Department of Mathematics
Mathematics Colloquium
OrganizerThe Mathematics Department Colloquium typically meets on Thursdays from 12:30 pm to 1:20 pm in NAC 6/111. This will typically be preceded by tea and coffee at noon in the math lounge, and will be followed by lunch.
Upcoming talks

Thursday, March 01, 2018, 12:30PM, 
Rina Foygel Barber (University of Chicago), 

Thursday, March 15, 2018, 12:30PM, 
Keith Burns (Northwestern University), 

Thursday, March 22, 2018, 12:30PM, 
Katherine Kinnaird (Brown University ), 

Thursday, March 29, 2018, 12:30PM, 
Rasul Shafikov (University of Western Ontario), 

Thursday, April 19, 2018, 12:30PM, 
Gwen Spencer (Smith College), 

Thursday, May 10, 2018, 12:30PM, 
Angela Hicks (Lehigh University), 
Most recent talks

Thursday, December 07, 2017, 12:30PM, NAC 6/111
Peter Winkler (Dartmouth College), The Puzzle that Spawned 100 Philosophy PapersProposed 17 years ago by philosopher Adam Elga, "Sleeping Beauty" seems to be a simple question about probability. Is it? If so, Why does it incite such passion? We'll describe the various "camps" in the controversy, and attack or defend their arguments. In the end, you'll have to decide for yourself where you stand!

Thursday, November 16, 2017, 12:30PM, NAC 6/111
Dave Constantine (Wesleyan University), Symbolic codings for geodesic flows in negative curvatureThe geodesic flow on a compact manifold provides a dynamical tool with which to study the geometry of the manifold. In negative curvature, the properties of this flow are particularly nice  it has dense orbits but also many closed orbits, is ergodic and mixing for Liouville measure, and so on. However, proving more delicate properties of this flow via its geometric description can be difficult. Symbolic codings for the flow are enormously helpful in this respect, removing the dynamics from the world of Riemannian metrics, tangent vectors and Jacobi fields and recasting them in the language of shift spaces where things are far more concrete and detailed computations are possible. This idea goes back to work of Hedlund and finds its best expression in the work of Bowen, who produced Markov codings for geodesic flows in negative curvature.
In this talk I'll give an overview of the symbolic codings approach to this problem, and try to indicate its usefulness. Then I'll present some recent work with Lafont and Thompson on Markov codings for geodesic flows on CAT(1) metric spaces. This work extends all of the good dynamical properties of the Riemannian negativelycurved setting to nonsmooth metric settings and shows how a very simple but strong metric geometry property lies behind the dynamical regularity that geodesic flows exhibit.

Thursday, November 09, 2017, 12:30PM, NAC 6/111
Mrinal Kanti Roychowdhury (The University of Texas Rio Grande Valley), Optimal QuantizationThe basic goal of quantization for probability distribution is to reduce the number of values, which is typically uncountable, describing a probability distribution to some finite set and thus approximation of a continuous probability distribution by a discrete distribution. Though the term 'quantization' is known to electrical engineers for the last several decades, it is still a new area of research to the mathematical community. In my presentation, first I will give the basic definitions that one needs to know to work in this area. Then, I will give some examples, and talk about the quantization on mixed distributions. Mixed distributions are an exciting new area for optimal quantization. I will also tell some open problems relating to mixed distributions