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X-WR-CALDESC:Събития за Institute of Mathematics and Informatics
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DTSTART;TZID=Europe/Sofia:20250507T160000
DTEND;TZID=Europe/Sofia:20250507T173000
DTSTAMP:20260421T073159
CREATED:20250505T165639Z
LAST-MODIFIED:20250505T170018Z
UID:17708-1746633600-1746639000@math.bas.bg
SUMMARY:Семинар по геометрия на МЦМН
DESCRIPTION:Следващата сбирка на Семинара по геометрия на МЦМН\nще се проведе в сряда\, 7 май 2025 г. от 16:00 ч. в зала 403 и онлайн в Zoom: \nДоклад на тема \nBinary Quadratic Forms and Conway’s Topographs (Lecture 2 of 3)\n\nще изнесе Nikita Kalinin\, Guangdong Technion Israel Institute of Technology. \n\nСледващата лекция ще бъде на 14.05.2025 от 16:00 ч.\n\nAbstract: Binary quadratic forms are as elementary as they are mysterious—much like prime numbers. In 1997\, John Conway introduced topographs\, a powerful geometric tool that provides a geometric visualization of binary quadratic forms and their values. These lectures will explore how topographs\, combined with telescoping summation techniques\, yield elegant formulas — some with intuitive geometric interpretations. For instance\, consider the following result: \nLet \n\(A = \big\{ (x\, y) \mid  x\,y\in \mathbb{Z}_{\geq 0}^2\, \det(x \ \ y) = 1 \big\}\,\) \nthe set of pairs of lattice vectors in the first quadrant spanning a parallelogram of oriented area 1. Then\, \n\(4 \displaystyle\sum_{(x\,y) \in A} \frac{1}{|x|^2 \cdot |y|^2 \cdot |x+y|^2} = \pi.\) \nLecture Outline \n1. Introduction to Binary Quadratic Forms and Conway’s Topographs\nWe will begin with the basics of binary quadratic forms and their classification\, followed by an introduction to Conway’s topographs—a visual and geometric framework for understanding them. \n2. Class Number Formula and Summation over Topographs\nBuilding on the first lecture\, we will explore the class number formula and how summation identities arise naturally from the structure of topographs. \n3. Evaluation of Lattice Sums via Telescoping over Topographs\nThe final lecture will focus on telescoping techniques\, demonstrating how they can be used to evaluate intricate lattice sums—such as the one above—with geometric meaning. \n\n\nZoom link:\nhttps://us02web.zoom.us/j/86186281353?pwd=6CARUygJaA3HiTNAt3norZQRFt8fIL.1\n\nВидеозапис и презентация на първата лекция:\n\nhttps://youtu.be/z7Pz33JyCuA?si=rQ2L4yXJHMdiDkpe\nhttps://kilin-math.github.io/assets/numbers/telescopic_presentation1.pdf
URL:https://math.bas.bg/event/copy-%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
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BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20250513T140000
DTEND;TZID=Europe/Sofia:20250513T151500
DTSTAMP:20260421T073159
CREATED:20250512T114627Z
LAST-MODIFIED:20250512T115322Z
UID:17734-1747144800-1747149300@math.bas.bg
SUMMARY:Семинар на МЦМН
DESCRIPTION:Сбирка на семинара на МЦМН ще се проведе на 13.05.2025 г. (вторник) от 14:00 ч. в зала 403 на ИМИ – БАН. \nДокладчик: Milan Zlatanovic (University of Niš) \nДоклад: Non-symmetric gravitational theorys \nРезюме: We will consider a connection with totally skew-symmetric torsion on non-symmetric (semi-) Riemann manifolds that satisfy Einstein’s metric condition (EMC). We proved that an almost Hermitian manifold is a non-symmetric Riemann manifold that satisfies EMC if and only if it is a Nearly Kahler manifold. We will also show what happens in the case of para Hermitian manifold\, contact\, and para-contact manifolds that satisfy EMC. We show that a connection with skew symmetric torsion satisfying EMC exists on an almost contact metric manifolds when it is D-homothetic to a cosymplectic manifold. We proved the structure theorem for the new class of almost contact metric manifold and special attention we have focused on dimension 5. As a natural continuation of this research\, we dealt with the case of Lorentzian manifolds. \nThis is joint work with Stefan Ivanov and Nikola Stanchev.\nДопълнителна информация: https://icms.bg/category/icms-seminar/ \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-31/
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:20250513T151500
DTEND;TZID=Europe/Sofia:20250513T163000
DTSTAMP:20260421T073159
CREATED:20250507T203646Z
LAST-MODIFIED:20250512T114647Z
UID:17728-1747149300-1747153800@math.bas.bg
SUMMARY:Встъпителна лекция на доц. Михаил Школников
DESCRIPTION:Встъпителната лекция на доцент Михаил Школников в секция Анализ\, геометрия и топология на ИМИ-БАН ще се проведе на 13.05.2025 г. (вторник) от 15:15 ч. в зала 403 на ИМИ – БАН. \nДокладчик: Михаил Школников (ИМИ – БАН) \nДоклад: Introduction to amoebas and tropicalization \nРезюме: We will start by reviewing the most classical aspects of the theory of amoebas deeply rooted in complex analysis and geometry. Next\, we will pass to the notion of a tropical limit of amoebas\, and will see how restoring the phase allows to recover topology and deduce intersection-theoretic results. After that\, we will discuss some results (and their limitations) obtained with Grigory Mikhalkin in the context of non-commutative versions of amoebas of surfaces and tropical limits of curves inside the special matrix group SL(2\,C). I will conclude by sketching a proof of the complete description of possible tropicalizations of families of analytic surfaces in SL(2\,C) recently obtained with Peter Petrov\, in particular\, motivating our ongoing project on the non-commutative phase tropicalization\, a few words about which will be said if time permits. \n  \n 
URL:https://math.bas.bg/event/%d0%b2%d1%81%d1%82%d1%8a%d0%bf%d0%b8%d1%82%d0%b5%d0%bb%d0%bd%d0%b0-%d0%bb%d0%b5%d0%ba%d1%86%d0%b8%d1%8f-%d0%bd%d0%b0-%d0%b4%d0%be%d1%86-%d1%88%d0%ba%d0%be%d0%bb%d0%bd%d0%b8%d0%ba%d0%be%d0%b2-%d0%b8/
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%BD%D0%B0%D0%BB%D0%B8%D0%B7%2C%20%D0%B3%D0%B5%D0%BE%D0%BC%D0%B5%D1%82%D1%80%D0%B8%D1%8F%20%D0%B8%20%D1%82%D0%BE%D0%BF%D0%BE%D0%BB%D0%BE%D0%B3%D0%B8%D1%8F":MAILTO:vmil@math.bas.bg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20250514T150000
DTEND;TZID=Europe/Sofia:20250514T163000
DTSTAMP:20260421T073159
CREATED:20250507T080719Z
LAST-MODIFIED:20250507T080719Z
UID:17718-1747234800-1747240200@math.bas.bg
SUMMARY:Семинар на секция "Изследване на операциите\, вероятности и статистика"
DESCRIPTION:На 14 май (сряда) от 15:00 ч. в зала 503 на ИМИ\nще се състои сбирка на Семинара на секция ИОВС.  Доклад на тема: \nBusy Beaver за n=5\, или колко сложни са простите програми\nще изнесе д-р Георги Георгиев от ФМИ на СУ. \nРезюме. Колко дълго може да работи машина на Тюринг с 5 състояния и азбука {0\,1}\, преди да спре?\nВ началото лентата е запълнена с нули.\nИзвестна под името „Busy Beaver за n=5“ или BB(5)\, задачата е разбираема за всеки ученик\, който се интересува от програмиране.\nРешаването ѝ продължи 40 години и демонстрира колко сложен е семантичният анализ дори на микроскопични програми. \nИсторията бе разказана увлекателно преди година в списанието Quanta Magazine:\nhttps://www.quantamagazine.org/amateur-mathematicians-find-fifth-busy-beaver-turing-machine-20240702/. \nЩе разкажа за моето участие в решаването на задачата и за връзката ѝ с фундаменталните ограничения на методите за математическо и научно изследване.
URL:https://math.bas.bg/event/%d1%81%d0%b5%d0%bc%d0%b8%d0%bd%d0%b0%d1%80-%d0%bd%d0%b0-%d1%81%d0%b5%d0%ba%d1%86%d0%b8%d1%8f-%d0%b8%d0%b7%d1%81%d0%bb%d0%b5%d0%b4%d0%b2%d0%b0%d0%bd%d0%b5-%d0%bd%d0%b0-%d0%be%d0%bf%d0%b5%d1%80%d0%b0-7/
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%98%D0%B7%D1%81%D0%BB%D0%B5%D0%B4%D0%B2%D0%B0%D0%BD%D0%B5%20%D0%BD%D0%B0%20%D0%BE%D0%BF%D0%B5%D1%80%D0%B0%D1%86%D0%B8%D0%B8%D1%82%D0%B5%2C%20%D0%B2%D0%B5%D1%80%D0%BE%D1%8F%D1%82%D0%BD%D0%BE%D1%81%D1%82%D0%B8%20%D0%B8%20%D1%81%D1%82%D0%B0%D1%82%D0%B8%D1%81%D1%82%D0%B8%D0%BA%D0%B0":MAILTO:jeni@math.bas.bg;
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Sofia:20250516T130000
DTEND;TZID=Europe/Sofia:20250516T140000
DTSTAMP:20260421T073159
CREATED:20250514T091148Z
LAST-MODIFIED:20250514T091148Z
UID:17742-1747400400-1747404000@math.bas.bg
SUMMARY:Семинар "Алгебра и логика"
DESCRIPTION:На 16 май 2025 г. (петък) от 13:00 часа в зала 503 на ИМИ\nи онлайн чрез платформата zoom ще се проведе хибридно заседание на семинара по „Алгебра и логика”. \nДоклад на тема: \nGrätzer-Schmidt Theorem in arithmetical transfinite recursion\nще изнесе \nSoowhan Yoon\n(American University in Bulgaria).\nAbstract: We assess the reverse mathematical strength of the Grätzer-Schmidt theorem (GS) as a principle in second order arithmetic. The theorem GS was studied in an article by Katie Brodhead\, Mushfeq Khan\, Bjørn Kjos-Hanssen\, William A. Lampe\, Paul Kim Long V. Nguyen\, and Richard A. Shore\, where they establish the provability of GS in Π11 Comprehension (Π11-CA0) and its restrictive variant GSD in arithmetical comprehension (ACA0). It will be shown that the arithmetical transfinite recursion (ATR0) is sufficient to prove GS. Additionally\, other variants of GS will be explored as well. Some will be proved in ACA0\, while others will be shown equivalent to ATR0 over ACA0. Then\, we will discuss these results in the context of “Almost Theorems of Hyperarithmetic Analysis” (ATHA) by Shore in 2023. \n\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” 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%b0-120/
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
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