If you want to receive e-mail announcements of talks please contact
Antoine Mellet (mellet@math.umd.edu), or
Dionisios Margetis (dio@math.umd.edu).
|
January 29
|
NO SEMINAR
|
|
Abstract:
|
|
February 5
|
The interaction between nonlinear Koiter shells and viscous fluids
Arthur Cheng
CSCAMM and Department of Mathematics -- UMCP
|
|
Abstract:
|
|
February 12
|
An invariance principle for random traveling waves in one dimension
James Nolen
Department of Mathematics --
Duke University
|
|
Abstract:
Some reaction-diffusion equations admit traveling wave
solutions, which are simple models of a chemical reaction spreading with
constant speed. Even in a heterogeneous medium, solutions to the initial
value problem may develop an interface propagating with a well-defined
asymptotic speed. I will describe an invariance principle for the random
interface that develops in the solution of a reaction diffusion equation
in a random medium. I will discuss the connection between this limit
theorem and recent work on stability of generalized traveling waves.
|
|
February 19
|
RESERVED FOR THE N. WIENER CTR FOURIER TALKS
|
|
|
February 26
JOINT PDE/NUMERICAL ANALYSIS SEMINAR
|
A Singularly Perturbed Semilinear Reaction-Diffusion Problem in a Polygonal Domain
Bruce Kellogg
Mathematics and IPST, UMCP
|
Abstract:
The semilinear reaction-diffusion equation
-epsilon^2 Del^2 u + b(x,u)=0
with Dirichlet boundary conditions is considered in a convex polygonal
domain. The diffusion parameter epsilon^2 is arbitrarily small, and the "reduced equation" b(x,u_0(x))=0 may have multiple solutions. An asymptotic expansion for u is constructed that involves boundary and corner layer functions. By perturbing this asymptotic expansion, we obtain certain sub- and super-solutions and thus show the existence of a solution u that is close to the constructed asymptotic expansion. The polygonal boundary forces the study of the nonlinear autonomous elliptic equation -Del^2 z+f(z)=0 posed in an infinite sector, and the well-posedness of the corresponding linearized problem. The arguments that lead to this well-posedness may have an independent interest.
The material in the talk is joint work with N. Kopteva (Limerick, Ireland).
|
|
March 5
|
NO SEMINAR -- CSCAMM Kinetic FRG Young Researchers Workshop
March 2-5, 2009
|
|
Abstract:
|
|
March 12
|
Reaction-Diffusion Equations with Nonlinear Boundary Conditions in Narrow
Domains and Wave Front Propagation
Konstantinos Spiliopoulos
Department of Mathematics -- UMCP
|
|
Abstract:
We will consider the second initial boundary problem in narrow
domains of width $\epsilon\ll 1$ for linear second order
differential equations with nonlinear boundary conditions. Using
probabilistic methods we show that the solution of such a problem
converges as $\epsilon \downarrow 0$ to the solution of a standard
reaction-diffusion equation in a domain of reduced dimension. This
reduction allows to obtain some results concerning wave front
propagation in narrow domains. In particular, we describe conditions
leading to jumps of the wave front. In addition, an important and
interesting problem, which is related to the previous one, is the Wiener
process with instantaneous reflection in a narrow tube which, in contrast
to before, is assumed to be non-smooth asymptotically.
|
|
March 19
|
SPRING BREAK -- NO SEMINAR
|
|
|
|
March 26
|
RESERVED FOR WORKSHOP
|
|
|
|
April 2
|
Traveling fronts in disordered media
Andrej Zlatos
Department of Mathematics --
University of Chicago
|
|
Abstract:
We study generalized traveling front solutions of reaction-diffusion equations modeling flame propagation in combustible media. Although the case of periodic media has been studied extensively, until very recently little has been known for general disordered media. In this talk we will address questions of existence, uniqueness, and stability of traveling fronts in this framework.
|
|
April 9
|
No Seminar
|
|
Abstract:
|
|
April 16
|
The inviscid limit in the plane for nondecaying vorticity
Elaine Cozzi
Department of Mathematics - Carnegie Mellon University
|
|
Abstract: We consider solutions of the Navier-Stokes and Euler equations in the plane with bounded, nondecaying initial vorticity. Specifically, we assume that initial velocity has finite energy, and we show that as viscosity approaches zero, the solutions of the Navier-Stokes equations converge to the solution of the Euler equations uniformly in space, where convergence holds for any finite time. We also study the case where initial velocity is merely bounded and establish a similar short time result.
|
April 23
|
Round droplet solutions and oval droplet solutions for the
Ohta-Kawasaki theory and the Gierer-Meinhardt theory
Xiaofeng Ren
Department of Mathematics -- Georges Washington University
CANCELLED
|
|
Abstract:
|
April 30
JOINT APPL.
MATH/NUMERICAL ANALYSIS SEM.
-- AZIZ LECTURER
|
A New Formalism for Electromagnetic Scattering in Complex Geometry
Leslie Greengard
Courant Institute of Mathematical Sciences
New York University
|
|
Abstract:
We will describe some recent, elementary results in the theory of
electromagnetic scattering. There are two classical approaches that we will
review - one based on the vector and scalar potential and applicable in
arbitrary geometry, and one based on two scalar potentials (due to Lorenz,
Debye and Mie), valid only in the exterior of a sphere. In trying to extend the
Lorenz-Debye-Mie approach to arbitrary geometry, we have encountered some new
mathematical questions involving differential geometry, partial differential
equations and numerical analysis. This is joint work with Charlie Epstein.
|
|
May 7
|
OPEN
|
|
Abstract:
|
|
May 14
|
OPEN
|
|
Abstract:
|
Special accomodations for individuals with disabilities can be made
by calling in advance (301) 405-5048. It would be appreciated if we are
notified at least one week in advance.
