Upcoming seminars

Upcoming Seminars
Tue
02/03/2015
(in 4 days)
4:00pm
Colloquium: Number Theory
Umbral Moonshine
John Duncan, Case Western Reserve University
Contact: David Borthwick, davidb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W303
Umbral moonshine is a new and rapidly developing field at the intersection of number theory, group theory and mathematical physics. I will introduce the subject, describe its main challenges, and present some recent progress, including joint work with Michael Griffin and Ken Ono.
Thu
02/05/2015
(in 6 days)
4:00pm
Colloquium: Number Theory
Pencils of quadrics and the arithmetic of hyperelliptic curves
Jerry Wang, Princeton University
Contact: David Borthwick, davidb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W303
Finding integral and rational solutions to polynomial equations with integer coefficients has always been a fascinating subject to mathematicians. In this talk we will look at the hyperelliptic equations y^2 = f(x) and discuss how many solutions they have typically. There has been several results on this recently by Manjul Bhargava and his collaborators via the study of rational orbits of certain representations of reductive groups and by applying the techniques of geometry of numbers to count these orbits. We will discuss our recent joint work with Manjul Bhargava and Benedict Gross on solutions to the hyperelliptic equations over odd degree field extensions of Q and see how the geometry of pencils of quadrics plays a pivotal role in this work.
Tue
02/17/2015
(in 18 days)
4:00pm
Seminar: Computer Science
Looking for Structure in Real-World Networks
Blair Sullivan, Department of Computer Science North Carolina State University
Contact: Michele Benzi, benzi@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W306
Graphs offer a natural representation of relationships within data -- for example, edges can be defined based on any user-defined measure of similarity (e.g. word frequencies, geographic proximity of observation, gene expression levels, or overlap in sample populations) or interaction (e.g. social friendship, communication, chemical bonds/protein bindings, or migration). As such, network analysis is playing an increasingly important role in understanding the data collected in a wide variety of social, scientific, and engineering settings. Unfortunately, efficient graph algorithms with guaranteed performance and solution quality are impossible in general networks (according to computational complexity).\\ \\ One tantalizing approach to increasing scalability without sacrificing accuracy is to employ a suite of powerful (parameterized) algorithms developed by the theoretical computer science community which exploit specific forms of sparse graph structure to drastically reduce running time. The applicability of these algorithms, however, is unclear, since the (extensive) research effort in network science to characterize the structure of real-world graphs has been primarily focused on either coarse, global properties (e.g., diameter) or very localized measurements (e.g., clustering coefficient) -- metrics which are insufficient for ensuring efficient algorithms.\\ \\ We discuss recent work on bridging the gap between network analysis and structural graph algorithms, answering questions like: Do real-world networks exhibit structural properties that enable efficient algorithms? Is it observable empirically? Can sparse structure be proven for popular random graph models? How does such a framework help? Are the efficient algorithms associated with this structure relevant for common tasks such as evaluating communities, clustering and motifs? Can we reduce the (often super-exponential) dependence of these approaches on their structural parameters? Joint work with E. Demaine, M. Farrell, T. Goodrich, N. Lemons, F. Reidl, P. Rossmanith, F. Sanchez Villaamil and S. Sikdar.
Thu
02/26/2015
(in 27 days)
4:00pm
Seminar: Algebra
Title to be announced
Satya Mandal, University of Kansas
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W304
Tue
03/03/2015
(in 32 days)
4:00pm
Seminar: Algebra
Title to be announced
Jean-Louis Colliot-Thelene, Universite Paris-Sud
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W304
Tue
03/17/2015
(in 46 days)
4:00pm
Seminar: Algebra
Title to be announced
Larry Rolen, University of Cologne
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W304