## Math Calendar

Tuesday, March 26, 2019

13:15-15:00

610

16:00-17:00

HFG 611

Utrecht Geometry Center Seminar

Christoph Winges (MPIM Bonn) - Coarse homology theories and assembly maps

see description

Coarse homology theories provide an analog of homology theories which is adapted to the purposes of large-scale geometry. I will survey how they can be utilised to provide concrete models of assembly maps. As time allows, I will also explain an axiomatic framework which facilitates proofs of split-injectivity results for various assembly maps. This recovers known results eg for the algebraic K-theory of discrete group rings, but also accomodates invariants such as A-theory. Joint work with Ulrich Bunke, Alexander Engel and Daniel Kasprowski.

Thursday, March 28, 2019

16:00-17:00

Utrecht

Complex Systems Seminar

Cristian Spitoni (UU) - Nucleation for long-range Ising models, HFG 611

see description

Title: Nucleation for long-range Ising models

Abstract:

In this talk we study the metastability phenomena for a class of "long-range" Ising models. We will start with the one-dimensional case, where, under suitable general conditions, the configuration -1 is the only metastable state. Moreover, we illustrate the theory with two examples (exponentially and polynomially decaying interaction) and we show that the critical droplet can be macroscopic or mesoscopic, according to the value of the external magnetic field. Heuristics and preliminary results for the two-dimensional case will be briefly discussed as well.

Abstract:

In this talk we study the metastability phenomena for a class of "long-range" Ising models. We will start with the one-dimensional case, where, under suitable general conditions, the configuration -1 is the only metastable state. Moreover, we illustrate the theory with two examples (exponentially and polynomially decaying interaction) and we show that the critical droplet can be macroscopic or mesoscopic, according to the value of the external magnetic field. Heuristics and preliminary results for the two-dimensional case will be briefly discussed as well.

Monday, April 1, 2019

13:00-15:00

Duistermaat

13:00-15:00

HFG 610

Tuesday, April 2, 2019

16:00-17:00

HFG 611

Utrecht Geometry Center Seminar

Stefano Marseglia (Universiteit Utrecht) - Abelian varieties over finite fields isogenous to a power

see description

Abstract: Let A be an ordinary square-free abelian variety over a finite field. In this talk we will describe the category of abelian varieties isogenous to A^r in terms of R-modules, where R is an order in a certain étale algebra.

We will describe also polarizations and groups of automophisms. Under certain mild assumption on the order R, we will be able to effectively compute the abelian varieties up to isomorphism and in the case r=1 we can also list all polarizations of a fixed degree (up to polarized isomorphisms) with automorphism groups and period matrix of the canonical lift.

We will describe also polarizations and groups of automophisms. Under certain mild assumption on the order R, we will be able to effectively compute the abelian varieties up to isomorphism and in the case r=1 we can also list all polarizations of a fixed degree (up to polarized isomorphisms) with automorphism groups and period matrix of the canonical lift.

Wednesday, April 3, 2019

11:00-12:00

BBG 205

Inter-departemental Mathematical Physics Seminar

Hans Jockers (Universität Bonn) - Mirror Symmetry of Branes and the Quest of Hyperbolic 3-manifolds

see description

Abstract: "Mirror symmetry is a powerful dualitybetween type II string compactifications on a pair of mirror dual Calabi-Yaumanifolds. Apart from its relevance in determining non-perturbative correctionsto the low energy effective action and in computing enumerative invariants ofCalabi-Yau manifolds, mirror symmetry also predicts an equivalence between theset of D-brane states appearing in such a pair of mirror dual Calabi-Yaucompactifications. In this talk we review some general aspects of mirrorsymmetry on the level of D-branes. We give evidence and illustrate with anexample that for particular classes of D-branes in Calabi-Yau 3-folds thecorresponding mirror branes in the mirror geometry are associated withhyperbolic 3-manifolds.”

Monday, April 8, 2019

13:00-15:00

Duistermaat

13:00-15:00

HFG 610

Tuesday, April 9, 2019

Thursday, April 11, 2019

Monday, April 15, 2019

13:00-15:00

HFG 610

Tuesday, April 16, 2019

16:00-17:00

HFG 611

Tuesday, April 23, 2019

16:00-17:00

HFG 611

Monday, April 29, 2019

13:00-15:00

HFG 610

13:00-15:00

HFG 610

Tuesday, April 30, 2019

Thursday, May 2, 2019

16:00-17:00

Utrecht

Monday, May 6, 2019

13:00-15:00

HFG 610

Tuesday, May 7, 2019

16:00-17:00

HFG 611

Thursday, May 9, 2019

Monday, May 13, 2019

13:00-15:00

HFG 610

Tuesday, May 14, 2019

16:00-17:00

HFG 611

Monday, May 20, 2019

13:00-15:00

HFG 610

Tuesday, May 21, 2019

16:00-17:00

HFG 611

Utrecht Geometry Center Seminar

Adrien Sauvaget (UU) - Counting geodesics on flat surfaces

see description

Description:We will present a universal formula for the growth rate of geodesics between

two conical singularities of a flat surface. The proof of this formula involves

both ingredients from representation theory via the Bloch-Okounkov formalism

and from intersection theory on moduli spaces.

two conical singularities of a flat surface. The proof of this formula involves

both ingredients from representation theory via the Bloch-Okounkov formalism

and from intersection theory on moduli spaces.

Thursday, May 23, 2019

15:30-16:30

Tuesday, May 28, 2019

16:00-17:00

HFG 611

Tuesday, June 4, 2019

16:00-17:00

HFG 611

Thursday, June 6, 2019

16:00-17:00

Utrecht

Tuesday, June 11, 2019

Tuesday, June 18, 2019

16:00-17:00

HFG 611

Thursday, June 20, 2019

16:00-17:00

Utrecht

Tuesday, June 25, 2019

Tuesday, July 2, 2019

Tuesday, July 9, 2019

Tuesday, July 16, 2019

Tuesday, July 23, 2019

Tuesday, July 30, 2019

Tuesday, August 6, 2019

Tuesday, August 13, 2019

Tuesday, August 20, 2019

Tuesday, August 27, 2019

Tuesday, September 3, 2019

Tuesday, September 10, 2019

Tuesday, September 17, 2019

Tuesday, September 24, 2019