A W-algebra is introduced as a symmetry algebra in 2-dimensional conformal field theory. Mathematical realization of a W-algebra was introduced by the theory of vertex algebras. Especially, W-algebras related to Lie superalgebras have been s...
<학부생을 위한 ɛ 강연> Geometry and algebra of computational complexity
학부생을 위한 이 강연에서는 고전적 튜링 기계의 기본적 정의로부터 시작하여 • 튜링기계를 비롯한 다양한 컴퓨터 모델의 복잡도 개념; • 계산(불)가능성 – 특히 디오판틴 방정식의 알고리즘적 해결법 (힐버트의 10번째 문제); • Non-deterministic 튜링 기계...
Ill-posedness for incompressible Euler equations at critical regularit
We obtain a quantitative and robust proof that incompressible fluid models are strongly ill-posed in critical Sobolev spaces, in the sense that norm inflation and even nonexistence occur for critical initial data. We then show how to use th...
WGAN with an Infinitely wide generator has no spurious stationary points
Generative adversarial networks (GAN) are a widely used class of deep generative models, but their minimax training dynamics are not understood very well. In this work, we show that GANs with a 2-layer infinite-width generator and a 2-layer...
<학부생을 위한 ɛ 강연> Symplectic geometry and the three-body problem
We describe some of the history of the three-body problem and how it lead to symplectic geometry. We start by sketching Poincare’s prize-winning work, and discuss how it lead to the birth of the fields of dynamical systems and symplec...
CategoryMath ColloquiaDept.서울대학교LecturerOtto van Koert
<정년퇴임 기념강연> Hardy, Beurling, and invariant subspaces
The invariant subspace problem is one of the longstanding open problem in the field of functional analysis and operator theory. It is due to J. von Neumann (in 1932) and is stated as: Does every operator have a nontrivial invariant subspace...
Diophantine equations and moduli spaces with nonlinear symmetry
A fundamental result in number theory is that, under certain linear actions of arithmetic groups on homogeneous varieties, the integral points of the varieties decompose into finitely many orbits. For a classical example, the set of integra...
Sufficient conditions for the Jensen polynomials of the derivatives of a real entire function to be hyperbolic are obtained. The conditions are given in terms of the growth rate and zero distribution of the function. As a consequence some r...
초록: Let X be a homogeneous space for a Lie group G. A (G,X)-structure on a manifold M is an atlas of coordinate charts valued in X, such that the changes of coordinates locally lie in G. It is a fundamental question to ask how many ways o...
Geometric Langlands theory: A bridge between number theory and physics
※ 강연 앞 부분이 잘렸습니다. (강연자료 다운: Geometric Langlands Theory [A Bridge between Number Theory and Physics] (2022.04.28).pdf ) 초록: The Langlands program consists of a tantalizing collection of surprising results and conjectures w...
<2020년도 젊은 과학자상 수상 기념강연> Metastability of stochastic systems
Metastability란 random process가 여러 개의 안정된 상태를 가질 때 반드시 나타나는 현상으로, 수리물리학이나 화학의 여러 모형들은 물론 딥러닝의 알고리즘 등 다양한 곳에서 공통적으로 나타나는 현상이다. 본 강연에서는 이 Metastability를 수학적으로...
작용수대수에서 순서구조가 중요한 역할을 한다. C*-대수의 시작이라 할 수 있는 Gelfand-Naimark-Segal 표현정리는 양선형범함수로부터 *-준동형을 만들어내는데, 그 표현정리 이후 여러 가지 종류의 양사상에 대한 연구가 이루어졌다. 최근 활발하게 연구되...
This talk concerns maximal functions given by averages over some family of geometric objects. I will discuss the boundedness of those maximal functions on the Lebesgue spaces and its role in problems of harmonic analysis.
There have been at least two surprising events to geometers in 80-90s that they had to admit physics really helps to solve classical problems in geometry. Donaldson proved the existence of exotic 4-dimensional Euclidean space using gauge th...
On classification of long-term dynamics for some critical PDEs
This talk concerns the problem of classifying long-term dynamics for critical evolutionary PDEs. I will first discuss what the critical PDEs are and soliton resolution for these equations. Building upon soliton resolution, I will further in...
Homogeneous dynamics and its application to number theory
Homogeneous dynamics, the theory of flows on homogeneous spaces, has been proved useful for certain problems in Number theory. In this talk, we will explain what kind of geometry and dynamics we need to solve certain number theoretic questi...
The thirteen books "Elements" were written or collected by Euclid of Alexandria about 300 BCE. Many think that "Elements" is the most important example of deductive mathematics. In fact, the Common Notions and the Postulates of Elements are...
Mechanization of proof: from 4-Color theorem to compiler verification
I will give a broad introduction to how to mechanize mathematics (or proof), which will be mainly about the proof assistant Coq. Mechanizing mathematics consists of (i) defining a set theory, (2) developing a tool that allows writing definit...
