Seminars and Colloquiums
for the week of September 21, 2009
Speaker:
Professor Xiaobing Feng, Monday
Dr. Yaozhong Hu, Monday
Dr. Sharon Bewick, Tuesday
Mr. Chris Sass, Wednesday
Mr. Jared Bunn, Wednesday
Mr. Ryan Clark, Wednesday
Associate Professor Alex Freire, Wednesday
Assistant Professor Steve Wise, Friday
Monday, September 21
COMPUTATIONAL/APPLIED MATH AND DE SEMINAR
TIME: 3:35 – 4:25 p.m.
ROOM: Haslam Business Bldg. 112
SPEAKER: Professor Xiaobing Feng
TITLE: “Novel Numerical Methods for High Frequency Wave Computation”
PROBABILITY SEMINAR
TIME: 3:35 – 4:25 P.M.
ROOM: Haslam Business Bldg 132
SPEAKER: Dr. Yaozhong Hu
TITLE: “Stochastic Heat Equation Driven by Fractional Noise and Local Time”
ABSTRACT: This is a joint work with David Nualart. We study the $d$-dimensional stochastic heat equation with a multiplicative Gaussian noise which is white in space and has the covariance of a fractional Brownian motion with Hurst parameter $H\in (0,1)$ in time. Two types of equations are considered. First we consider the equation in the It0-Skorohod sense, and later in the Stratonovich sense. An explicit chaos development for the solution is obtained. On the other hand, the moments of the solution are expressed in terms of the exponential moments of some weighted intersection local time of the Brownian motion. The recent work on Feynman-Kac formula of similar equations with David Nualart and Jian Song will also briefly mentioned.
Tuesday, September 22
MATH ECOLOGY SEMINAR
TIME: 9:00 – 9:50 A.M.
ROOM: NIMBioS large conference room, White Ave.
SPEAKER: Dr. Sharon Bewick
TITLE: “Characteristics of the Discrete Reaction-Diffusion Model”
Wednesday, September 23
COARSE GEOMETRY SEMINAR
TIME: 11:15 – 12:05 p.m.
ROOM: HBB 112
SPEAKER: Mr. Jared Bunn
TITLE: "Other Characterizations of Property A II"
ABSTRACT: We discuss some equivalent definitions of Yu's Property A for discrete metric spaces of bounded geometry. We are particularly interested in the characterization given by Nigel Higson and John Roe. We will also discuss Property A in terms of partitions of unity. This definition is similar to the one by Roe and Higson, but is a bit easier to understand for topologists. The main source of the proofs of equivalence comes from an expository paper by Rufus Willett
ALGEBRA SEMINAR
TIME: 2:30 – 3:20 P.M.
ROOM: Temple 303
SPEAKER: Mr. Ryan Clark
TITLE: “Stone’s representation theorem for Boolean Algebras”
ANALYSIS SEMINAR
TIME: 3:55 – 4:30 p.m.
ROOM: AC 113
SPEAKER: Mr. Chris Sass
TITLE: "Circle Packing in the Context of Projective Structures on
Riemann Surfaces"
GEOMETRIC ANALYSIS SEMINAR (Optimal Transportation)
TIME: 4:30 – 5:30 p.m.
ROOM: Haslam Business Bldg 102
SPEAKER: Associate Professor Alex Freire
TITLE: “Brenier's theorem on rearrangements of vector-valued functions” (Part 2)
(Chapter 3 of Villani's 2003 textbook)
Friday, September 25
COLLOQUIUM
TIME: 3:35 – 4:35 p.m.
ROOM: Haslam Business Bldg 102
SPEAKER: Assistant Professor Steve Wise
TITLE: “Numerical Methods for some Bistable Gradient Systems”
ABSTRACT: I will discuss a very general class of bistable gradient PDE's, giving some well know examples, including the Allen-Cahn and Cahn-Hilliard equations, as motivation. I will then touch upon the main difficulties associated with solving such equations numerically, including issues of efficiency, stability, solvability, and convergence. I present a relatively simple nonlinear numerical scheme based on first order convex splittings. I show how the idea can be generalized to obtain second-order convex splitting schemes. In both cases I demonstrate that solutions to schemes can be efficiently obtained using nonlinear multigrid methods. I will give applications of the schemes in problems of tumor growth, two-phase flow, crystal growth, and domain coarsening.
If you are interested in giving or arranging a talk for one of our seminars or colloquiums, please review our calendar.
If you have questions, or a date you would like to confirm, please contact Dr. Steve Wise.
Week of:
Past notices:
Seminars from 2008-2009 academic year
Seminars from 2007-2008 academic year
Seminars from 2006-2007 academic year