The MathNet Korea
Information Center for Mathematical Science

세미나

Information Center for Mathematical Science

세미나

연세대학교 수학과 세미나

아주대학교 수학과 세미나

Toric topology is the study of topological spaces with particularly good torus symmetry. Those spaces, called (real) toric spaces, can be represented by a simplicial sphere $K$ and additional combinatorial information. Real toric manifolds and real moment-angle manifolds are examples of real toric spaces.

아주대학교 수학과 세미나

Given $v,w\in \mathfrak{S}_n$ with $v\leq w$, the Richardson variety~$X^v_w$ is the intersection of the Schubert variety$X_w$ and the opposite Schubert variety $X^v$. A Bruhat interval polytope~$Q_{v,w}$ is the convex hull of all permutation vectors $x = (x(1), x(2), . . . , x(n))$ with $v\leq x\leq w$. It is known that $Q_{v^{-1},w^{-1}}$ is the moment map image of $X^v_w\subset\mathrm{Fl}(\mathbb{C}^n)$. In this talk, we discuss the properties of Bruhat interval polytopes and some open problems.

아주대학교 수학과 세미나

In this talk, we discuss a certain integrable system, called a Gelfand-Cetlin system defined on a flag variety of type A, B, and D. We first illustrate the similarity and the difference between a GC system and a toric moment map, and explain an algorithm which allows us to “read off” the topology of a Gelfand-Cetlin fiber from the combinatorics of its image, called a Gelfand-Cetlin polytope. We also discuss so-called a string polytope, which can be thought of as a generalization of a Gelfand-Cetlin polytope, and related open questions. This is based on joint work with Yoosik Kim, and partially with Yoosik Kim, Eunjeong Lee and Kyeong-Dong Park.

POSTECH 세미나

POSTECH IBS-CGP Seminar
  • Title : Aboreal singularites
  • Speaker : Byung-Hee Ahn
  • Data : 2019-02-13 13:30:00
  • Host : IBS
  • Place :

POSTECH IBS-CGP Seminar

POSTECH IBS-CGP Seminar
  • Title : T-structures
  • Speaker : Taesu Kim
  • Data : 2019-02-12 13:30:00
  • Host : IBS
  • Place :

POSTECH IBS-CGP Seminar

POSTECH IBS-CGP Seminar

POSTECH IBS-CGP Seminar

POSTECH IBS-CGP Seminar

POSTECH IBS-CGP Seminar

POSTECH IBS-CGP Seminar
  • Title : Lectures on SYZ (I)
  • Speaker : Yat-Hin Suen
  • Data : 2019-01-28 16:00:00
  • Host : IBS
  • Place :

POSTECH 세미나

POSTECH IBS-CGP Seminar

POSTECH IBS-CGP Seminar

2019 서울대학교 수리과학부 세미나

In this talk, the multi-agent collective behaviors and some of their potential applications are briefly reviewed. In particular, the consensus problem in multi-agent systems with first-order, second-order, and higher-order dynamics is investigated in details. Then, some extensions and recent progress for general protocols in multi-agent systems will be given. Furthermore, the new directions and challenges for the research work on this topic will be discussed.

2019 서울대학교 수리과학부 세미나
  • Title : Root numbers II
  • Speaker : 한겨울
  • Data : 2019-02-14 14:00:00
  • Host : SNU
  • Place :

A root number is one of the important notions in number theory. I will introduce several ways to define root numbers and the relations among them.

2019 서울대학교 수리과학부 세미나

The starting point of the lecture is the classical Heron’s formula that relates the area of a triangle to its side lengths.We discuss its non-euclidean versions know for a long time. Then we describe possible statements of the Brahmagupta’s formula for area of an inscribed quadrilateral on the Euclidean, spherical and hyperbolic planes. The natural generalization of these results is the Bretschneider for area of an arbitrary quadrilateral. The next subject will be the Pythagorus theorem for triangles and tetrahedrons in all the three spaces of constant curvature. We discuss also some other identities for triangles and tetrahedrons with addition properties.