Geometric Analysis and PDE Seminar

2013. 12. 23. 11:00-12:30   Room 1424         Ohsang Kwon (Center for PDE, East China Normal University)
The effects of starvation driven diffusion on the dynamics of populations

Ohsang Kwon (Center for PDE, East China Normal University)
The effects of starvation driven diffusion on the dynamics of populations

ABSTRACT. The dispersal strategies of biological organisms are key ingredients in their ecological evolution. It is well-accepted that spatial and temporal heterogeneities of environments occur in all scales and such heterogeneities play a key role in the evolutional selection of dispersal rates. Recently, starvation driven diffusion has been introduced by Cho and Kim (Bull. Math. Biol., 75 (2013) 845-870), which is a random dispersal strategy with a motility increase on starvation. In this talk, we will discuss properties of the single species model and 2 2 competition model with starvation driven diffusion, including the global asymptotic stability and the acquisition of the ideal free distribution. We show that such a dispersal strategy has fitness property and that the evolutional selection favors fitness but not simply slowness. This is the joint work with Y.-J. Kim and F. Li.

2013. 11. 08. 10:30-12:30   Room 1424         Soojung Kim (NIMS)
Harnack inequality for nondivergent parabolic operators on Riemannian manifolds

Soojung Kim (NIMS)
Harnack inequality for nondivergent parabolic operators on Riemannian manifolds

ABSTRACT. In this talk, I will discuss the Krylov-Safonov theory which is the analogue of the De Giorgi-Nash-Moser theory. In particular, I will explain the Krylov-Safonov Harnack inequality for parabolic operators on certain Riemannian manifolds. This result gives a new nondivergent proof for the Li-Yau Harnack inequality of the heat equation on manifolds with nonnegative Ricci curvature. This talk is based on a joint work with Seick Kim and Ki-Ahm Lee.

2013. 10. 11. 13:30-15:30   Room 1424         Seunghyeok Kim (KAIST)
Introduction to Lyapunov-Schmidt reduction method and its applications to various problems.

Seunghyeok Kim (KAIST)
Introduction to Lyapunov-Schmidt reduction method and its applications to various problems.

ABSTRACT. Since the seminal work of Floer and Weinstein in 1986, the Lyapunov-Schmidt reduction method has served as one of the powerful method to construct various type of solutions for equations arising mainly from physics and geometry, which leads a plethora of striking results. Throughout the talk, I will introduce the main idea of the reduction method and its applications to nonlinear Schrödinger equations, Allen-Cahn equations and so on.

2013. 10. 11. 11:00-12:00   Room 1424         Jinmyoung Seok (KIAS)
Equivalence of the Chern-Simons-Schrodinger equations and its first order self-dual systems

Jinmyoung Seok (KIAS)
Equivalence of the Chern-Simons-Schrodinger equations and its first order self-dual systems

ABSTRACT. The aim of this talk is to give a rigorous proof of the equivalence of the second order CSS equations to its first order self-dual systems when a coupling constant is critical.

2013. 09. 05. 11:00-12:00   Room 1423         Juhi Jang (University of California, Riverside)
Stability theory of polytropic gaseous stars

Juhi Jang (University of California, Riverside)
Stability theory of polytropic gaseous stars

ABSTRACT. I'll discuss stability theory of Lane-Emden equilibrium stars under Euler-Poisson or Navier-Stokes-Poisson system. A linear stability can be characterized by the adiabatic exponent. A nonlinear instability will be also discussed.


        For the talks from Sep 2012 to Aug 2013, see the link here.

TOPICS   Differential Geometry   -   Geometric Analysis   -   PDE
ORGANIZERS   Hyunsuk KANG   -   Korea Institute for Advanced Study
  Youngju KIM   -   Korea Institute for Advanced Study
  Hojoo LEE   -   Korea Institute for Advanced Study
  Leobardo ROSALES   -   Korea Institute for Advanced Study
  Jinmyoung SEOK   -   Korea Institute for Advanced Study
  Keomkyo SEO   -   Sookmyung Women's Univ.
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