a theta-characteristic\, etc. This mini-course is an introduction to the fundamentals of projective structures\, accessible to students and non-specialists. We will also explore links to some classical geometric objects (such as quadratic differentials and Schwarzian derivatives)\, as well as some generalisations (G-opers) introduced by Beilinson and Drinfeld. \n\nIntroduction to Projective Structures and Opers\, course by Peter Dalakov \n\n  \n 
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-7/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231102T140000
DTEND;TZID=Europe/Sofia:20231102T153000
DTSTAMP:20260614T205444
CREATED:20231010T081045Z
LAST-MODIFIED:20231010T081045Z
UID:15128-1698933600-1698939000@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 02.11.2023 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Петър Далаков\, ИМИ – БАН \nКурс: Introduction to Projective Structures and Opers \nРезюме: A complex projective structure on a Riemann surface is determined by an atlas\, whose transition functions are Moebius (fractional-linear) transformations. There are multiple   descriptions of these structures: as certain flat PGL_2-bundles\, as Sturm-Liouville operators\, as holomorphic connections on the (first) jet bundle of the dual of a theta-characteristic\, etc. This mini-course is an introduction to the fundamentals of projective structures\, accessible to students and non-specialists. We will also explore links to some classical geometric objects (such as quadratic differentials and Schwarzian derivatives)\, as well as some generalisations (G-opers) introduced by Beilinson and Drinfeld. \n\nIntroduction to Projective Structures and Opers\, course by Peter Dalakov \n\n  \n 
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-8/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231106T140000
DTEND;TZID=Europe/Sofia:20231106T153000
DTSTAMP:20260614T205444
CREATED:20231010T081237Z
LAST-MODIFIED:20231010T081237Z
UID:15132-1699279200-1699284600@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 06.11.2023 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Петър Далаков\, ИМИ – БАН \nКурс: Introduction to Projective Structures and Opers \nРезюме: A complex projective structure on a Riemann surface is determined by an atlas\, whose transition functions are Moebius (fractional-linear) transformations. There are multiple   descriptions of these structures: as certain flat PGL_2-bundles\, as Sturm-Liouville operators\, as holomorphic connections on the (first) jet bundle of the dual of a theta-characteristic\, etc. This mini-course is an introduction to the fundamentals of projective structures\, accessible to students and non-specialists. We will also explore links to some classical geometric objects (such as quadratic differentials and Schwarzian derivatives)\, as well as some generalisations (G-opers) introduced by Beilinson and Drinfeld. \n\nIntroduction to Projective Structures and Opers\, course by Peter Dalakov \n\n  \n 
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-9/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231114T140000
DTEND;TZID=Europe/Sofia:20231114T153000
DTSTAMP:20260614T205444
CREATED:20231010T083449Z
LAST-MODIFIED:20231010T090357Z
UID:15136-1699970400-1699975800@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 14.11.2023 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Валдемар Цанов\, ИМИ – БАН \nКурс: Invariant theory\, homogeneous projective varieties\, and momentum maps \nРезюме: Let \(f:K\to U(V)\) be a unitary representation of a compact Lie group \(K\) with Lie algebra \(\mathfrak k\). This series of talks will be devoted to some recent developments based on relations between the following three classical notions. \n\nThe ring of -invariant polynomials \(\mathbb C[V]^K\) is finitely generated by homogeneous elements\, by a theorem of Hilbert\, but the proof is notoriously nonconstructive. The degrees of a minimal set of generators are canonically determined by \(f\)\, and will be the focus of the discussion.\nThe \(K\)-equivariant momentum map \(\mu:\mathbb P(V)\to \mathfrak k^*\) associated to the Fubini-Study form encodes in its image properties of the invariant ring \(\mathbb C[V]^K\) and the \(K\)-module structure of the entire polynomial ring \(\mathbb C[V]\)\, due to theorems of Mumford and Brion. While many general properties of momentum images have been established\, explicit descriptions remain unknown in many cases south for in physics and quantum information theory.\nProjective geometry of complex \(K\)-orbits in \(\mathbb P(V)\); their fundamental forms\, osculating varieties and secant varieties.\n\nGeneral relations between the first two topics are well established\, even in a more general context. There are also well known relations between invariant theory and projective geometry\, but secant varieties have only recently been brought to the discussion and are subject of current interest. \nAfter introducing the basic notions\, I will derive some properties of momentum images related to fundamental forms and osculating varieties\, as well as a lower bound on the minimal positive degree of a homogeneous invariant\, derived using secant varieties. At the end I will present a class of homogeneous projective varieties\, characterized by a special property of their secant varieties\, where the relations between the above three concepts take a particularly pristine form. \n\nInvariant theory\, homogeneous projective varieties\, and momentum maps\, course by Valdemar Tsanov \n\n 
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-10/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231115T160000
DTEND;TZID=Europe/Sofia:20231115T173000
DTSTAMP:20260614T205444
CREATED:20231110T165607Z
LAST-MODIFIED:20231110T165607Z
UID:15402-1700064000-1700069400@math.bas.bg
SUMMARY:Семинар по геометрия на МЦМН
DESCRIPTION:Следващата сбирка на Семинара по геометрия на МЦМН\nще се проведе в сряда\, 15 ноември 2023 г. от 16:00 ч. в зала 403 и онлайн в Zoom:\n\nTopics in non-archimedean analytic geometry (I)\, \nby Jiachang Xu – International Center for Mathematical Sciences (ICMS – Sofia)\n\nZoom link:\n\nhttps://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bf%d0%be-%d0%b3%d0%b5%d0%be%d0%bc%d0%b5%d1%82%d1%80%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-2/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%98%D0%BD%D1%81%D1%82%D0%B8%D1%82%D1%83%D1%82%20%D0%BF%D0%BE%20%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20%D0%B8%20%D0%B8%D0%BD%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20-%20%D0%91%D0%90%D0%9D":MAILTO:office@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231116T140000
DTEND;TZID=Europe/Sofia:20231116T153000
DTSTAMP:20260614T205444
CREATED:20231010T091536Z
LAST-MODIFIED:20231010T091536Z
UID:15145-1700143200-1700148600@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 16.11.2023 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Валдемар Цанов\, ИМИ – БАН \nКурс: Invariant theory\, homogeneous projective varieties\, and momentum maps \nРезюме: Let \(f:K\to U(V)\) be a unitary representation of a compact Lie group \(K\) with Lie algebra \(\mathfrak k\). This series of talks will be devoted to some recent developments based on relations between the following three classical notions. \n\nThe ring of -invariant polynomials \(\mathbb C[V]^K\) is finitely generated by homogeneous elements\, by a theorem of Hilbert\, but the proof is notoriously nonconstructive. The degrees of a minimal set of generators are canonically determined by \(f\)\, and will be the focus of the discussion.\nThe \(K\)-equivariant momentum map \(\mu:\mathbb P(V)\to \mathfrak k^*\) associated to the Fubini-Study form encodes in its image properties of the invariant ring \(\mathbb C[V]^K\) and the \(K\)-module structure of the entire polynomial ring \(\mathbb C[V]\)\, due to theorems of Mumford and Brion. While many general properties of momentum images have been established\, explicit descriptions remain unknown in many cases south for in physics and quantum information theory.\nProjective geometry of complex \(K\)-orbits in \(\mathbb P(V)\); their fundamental forms\, osculating varieties and secant varieties.\n\nGeneral relations between the first two topics are well established\, even in a more general context. There are also well known relations between invariant theory and projective geometry\, but secant varieties have only recently been brought to the discussion and are subject of current interest. \nAfter introducing the basic notions\, I will derive some properties of momentum images related to fundamental forms and osculating varieties\, as well as a lower bound on the minimal positive degree of a homogeneous invariant\, derived using secant varieties. At the end I will present a class of homogeneous projective varieties\, characterized by a special property of their secant varieties\, where the relations between the above three concepts take a particularly pristine form. \n\nInvariant theory\, homogeneous projective varieties\, and momentum maps\, course by Valdemar Tsanov \n\n 
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-11/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231121T140000
DTEND;TZID=Europe/Sofia:20231121T153000
DTSTAMP:20260614T205444
CREATED:20231010T091730Z
LAST-MODIFIED:20231010T091730Z
UID:15149-1700575200-1700580600@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 21.11.2023 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Валдемар Цанов\, ИМИ – БАН \nКурс: Invariant theory\, homogeneous projective varieties\, and momentum maps \nРезюме: Let \(f:K\to U(V)\) be a unitary representation of a compact Lie group \(K\) with Lie algebra \(\mathfrak k\). This series of talks will be devoted to some recent developments based on relations between the following three classical notions. \n\nThe ring of -invariant polynomials \(\mathbb C[V]^K\) is finitely generated by homogeneous elements\, by a theorem of Hilbert\, but the proof is notoriously nonconstructive. The degrees of a minimal set of generators are canonically determined by \(f\)\, and will be the focus of the discussion.\nThe \(K\)-equivariant momentum map \(\mu:\mathbb P(V)\to \mathfrak k^*\) associated to the Fubini-Study form encodes in its image properties of the invariant ring \(\mathbb C[V]^K\) and the \(K\)-module structure of the entire polynomial ring \(\mathbb C[V]\)\, due to theorems of Mumford and Brion. While many general properties of momentum images have been established\, explicit descriptions remain unknown in many cases south for in physics and quantum information theory.\nProjective geometry of complex \(K\)-orbits in \(\mathbb P(V)\); their fundamental forms\, osculating varieties and secant varieties.\n\nGeneral relations between the first two topics are well established\, even in a more general context. There are also well known relations between invariant theory and projective geometry\, but secant varieties have only recently been brought to the discussion and are subject of current interest. \nAfter introducing the basic notions\, I will derive some properties of momentum images related to fundamental forms and osculating varieties\, as well as a lower bound on the minimal positive degree of a homogeneous invariant\, derived using secant varieties. At the end I will present a class of homogeneous projective varieties\, characterized by a special property of their secant varieties\, where the relations between the above three concepts take a particularly pristine form. \n\nInvariant theory\, homogeneous projective varieties\, and momentum maps\, course by Valdemar Tsanov \n\n 
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-12/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231122T160000
DTEND;TZID=Europe/Sofia:20231122T173000
DTSTAMP:20260614T205444
CREATED:20231121T164225Z
LAST-MODIFIED:20231121T164225Z
UID:15481-1700668800-1700674200@math.bas.bg
SUMMARY:Семинар по геометрия на МЦМН
DESCRIPTION:Следващата сбирка на Семинара по геометрия на МЦМН\nще се проведе в сряда\, 22 ноември 2023 г. от 16:00 ч. в зала 403 и онлайн в Zoom:\n\n\nTopics in non-archimedean analytic geometry (II)\n\nby Jiachang Xu – International Center for Mathematical Sciences (ICMS – Sofia)\n\nZoom link:\n\nhttps://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bf%d0%be-%d0%b3%d0%b5%d0%be%d0%bc%d0%b5%d1%82%d1%80%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-3/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%98%D0%BD%D1%81%D1%82%D0%B8%D1%82%D1%83%D1%82%20%D0%BF%D0%BE%20%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20%D0%B8%20%D0%B8%D0%BD%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20-%20%D0%91%D0%90%D0%9D":MAILTO:office@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231123T140000
DTEND;TZID=Europe/Sofia:20231123T153000
DTSTAMP:20260614T205444
CREATED:20231010T091918Z
LAST-MODIFIED:20231010T091918Z
UID:15153-1700748000-1700753400@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 23.11.2023 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Валдемар Цанов\, ИМИ – БАН \nКурс: Invariant theory\, homogeneous projective varieties\, and momentum maps \nРезюме: Let \(f:K\to U(V)\) be a unitary representation of a compact Lie group \(K\) with Lie algebra \(\mathfrak k\). This series of talks will be devoted to some recent developments based on relations between the following three classical notions. \n\nThe ring of -invariant polynomials \(\mathbb C[V]^K\) is finitely generated by homogeneous elements\, by a theorem of Hilbert\, but the proof is notoriously nonconstructive. The degrees of a minimal set of generators are canonically determined by \(f\)\, and will be the focus of the discussion.\nThe \(K\)-equivariant momentum map \(\mu:\mathbb P(V)\to \mathfrak k^*\) associated to the Fubini-Study form encodes in its image properties of the invariant ring \(\mathbb C[V]^K\) and the \(K\)-module structure of the entire polynomial ring \(\mathbb C[V]\)\, due to theorems of Mumford and Brion. While many general properties of momentum images have been established\, explicit descriptions remain unknown in many cases south for in physics and quantum information theory.\nProjective geometry of complex \(K\)-orbits in \(\mathbb P(V)\); their fundamental forms\, osculating varieties and secant varieties.\n\nGeneral relations between the first two topics are well established\, even in a more general context. There are also well known relations between invariant theory and projective geometry\, but secant varieties have only recently been brought to the discussion and are subject of current interest. \nAfter introducing the basic notions\, I will derive some properties of momentum images related to fundamental forms and osculating varieties\, as well as a lower bound on the minimal positive degree of a homogeneous invariant\, derived using secant varieties. At the end I will present a class of homogeneous projective varieties\, characterized by a special property of their secant varieties\, where the relations between the above three concepts take a particularly pristine form. \n\nInvariant theory\, homogeneous projective varieties\, and momentum maps\, course by Valdemar Tsanov \n\n 
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-13/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231205T140000
DTEND;TZID=Europe/Sofia:20231205T153000
DTSTAMP:20260614T205444
CREATED:20231010T092252Z
LAST-MODIFIED:20231130T141804Z
UID:15157-1701784800-1701790200@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 05.12.2023 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Богдан Станков\, ИМИ – БАН \nДоклад: Recent developments in the study of Følner functions \nДопълнителна информация: https://icms.bg/recent-developments-in-the-study-of-folner-functions-talk-by-bogdan-stankov/
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-14/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231206T160000
DTEND;TZID=Europe/Sofia:20231206T173000
DTSTAMP:20260614T205444
CREATED:20231130T142439Z
LAST-MODIFIED:20231130T142439Z
UID:15607-1701878400-1701883800@math.bas.bg
SUMMARY:Семинар по геометрия на МЦМН
DESCRIPTION:Следващата сбирка на Семинара по геометрия на МЦМН\nще се проведе в сряда\, 6 декември 2023 г. от 16:00 ч. в зала 403 и онлайн в Zoom: \nДоклад на тема \n\nIntroduction to tropical modifications (II)\nще изнесе Никита Калинин\, Международен център по математически науки (МЦМН – София). \n\nZoom link:\n\nhttps://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bf%d0%be-%d0%b3%d0%b5%d0%be%d0%bc%d0%b5%d1%82%d1%80%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-4/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%98%D0%BD%D1%81%D1%82%D0%B8%D1%82%D1%83%D1%82%20%D0%BF%D0%BE%20%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20%D0%B8%20%D0%B8%D0%BD%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20-%20%D0%91%D0%90%D0%9D":MAILTO:office@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20231213T160000
DTEND;TZID=Europe/Sofia:20231213T173000
DTSTAMP:20260614T205444
CREATED:20231207T212005Z
LAST-MODIFIED:20231207T212005Z
UID:15684-1702483200-1702488600@math.bas.bg
SUMMARY:Семинар по геометрия на МЦМН
DESCRIPTION:Следващата сбирка на Семинара по геометрия на МЦМН\nще се проведе в сряда\, 13 декември 2023 г. от 16:00 ч. в зала 403 и онлайн в Zoom: \nДоклад на тема \n\nValuations of Higher Rank\nще изнесе Андрей Бенгуш-Ласние\, Международен център по математически науки (МЦМН – София). \n\nZoom link:\n\nhttps://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bf%d0%be-%d0%b3%d0%b5%d0%be%d0%bc%d0%b5%d1%82%d1%80%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-5/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%98%D0%BD%D1%81%D1%82%D0%B8%D1%82%D1%83%D1%82%20%D0%BF%D0%BE%20%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20%D0%B8%20%D0%B8%D0%BD%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20-%20%D0%91%D0%90%D0%9D":MAILTO:office@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240109T140000
DTEND;TZID=Europe/Sofia:20240109T153000
DTSTAMP:20260614T205444
CREATED:20240104T172534Z
LAST-MODIFIED:20240104T172819Z
UID:15789-1704808800-1704814200@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 09.01.2024 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: д-р Антони Рангачев\, ИМИ – БАН \nДоклад: Stratified Morse theory and the critical locus of a linear functional \nДопълнителна информация: https://icms.bg/stratified-morse-theory-and-the-critical-locus-of-a-linear-functional-talk-by-antony-rangachev/ \nРезюме. In this talk I will use stratified Morse theory to relate the number of critical points of a generic linear functional on a complex analytic manifold M to the Euler characteristics of M and a generic hyperplane slice of M.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-15/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240111T140000
DTEND;TZID=Europe/Sofia:20240111T153000
DTSTAMP:20260614T205444
CREATED:20240104T175203Z
LAST-MODIFIED:20240104T175203Z
UID:15795-1704981600-1704987000@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 11.01.2024 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: д-р Антони Рангачев\, ИМИ – БАН \nДоклад: The Milnor number of a smoothable curve \nДопълнителна информация: https://icms.bg/the-milnor-number-of-a-smoothable-curve-talk-by-antony-rangachev/ \nРезюме. In this talk I will derive an algebraic formula for the Milnor number of a smoothable complex analytic curve singularity X by relating it to the Euler characteristic of its smoothing\, which in turn I will relate to the multiplicity of the Jacobian ideal of X and and the multiplicity of X at its singular point. If time permits I will discuss generalizations to higher dimensions. This is a report on a joint work with Gaffney and Bengus-Lasnier. \n 
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-16/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240116T140000
DTEND;TZID=Europe/Sofia:20240116T153000
DTSTAMP:20260614T205444
CREATED:20240112T124026Z
LAST-MODIFIED:20240112T124026Z
UID:15841-1705413600-1705419000@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 16.01.2024 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Carlos Varea (Universidade Tecnológica  Federal do Paraná – Campus Cornélio Procópio\, Brazil) \nДоклад: The H-flux on flag manifolds generated by infinitesimal T-duality \nДопълнителна информация: https://icms.bg/the-h-flux-on-flag-manifolds-generated-by-infinitesimal-t-duality-talk-by-carlos-varea/ \nРезюме. In this talk we present a new correspondence for pairs \((\mathbb{F}\,H)\) formed by a flag manifold \(\mathbb{F}\) together with an $H$-flux on \(\mathbb{F}\). Given its role within our correspondence\, infinitesimal \(T\)-duality may be viewed as a source of \(H\)-flux\, in the sense that it contributes towards taking fluxless pairs \((\mathbb{F}\,0)\) to pairs \((\mathbb{F}^\vee\, H^\vee)\) carrying nontrivial flux \(H^\vee\neq 0\). We also illustrate how our correspondence exchanges complex structures with symplectic ones up to \(B\)-transformations. This is a joint work with Elizabeth Gasparim and Lino Grama.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-17/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240118T130000
DTEND;TZID=Europe/Sofia:20240118T143000
DTSTAMP:20260614T205444
CREATED:20240110T072831Z
LAST-MODIFIED:20240114T173529Z
UID:15812-1705582800-1705588200@math.bas.bg
SUMMARY:Съвместно заседание на Семинара на секция „Алгебра и логика” и Семинара на МЦМН
DESCRIPTION:На 18 януари 2024 г. (четвъртък) от 13:00 часа в зала 403 на ИМИ-БАН и онлайн чрез платформата zoom ще се проведе съвместно заседание на \nСеминара на секция „Алгебра и логика” \nи Семинара на Международния център по математически науки към ИМИ-БАН. \nДоклад на тема \nNilpotent algebras\, groups and beyond\nще изнесе Yuri Bahturin (Memorial University of Newfoundland\, Canada) (joint work with Alexander Olshanskii). \nАбстракт: We study various correspondences between finite-dimensional nilpotent algebras and (quasi)groups similar to those given by the circle product in the case of associative algebras or by the Baker-Campbell-Hausdorff formulas in the the case of Lie algebras or their generalizations. In the particular case of Malcev’s correspondence\, we obtain some new results about groups using Lie algebras and vice versa. \nЛинк към zoom-стаята на семинара:\nhttps://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 \nПоканват се всички желаещи да присъстват. \nОт секция „Алгебра и логика” и МЦМН\nhttp://www.math.bas.bg/algebra/seminarAiL/\nhttps://icms.bg/category/icms-seminar/\n===================================================
URL:https://math.bas.bg/event/%d1%81%d1%8a%d0%b2%d0%bc%d0%b5%d1%81%d1%82%d0%bd%d0%be-%d0%b7%d0%b0%d1%81%d0%b5%d0%b4%d0%b0%d0%bd%d0%b8%d0%b5-%d0%bd%d0%b0-%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80%d0%b0-%d0%bd%d0%b0-%d1%81%d0%b5/
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:20240124T160000
DTEND;TZID=Europe/Sofia:20240124T173000
DTSTAMP:20260614T205444
CREATED:20240122T092832Z
LAST-MODIFIED:20240122T092833Z
UID:15875-1706112000-1706117400@math.bas.bg
SUMMARY:Семинар по геометрия на МЦМН
DESCRIPTION:Следващата сбирка на Семинара по геометрия на МЦМН\nще се проведе в сряда\, 24 януари 2024 г. от 16:00 ч. в зала 403 и онлайн в Zoom: \nДоклад на тема \nIntroduction to Derived Algebraic Geometry and deformation theory\n\nще изнесе Инди Чин\, ИМИ – БАН. \n\nZoom link:\n\nhttps://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bf%d0%be-%d0%b3%d0%b5%d0%be%d0%bc%d0%b5%d1%82%d1%80%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-6/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%98%D0%BD%D1%81%D1%82%D0%B8%D1%82%D1%83%D1%82%20%D0%BF%D0%BE%20%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20%D0%B8%20%D0%B8%D0%BD%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20-%20%D0%91%D0%90%D0%9D":MAILTO:office@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240130T140000
DTEND;TZID=Europe/Sofia:20240130T153000
DTSTAMP:20260614T205444
CREATED:20240126T111458Z
LAST-MODIFIED:20240126T111458Z
UID:15887-1706623200-1706628600@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 30.01.2024 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Владимир Митанкин\, ИМИ – БАН \nДоклад: Density of Hasse failures for diagonal affine cubic surfaces \nДопълнителна информация: https://icms.bg/density-of-hasse-failures-for-diagonal-affine-cubic-surfaces-a-talk-by-vladimir-mitankin/ \nРезюме. А question of Mordell asks which integers are the sum of three cubes provided that there are no local obstructions to that. While Mordell’s question seems out of reach with the current machinery\, it is widely believed that every integer not congruent to 4 or 5 mod 9 is a sum of three integral cubes. If\, instead of the sum of three cubes\, a general ternary cubic is considered\, local conditions no longer suffice for solubility\, i.e. the integral Hasse principle may fail. In this talk we shall apply the integral version of the Brauer-Manin obstruction to construct the first examples of such failures not explained by local conditions in the setting of affine diagonal ternary cubics. We will then explore in three different natural ways how such failures are distributed across the family of affine diagonal ternary cubics. \nThis talk is based on a joint work with Harkaran Uppal and Julian Lyczak.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-18/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240131T160000
DTEND;TZID=Europe/Sofia:20240131T173000
DTSTAMP:20260614T205444
CREATED:20240130T125552Z
LAST-MODIFIED:20240130T125552Z
UID:15893-1706716800-1706722200@math.bas.bg
SUMMARY:Семинар по геометрия на МЦМН
DESCRIPTION:Следващата сбирка на Семинара по геометрия на МЦМН\nще се проведе в сряда\, 31 януари 2024 г. от 16:00 ч. в зала 403 и онлайн в Zoom: \nДоклад на тема \nDerived Deformation Theory and Formal Moduli Problem\n\nще изнесе Инди Чин\, МЦМН и ИМИ – БАН. \n\nZoom link:\n\nhttps://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09\n\nAbstract: Derived deformation theory studies the formal neighborhoods of moduli spaces. The classical work of Kodaira-Spencer on deformation of complex manifolds tells that the dg Lie algebra A^(0\,*)(X\,TX) controls the deformations of the complex manifold. The example illustrates the following general principle: A dg Lie algebra gives rise to a deformation functor by considering the  Maurer-Cartan elements of the dg Lie algebra tensoring with the maximal ideal of an Artin local ring. This idea is explored by many people\, including  Quillen\, Deligne\, Drinfeld\,  Kapranov and Kontesevich. Later\, Lurie and Pridham independently proved that the category of dg Lie algebra is indeed equivalent to the category of Formal Moduli problem. I will state their results and explain the idea of the proof.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bf%d0%be-%d0%b3%d0%b5%d0%be%d0%bc%d0%b5%d1%82%d1%80%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-7/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%98%D0%BD%D1%81%D1%82%D0%B8%D1%82%D1%83%D1%82%20%D0%BF%D0%BE%20%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20%D0%B8%20%D0%B8%D0%BD%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20-%20%D0%91%D0%90%D0%9D":MAILTO:office@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240206T140000
DTEND;TZID=Europe/Sofia:20240206T153000
DTSTAMP:20260614T205444
CREATED:20240205T114758Z
LAST-MODIFIED:20240205T120046Z
UID:15908-1707228000-1707233400@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 06.02.2024 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Paul Horja\, University of Miami\, USA \nДоклад: A categorical view of singularity theory I \nДопълнителна информация: https://icms.bg/a-categorical-view-of-singularity-theory-i-and-ii-talks-by-paul-horja/ \nРезюме. The mirror symmetry phenomenon was discovered by string theorists more than thirty years ago as an equivalence of two physical theories associated with very different geometries. The categorical point of view on this remarkable conjecture was famously introduced by M. Kontsevich in his 1994 ICM talk. As it became clear over time\, homological mirror symmetry provides new approaches to many topics in symplectic and algebraic geometry. In these two talks\, I will present a brief overview of the conjecture as well as some results inspired by mirror symmetry and obtained in joint work with L. Katzarkov about classical problems on discriminants and singularity theory.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-19/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240207T160000
DTEND;TZID=Europe/Sofia:20240207T173000
DTSTAMP:20260614T205444
CREATED:20240205T211554Z
LAST-MODIFIED:20240205T211820Z
UID:15925-1707321600-1707327000@math.bas.bg
SUMMARY:Семинар по геометрия на МЦМН
DESCRIPTION:Следващата сбирка на Семинара по геометрия на МЦМН\nще се проведе в сряда\, 7 февруари 2024 г. от 16:00 ч. в зала 403 и онлайн в Zoom: \nДоклад на тема \nIntroduction to curve counting\n\nще изнесе Михаил Школников\, ИМИ – БАН. \n\nZoom link:\n\nhttps://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09\n\nAbstract: This talk is intended as a very gentle introduction to the classical subject of enumerative geometry concerned with problems of counting algebraic curves with prescribed properties. In the realm of classical planimetry\, we know that there exists a single circle passing through a collection of three points\, provided that these points are generic. Here “generic” simply means that the points are not collinear\, i.e. don’t belong to the same line but could refer to some other open condition in a different context; the number of points is just right for a problem to be well-stated — there are infinitely many circles passing through any two points and a collection of four points lying on a circle is special. A less trivial example\, which will be considered in detail\, is the question “How many rational cubic curves on the plane pass through a generic collection of eight points?”. “Rational” here means that a curve has a parametrization by rational functions\, and “cubic” refers to a curve defined as a zero locus of a degree three polynomial. The number of points is again chosen just right so that one may expect a non-trivial answer. In the case of real algebraic geometry\, the number of cubics may vary depending on the position of the eight generic points\, and a priori it is even not clear if such curves exist for all configurations. On the other hand\, if we state the same problem over complex numbers the answer becomes definite and independent of the position of the generic points. By an elegant\, yet quite elementary\, topological reasoning we will deduce that this answer is 12. Adapting the same argument in the real case\, we will see that real rational cubics should be counted with signs and the result of this new count becomes a definite -8\, proving in particular that for any generic configuration of eight points on the real plane\, there exist at least eight rational real cubics passing through them.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bf%d0%be-%d0%b3%d0%b5%d0%be%d0%bc%d0%b5%d1%82%d1%80%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-8/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%98%D0%BD%D1%81%D1%82%D0%B8%D1%82%D1%83%D1%82%20%D0%BF%D0%BE%20%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20%D0%B8%20%D0%B8%D0%BD%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20-%20%D0%91%D0%90%D0%9D":MAILTO:office@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240208T140000
DTEND;TZID=Europe/Sofia:20240208T153000
DTSTAMP:20260614T205444
CREATED:20240205T115818Z
LAST-MODIFIED:20240205T120340Z
UID:15912-1707400800-1707406200@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 08.02.2024 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Paul Horja\, University of Miami\, USA \nДоклад: A categorical view of singularity theory II \nДопълнителна информация: https://icms.bg/a-categorical-view-of-singularity-theory-i-and-ii-talks-by-paul-horja/ \nРезюме. The mirror symmetry phenomenon was discovered by string theorists more than thirty years ago as an equivalence of two physical theories associated with very different geometries. The categorical point of view on this remarkable conjecture was famously introduced by M. Kontsevich in his 1994 ICM talk. As it became clear over time\, homological mirror symmetry provides new approaches to many topics in symplectic and algebraic geometry. In these two talks\, I will present a brief overview of the conjecture as well as some results inspired by mirror symmetry and obtained in joint work with L. Katzarkov about classical problems on discriminants and singularity theory.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-20/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240213T140000
DTEND;TZID=Europe/Sofia:20240213T153000
DTSTAMP:20260614T205444
CREATED:20240209T094253Z
LAST-MODIFIED:20240209T094439Z
UID:15953-1707832800-1707838200@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 13.02.2024 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Jean-Pierre Gazeau (APC\, Université Paris – Cité) \nДоклад: Quantum circuit complexity for light polarisation or complexity with no complex numbers \nДопълнителна информация: https://icms.bg/quantum-circuit-complexity-for-light-polarisation-or-complexity-with-no-complex-number-talk-by-jean-pierre-gazeau/ \nРезюме. I will present a form of quantum circuit complexity that extends to open systems. To illustrate the methodology\, I focus on a basic model where the Hilbert space of states is represented by the Euclidean plane. Specifically\, the investigation is about the dynamics of mixed quantum states as they undergo interactions with a sequence of gates. The approach involves the analysis of sequences of density matrices. Each density matrix evolves within the framework of a Gorini-Kossakowski-Lindblad-Sudarshan (GKLS) process during the time interval between consecutive gates. Notably\, when considering an upper limit for the cost function\, the optimal number of gates follows a power-law relationship.
URL:https://math.bas.bg/event/copy-%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240214T160000
DTEND;TZID=Europe/Sofia:20240214T173000
DTSTAMP:20260614T205444
CREATED:20240212T133658Z
LAST-MODIFIED:20240212T133658Z
UID:15958-1707926400-1707931800@math.bas.bg
SUMMARY:Семинар по геометрия на МЦМН
DESCRIPTION:Следващата сбирка на Семинара по геометрия на МЦМН\nще се проведе в сряда\, 14 февруари 2024 г. от 16:00 ч. в зала 403 и онлайн в Zoom: \nДоклад на тема \nRefined curve counting\n\nще изнесе Михаил Школников\, ИМИ – БАН. \n\nZoom link:\n\nhttps://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09\n\nAbstract: Refining an enumerative problem upgrades the numerical solution to a polynomial so that its specialization gives the original number. A prototypical example of such refinement arises in the tropical curve counting from replacing Mikhalkin multiplicities\, corresponding to counting complex curves\, with Block-Goettsche multiplicities. I will speak about the invariance of this count and its various interpretations.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bf%d0%be-%d0%b3%d0%b5%d0%be%d0%bc%d0%b5%d1%82%d1%80%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-9/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%98%D0%BD%D1%81%D1%82%D0%B8%D1%82%D1%83%D1%82%20%D0%BF%D0%BE%20%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20%D0%B8%20%D0%B8%D0%BD%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20-%20%D0%91%D0%90%D0%9D":MAILTO:office@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240228T160000
DTEND;TZID=Europe/Sofia:20240228T173000
DTSTAMP:20260614T205444
CREATED:20240222T091637Z
LAST-MODIFIED:20240222T091637Z
UID:15979-1709136000-1709141400@math.bas.bg
SUMMARY:Семинар по геометрия на МЦМН
DESCRIPTION:Следващата сбирка на Семинара по геометрия на МЦМН\nще се проведе в сряда\, 28 февруари 2024 г. от 16:00 ч. в зала 403 и онлайн в Zoom: \nДоклад на тема \nLinear embeddings of complex Grassmannians\n\nще изнесе Иван Пенков\, Constructor University Bremen. \n\nZoom link:\n\nhttps://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09\n\nAbstract: A linear embedding of Grassmannians\, one of which could possibly be isotropic\, is an embedding which respects the generators of Picard groups. Several years ago A.S. Tikhomirov and I classified such embeddings when both Grassmannians are simultaneously usual Grassmannians or isotropic Grassmannians of the same type(orthogonal or symplectic). In this talk I will discuss also the mixed case. A classification as above has an application to the classification of infinite-dimensional linear ind-Grassmannians\, and I shall  briefly explain this at the end of the talk.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bf%d0%be-%d0%b3%d0%b5%d0%be%d0%bc%d0%b5%d1%82%d1%80%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-10/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
ORGANIZER;CN="%D0%98%D0%BD%D1%81%D1%82%D0%B8%D1%82%D1%83%D1%82%20%D0%BF%D0%BE%20%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20%D0%B8%20%D0%B8%D0%BD%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0%20-%20%D0%91%D0%90%D0%9D":MAILTO:office@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240312T140000
DTEND;TZID=Europe/Sofia:20240312T153000
DTSTAMP:20260614T205444
CREATED:20240311T225834Z
LAST-MODIFIED:20240311T225834Z
UID:16009-1710252000-1710257400@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 12.03.2024 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Morgan Brown  (University of Miami) \nДоклад: The Cox ring perspective on birational geometry \nДопълнителна информация: https://icms.bg/the-cox-ring-perspective-in-birational-geometry-talk-by-morgan-brown/ \nРезюме. The Mori program for birational classification of algebraic varieties attempts to classify algebraic varieties by producing canonical models\, polarized by the canonical class. This is accomplished through a series of algebraic surgery operations\, such as flips\, flops\, and divisorial contractions. A complementary viewpoint is that of the total coordinate ring or Cox ring. Here birational maps are understood by looking at the totality of all linear series on the variety\, endowed with a ring structure directly analogous to that of the homogeneous coordinate ring of a projective variety. I will give an overview of how Cox rings can help clarify many phenomena in birational geometry.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-21/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20240314T140000
DTEND;TZID=Europe/Sofia:20240314T153000
DTSTAMP:20260614T205444
CREATED:20240311T230335Z
LAST-MODIFIED:20240311T230335Z
UID:16014-1710424800-1710430200@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Дата: 14.03.2024 г.\, 14:00 ч. \nМясто: Зала 403\, ИМИ – БАН \nДокладчик: Morgan Brown  (University of Miami) \nДоклад: Cox rings and characterization of toric varieties \nДопълнителна информация: https://icms.bg/the-cox-ring-perspective-in-birational-geometry-talk-by-morgan-brown/ \nРезюме. Recently Moraga and Svaldi proved a conjecture of Shokoruv\, characterizing in the relative case toroidal morphisms as those which admit divisors with many components relative to the Picard rank. I will discuss the global version\, proved in previous joint work with McKernan\, Svaldi and Zong. The proof relies on characterizing the singularity type of the Cox ring\, giving another example of the use of these invariants in birational geometry.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d0%bc%d1%86%d0%bc%d0%bd-22/
LOCATION:Институт по математика и информатика – БАН\, Block 8\, 1113 БАН IV км.\, София\, Bulgaria
CATEGORIES:Редовен семинар
END:VEVENT
END:VCALENDAR