Следващата сбирка на Семинара по геометрия на МЦМН ще се проведе в сряда, 24 април 2024 г. от 16:00 ч. в зала 403: Доклад на тема Generalised Plucker formula ще изнесе Андрей Бенгуш-Ласние, МЦМН. Abstract: In order to classify objects in singularity theory and algebraic geometry, we define invariants associated to varieties or germs of singularities and hope to have enough tools to compute them easily. From classical projective duality, for any variety X , we can define a dual variety X∗ and we call the class of X the degree of X∗ . Plücker’s formula allows one to compute this class for plane curves with a certain set of nodes, cusps and tacnodes. We will start our talk by recalling the [...]

Следващата сбирка на Семинара по геометрия на МЦМН ще се проведе в сряда, 27 март 2024 г. от 16:00 ч. в зала 403: Доклад на тема Reading seminar of geometric Lubin-Tate theory ще изнесе Jiachang Xu, ИМИ - БАН. Abstract: This is reading seminar of geometry of Lubin-Tate theory, our goal is to understand the papers “M. J. Hopkins and B. H. Gross, Equivariant vector bundles on the Lubin-Tate moduli space” and “Ramero, Lorenzo On a class of étale analytic sheaves”. The first seminar we plan to go over the basis of deformation theory, formal group and necessary rigid geometry. Zoom link: https://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09

Следващата сбирка на Семинара по геометрия на МЦМН ще се проведе в сряда, 20 март 2024 г. от 16:00 ч. в зала 403: Доклад на тема Ellipsoid superpotentials: obstructing symplectic embeddings by singular algebraic curves ще изнесе Григори Михалкин, Женевски университет. Abstract: How singular can be a local branch of a plane algebraic curve of a given degree d? A remarkable series of real algebraic curves was constructed by Stepan Orevkov. It is based on even-indexed numbers in the Fibonacci series: a degree 5 curve with a 13/2 cusp, a degree 13 curve with a 34/5-cusp, and so on. We discuss this and other series of algebraic curves in the context of the problem of symplectic packing of an ellipsoid into a ball, with [...]

Следващата сбирка на Семинара по геометрия на МЦМН ще се проведе в сряда, 28 февруари 2024 г. от 16:00 ч. в зала 403 и онлайн в Zoom: Доклад на тема Linear embeddings of complex Grassmannians ще изнесе Иван Пенков, Constructor University Bremen. Zoom link: https://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09 Abstract: 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 [...]

Следващата сбирка на Семинара по геометрия на МЦМН ще се проведе в сряда, 14 февруари 2024 г. от 16:00 ч. в зала 403 и онлайн в Zoom: Доклад на тема Refined curve counting ще изнесе Михаил Школников, ИМИ - БАН. Zoom link: https://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09 Abstract: 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.

Следващата сбирка на Семинара по геометрия на МЦМН ще се проведе в сряда, 7 февруари 2024 г. от 16:00 ч. в зала 403 и онлайн в Zoom: Доклад на тема Introduction to curve counting ще изнесе Михаил Школников, ИМИ - БАН. Zoom link: https://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09 Abstract: 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 [...]

Следващата сбирка на Семинара по геометрия на МЦМН ще се проведе в сряда, 31 януари 2024 г. от 16:00 ч. в зала 403 и онлайн в Zoom: Доклад на тема Derived Deformation Theory and Formal Moduli Problem ще изнесе Инди Чин, МЦМН и ИМИ - БАН. Zoom link: https://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09 Abstract: 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 [...]

Следващата сбирка на Семинара по геометрия на МЦМН ще се проведе в сряда, 24 януари 2024 г. от 16:00 ч. в зала 403 и онлайн в Zoom: Доклад на тема Introduction to Derived Algebraic Geometry and deformation theory ще изнесе Инди Чин, ИМИ - БАН. Zoom link: https://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09

Следващата сбирка на Семинара по геометрия на МЦМН ще се проведе в сряда, 13 декември 2023 г. от 16:00 ч. в зала 403 и онлайн в Zoom: Доклад на тема Valuations of Higher Rank ще изнесе Андрей Бенгуш-Ласние, Международен център по математически науки (МЦМН - София). Zoom link: https://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09

Следващата сбирка на Семинара по геометрия на МЦМН ще се проведе в сряда, 6 декември 2023 г. от 16:00 ч. в зала 403 и онлайн в Zoom: Доклад на тема Introduction to tropical modifications (II) ще изнесе Никита Калинин, Международен център по математически науки (МЦМН - София). Zoom link: https://us02web.zoom.us/j/83740034721?pwd=VnBtcVpGUktscHQ4a09jZkNZTURyZz09