Upcoming seminars

Upcoming Seminars
Mon
04/21/2014
(tomorrow)
4:00pm
Seminar: Combinatorics
What is Ramsey-equivalent to a clique?
Andrey Grinshpun, Massachusetts Institute of Technology
Contact: Dwight Duffus, dwight@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W306
Tue
04/22/2014
(in 2 days)
5:00pm
Seminar: Algebra
Rational connectivity and analytic contractibility
Tyler Foster, University of Michigan
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W302
Let K be an algebraically closed field of characteristic 0. A smooth projective K-variety X is rationally connected if each pair of points in X is connected by a rational curve inside X. Over a non-archimedean field K, each of these rational curves becomes a contractible Berkovich space, so X has lots of contractible subvarieties. In fact more is true: In this talk, I will discuss recent work with Morgan Brown in which we prove that over the non-archimedean field K=C((t)), the Berkovich space associated to any smooth projective, rationally connected variety X is contractible.
Thu
04/24/2014
(in 4 days)
4:00pm
Seminar
Truth Is Stranger Than Fiction: A Look At Some Improbabilities
Dr. Rick Durrett, Duke University
Venue: MSC E208
Probability is full of surprises and paradoxes, most of which result from doing the calculation incorrectly. We will illustrate this using some familiar old stories and new ones: the Monty Hall problem, cognitive dissonance in Monkeys, the birthday problem, lottery coincidences, the sad story of Sally Clark, the 2012 election, and Warren Buffet’s bracket challenge.
Tue
04/29/2014
(in 9 days)
4:00pm
Seminar: Algebra
Transversality defect of two lagrangians and ternary index. Application: Formulas of (non) additivity of signatures and of linking forms
Jean Barge, Ecole polytechnique
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W302
(This is a common work with Jean Lannes) To a pair of lagrangians in a symplectic space, we associate a symetric bilinear form well defined up to the addition of non-degenerate forms and which is itself non-degenerate if and only if the two lagrangians are transversal. To a triple of lagrangians, we associate a ternary index which is a raffinement of the Leray-Kashiwara index and which generalizes for any (commutative) ring the index defined by Wall for fields. We will explain how these two invariants can be used to compute signatures and linking forms of manifolds obtained by gluing.
Fri
05/02/2014
(in 12 days)
3:00pm
Seminar: Algebra
On Stabilization of Classical Groups
Rabeya Basu, IISER, Pune
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W304
The $K_1$ stabilization of general linear groups is one of the problem related to Serre's problem on projective modules. It was first studied by Bass---Milnor---Serre during mid-sixties. They showed that the surjective bound is d+1, where d is the Krull dimension of the base ring, and conjectured that the injective bound is d+2. Shortly after that it was proved by L.N. Vaserstein. Later we see analog results for other classical groups in the work of A. Suslin, V. Kopeiko, Vaserstien, A. Bak, G. Tang, V. Petrov, W. vander Kallen et al. including the recent break through work by J.Fasel, R.A. Rao and R.G. Swan. In this talk we shall discuss results on injective stabilization for a big class of classical grou
Tue
05/06/2014
(in 16 days)
4:00pm
Seminar: Algebra
Log canonical and F-pure thresholds and ordinary reduction
Lance Edward Miller, University of Arkansas
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W306
The F-pure threshold of a variety in characteristic p > 0 is a rational number which measure of its singularities near the origin. It is intimately connected to birrational invariants of complex varieties such as the log canonical threshold through reduction mod p. The agreement of these two invariants is also deeply connected to ordinary (in the sense of Bloch-Kato) reduction as can already been seen clearly in the case of elliptic curves. This talk introduces these thresholds and their connections and explores a special cases where agreement can be shown purely in using algebraic methods.
Wed
08/27/2014
(in 129 days)
4:00pm
Seminar: Algebra
Title to be announced
Frank Thorne, University of South Carolina
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Venue: Mathematics and Science Center, Room W302