Upcoming seminars

Upcoming Seminars
Wed
09/28/2016
(in 3 days)
4:00pm
Seminar: Combinatorics
Decomposing the Complete r-Graph
Imre Leader, The University of Cambridge
Contact: Dwight Duffus, dwight@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W301
The Graham-Pollak theorem states that, if we wish to decompose the complete graph Kn into complete bipartite subgraphs, then we need at least n-1 of them. What happens for hypergraphs? In other words, if we wish to decompose the complete r-graph on n vertices into complete r-partite r-graphs, how many do we need? In this talk we report on recent progress on this question. This is joint work with Luka Milicevic and Ta Sheng Tan.
Tue
10/04/2016
(in 9 days)
4:00pm
Seminar: Algebra
Bounding torsion in geometric families of abelian varieties
Ben Bakker, UGA
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W306
A celebrated theorem of Mazur asserts that the order of the torsion part of the group of rational points of an elliptic curve over Q is absolutely bounded; it is conjectured that the same is true for abelian varieties over number fields K, though very little progress has been made in proving it. The natural geometric analog where K is replaced by the function field of a complex curve---known as the geometric torsion conjecture---is equivalent to the nonexistence of low genus curves in congruence towers of Siegel modular varieties. In joint work with J. Tsimerman, we prove the conjecture for abelian varieties with real multiplication. We'll discuss a general method for bounding the genus of curves in locally symmetric varieties using hyperbolic geometry to bound Seshadri constants and apply it to some related problems.
Thu
10/06/2016
(in 11 days)
4:00pm
Seminar: General interest for MathCS and Radiology
Mathematical models for the correspondence problem
Jan Modersitzki, University of Lubeck
Contact: Lars Ruthotto, lruthotto@emory.edu
Venue: Mathematics and Science Center, Room W201
We introduce the fascinating correspondence problem also known as image registration. Roughly spoken, the goal is to automatically establish correspondences between points in different projections of a scene. In particular, in medical imaging, this problem is very important and used for applications such as motion correction or data fusion. Several examples displaying different facets of the problem are discussed. A mathematical framework for the correspondence problem is outlined. Starting point is a variational formulation, where a joint energy is to be minimized on an appropriate set. Modular building blocks such as distance measures and regularizers are briefly discussed and related to particular applications. Finally, a brief outlook on constrained image registration is presented. Constraints are used to improve the modeling by restricting the admissible set in a smart way.
Tue
10/18/2016
(in 23 days)
4:00pm
Seminar: Algebra
Athens-Atlanta Joint Number Theory Seminar
Florian Pop and Ben Bakker, UPenn and UGA
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: AT UGA
AT UGA
Mon
10/24/2016
(in 29 days)
4:00pm
Seminar: Combinatorics
A Ramsey Class of Steiner Systems
Christian Reiher, The University of Hamburg
Contact: Dwight Duffus, dwight@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W301
We construct a Ramsey class whose objects are Steiner systems. In contrast to the situation with general r-uniform hypergraphs, it turns out that simply putting linear orders on their sets of vertices is not enough for this purpose: we also have to strengthen the notion of subobjects used from induced subsystems to something we call strongly induced subsystems. Moreover we study the Ramsey properties of other classes of Steiner systems obtained from this class by either forgetting the order or by working with the usual notion of subsystems. This leads to a perhaps surprising induced Ramsey theorem in which it designs get coloured. This is joint work with Vindya Bhat, Jaroslav Nevsetvril, and Vojtvech Rodl.
Tue
11/01/2016
(in 37 days)
4:00pm
Seminar: Algebra
Conductors and minimal discriminants of hyperelliptic curves with rational Weierstrass points
Padmavathi Srinivasan, Georgia Institute of Technology
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W306
Conductors and minimal discriminants are two measures of degeneracy of the singular fiber in a family of hyperelliptic curves. In the case of elliptic curves, the Ogg-Saito formula shows that (the negative of) the Artin conductor equals the minimal discriminant. In the case of genus two curves, equality no longer holds in general, but the two invariants are related by an inequality. We investigate the relation between these two invariants for hyperelliptic curves of arbitrary genus.
Tue
11/08/2016
(in 44 days)
4:00pm
Seminar: Algebra
Title to be announced
Luca Candelori, Louisiana State University
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W306
Tue
11/15/2016
(in 51 days)
4:00pm
Seminar: Algebra
Title to be announced
Joeseph Gunther, CUNY
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W306
Tue
11/29/2016
(in 65 days)
4:00pm
Seminar: Algebra
Title to be announced
Jeff Harvey, University of Chicago
Contact: John Duncan, john.duncan@emory.edu
Venue: Mathematics and Science Center, Room W306
Tue
01/10/2017
(in 107 days)
4:00pm
Seminar: Algebra
Title to be announced
Lillian Pierce, Duke
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W306
Thu
01/12/2017
(in 109 days)
4:00pm
Colloquium: Algebra
Title to be announced
Chelsea Walton, Temple University
Contact: Victoria Powers, vicki@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W304
TBA