Symplectic topology and mirror symmetry of partial flag manifolds
Soon after Gromov’s applications of pseudo-holomorphic curves to symplectic topology, Floer invented an infinite-dimensional Morse theory by analyzing moduli spaces of pseudo-holomorphic curves to make substantial progress on Arnold&r...
1. 금본위제, 달러, 비트코인 등 돈의 흐름으로 보는 세계사 2. 사람은 어떻게 생각하고 행동하는가 ? (행동경제학, 비선형성) 3. 돈에 대한 생각, 행동, 습관을 바꾸어보자. (부자들은 무엇이 다른가 ? 지금부터 준비해보자.) 4. 주식, 부동산 등 자산관리 [...
<학부생을 위한 ɛ 강연> Mathematics and music: Pythagoras, Bach, Fibonacci and AI
In this talk, I will introduce the audience to the original beauty that leads to exploring the mathematical elements in music. I will cover the following topics on the connection between music and mathematics. - Harmonics & equations - ...
Topological surgery through singularity in mean curvature flow
The mean curvature flow is an evolution of hypersurfaces satisfying a geometric heat equation. The flow naturally develops singularities and changes the topology of the hypersurfaces at singularities, Therefore, one can study topological pr...
Heavy-tailed large deviations and deep learning's generalization mystery
Abstract: While the typical behaviors of stochastic systems are often deceptively oblivious to the tail distributions of the underlying uncertainties, the ways rare events arise are vastly different depending on whether the underlying tail ...
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...
<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...
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...
For each natural number k, the C^k diffeomorphisms of the circle form a group with function compositions. This definition even extends to real numbers k no less than one by Hölder continuity. We survey algebraic properties of this grou...
<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
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...
Free boundary problems arising from mathematical finance
Many problems in financial mathematics are closely related to the stochastic optimization problem because the optimal decision must be made under the uncertainty. In particular, optimal stopping, singular control, and optimal switching prob...
Coulomb Gases are point processes consisting of particles whose pair interaction is governed by the Coulomb potential. There is also an external potential which confines the particles to a region. Wigner introduced this toy model for the Gi...
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...