Seminars and Colloquiums
for the week of January 16, 2017
Dr. Yu-Ting Chen, UTK, Tuesday
Dr. Stefan Richter, UTK, Wednesday
Liem Nguyen, NCSU, Wednesday
Oliver Thistlewaite, UTK, Thursday
TEA TIME -
3:00 pm – 3:30 pm
Monday & Tuesday
Room: Ayres 401
Hosted by: Cara Sulyok
Tuesday, January 17th
TITLE: Organizational Meeting
SPEAKER: Dr. Yu-Ting Chen, UTK
TIME: 2:10pm - 3:25pm
ROOM: Ayres 113
All faculty and graduate students are welcome.
Wednesday, January 18th
TITLE: Interpolating sequences for multiplier algebras
SPEAKER: Dr. Stefan Richter, UTK
TIME: 2:30pm - 3:20pm
ROOM: Ayres G003
Interpolating sequences for the algebra of bounded analytic functions on the open unit disc were characterized by Carleson in 1958. Marshall/Sundberg and Bishop proved an analogous theorem for the multipliers of the Dirichlet space in 1994. By use of the recent solution to the Kadison-Singer problem by Marcus, Spielman, and Srivastava we show that the theorem holds for all spaces with complete Pick kernel.
JOINT DE/ CAM SEMINAR
TITLE: Global reconstruction methods for nonlinear inverse scattering problems
SPEAKER: Liem Nguyen, NCSU
TIME: 3:35pm – 4:25pm
ROOM: Ayres 113
This talk is about numerical methods for solving inverse problems arising from wave scattering. Potential applications of these problems include non-destructive testing, detection of explosives, medical imaging, geophysical prospection and radar. The major challenges in studying the numerical solution to these inverse problems are from the fact that the problems are highly nonlinear and ill-posed. The most developed approach in literature, which is nonlinear optimization schemes, typically requires good initial guesses for the solution since the objective functionals to minimize are in general not convex. However, these good initial guesses of the solution (or strong a-priori information of the solution) are not always available in many practical applications. The latter is the main reason for us to study global reconstruction methods, which do not rely on strong a-priori information of the solution, for solving nonlinear inverse problems. I will present in this talk two kinds of global methods as well as their numerical performance. This first one aims to solve a coefficient inverse problem with single measurement and the second is for a shape inverse problem for periodic structures.
Thursday, January 19th
TITLE: Boolean Formulas, Hypergraphs, and Combinatorial Topology
SPEAKER: Oliver Thistlewaite, UTK
TIME: 3:40pm – 4:30pm
ROOM: Ayres 405
For this talk, our goal will be to study the shape of spaces of Boolean formulas. These formulas consist of variables which can be assigned TRUE or FALSE together with the logical operations AND, OR, and NOT. To do this, we will introduce a simplicial complex, called the theta complex, associated to any hypergraph. Simplicial complexes are a generalization of topological spaces one may obtain by gluing together line segments and solid triangles and a hypergraph is a generalization of a graph where an edge can connect any number of vertices.
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 colloquium AT math DOT utk DOT edu