Thursday, June 27, 2024

2024-06-28 / 11:00 ~ 12:00

학과 세미나/콜로퀴엄 - 기타: Introduction to Milnor K-theory and its historical perspectives

by 사킵 무쉬타크 샤(Indian Statistical Institute - Bangalore)

Mr. Saqib Mushtaq Shah, a KAIX visiting graduate student from ISI Bangalore who will stay at KAIST for 8 weeks, is going to give a series of weekly talks on the Milnor K-theory from the beginning. It is part of his KAIX summer internship works.

2024-07-04 / 16:50 ~ 17:30

편미분방정식 통합연구실 세미나 - 편미분방정식: Thom's gradient conjecture for nonlinear evolution equations part II

by 최범준()

Following the brief introduction to Lojasiewicz's theory in the first part, in the second part we discuss Thom's gradient conjecture and our recent joint work with Pei-Ken Hung where we generalized this conjecture to the class of PDEs. The result classifies the next-order asymptotics by revealing both the rate and the direction of convergence to the limit. Finally we talk about possible future applications and working directions.

2024-07-03 / 14:00 ~ 16:00

학과 세미나/콜로퀴엄 - 기타: Introduction to complex algebraic geometry and Hodge theory #8

by 김재홍(KAIST)

This is part of an informal seminar series to be given by Mr. Jaehong Kim, who has been studying the book "Hodge theory and Complex Algebraic Geometry Vol 1 by Claire Voisin" for a few months. It will summarize about 70-80% of the book.

2024-07-02 / 16:30 ~ 17:30

IBS-KAIST 세미나 - 이산수학: Symmetric Tropical Rank 2 Matrices

by Kisun Lee(Clemson University)

Tropical geometry replaces usual addition and multiplication with tropical addition (the min) and tropical multiplication (the sum), which offers a polyhedral interpretation of algebraic variety. This talk aims to pitch the usefulness of tropical geometry in understanding classical algebraic geometry. As an example, we introduce the tropicalization of the variety of symmetric rank 2 matrices. We discuss that this tropicalization has a simplicial complex structure as the space of symmetric bicolored trees. As a result, we show that this space is shellable and delve into its matroidal structure. It is based on the joint work with May Cai and Josephine Yu.

2024-06-28 / 16:30 ~ 17:30

IBS-KAIST 세미나 - 이산수학: Skein relations for punctured surfaces

by Wonwoo Kang(University of Illinois, Urbana-Champaign)

Since the introduction of cluster algebras by Fomin and Zelevinsky in 2002, there has been significant interest in cluster algebras of surface type. These algebras are particularly noteworthy due to their ability to construct various combinatorial structures like snake graphs, T-paths, and posets, which are useful for proving key structural properties such as positivity or the existence of bases. In this talk, we will begin by presenting a cluster expansion formula that integrates the work of Musiker, Schiffler, and Williams with contributions from Wilson, utilizing poset representatives for arcs on triangulated surfaces. Using these posets and the expansion formula as tools, we will demonstrate skein relations, which resolve intersections or incompatibilities between arcs. Topologically, a skein relation replaces intersecting arcs or arcs with self-intersections with two sets of arcs that avoid the intersection differently. Additionally, we will show that all skein relations on punctured surfaces include a term that is not divisible by any coefficient variable. Consequently, we will see that the bangles and bracelets form spanning sets and exhibit linear independence. This work is done in collaboration with Esther Banaian and Elizabeth Kelley.

2024-07-04 / 16:00 ~ 16:40

편미분방정식 통합연구실 세미나 - 편미분방정식: Thom's gradient conjecture for nonlinear evolution equations part I

by 최범준()

The analysis on the limiting behavior of solution is pivotal for equations in geometric analysis, mathematical physics and application in optimization. In 80s, Rene Thom conjectured that if an analytic gradient flow has a limit, then it approaches to the limit along a unique asymptotic direction. This represents a next-order question following the seminal works by Lojasiewicz and L. Simon. In 2000, Thom's conjecture was affirmatively proved by Kurdyka, Mostowski, and Parusinski for finite dimensional gradient flows. In this first part, we will discuss about the basics about theory of Lojasiewicz concerning the uniqueness of limits. Then we explore vast applications in PDEs which were initiated by Leon Simon.

2024-06-27 / 16:00 ~ 18:00

학과 세미나/콜로퀴엄 - 위상수학 세미나:

by ()

It has been well known that any closed, orientable 3-manifold can be obtained by performing Dehn surgery on a link in S^3. One of the most prominent problems in 3-manifold topology is to list all the possible lens spaces that can be obtained by a Dehn surgery along a knot in S^3, which has been solved by Greene. A natural generalization of this problem is to list all the possible lens spaces that can be obtained by a Dehn surgery from other lens spaces. Besides, considering surgeries between lens spaces is also motivated from DNA topology. In this talk, we will discuss distance one surgeries between lens spaces L(n, 1) with n ≥ 5 odd and lens spaces L(s, 1) for nonzero s and the corresponding band surgeries from T(2, n) to T(2, s), by using our Heegaard Floer d-invariant surgery formula, which is deduced from the Heegaard Floer mappping cone formula. We give an almost complete classification of the above surgeries.

Events for the 취소된 행사 포함