## Math Calendar

Monday, February 26, 2018

15:00-17:00

HFG 610

Tuesday, February 27, 2018

13:15-15:00

HFG 610

16:00-17:00

HFG 611

Utrecht Geometry Center Seminar

Arne Smeets (Radboud Universiteit Nijmegen) - On the diophantine complexity of p-adic fields

see description

Abstract

There are various notions of the diophantine 'complexity' or 'dimension' of a given field. Given any such notion, algebraically closed fields are the simplest ones. At the next level, one usually finds the finite fields and their 'neighbours'. Yet another step up in complexity, the so-called p-adic fields come into the picture.

I will discuss the properties of p-adic fields from the point of view of one particular notion of diophantine complexity, introduced by Serge Lang in the sixties. This will lead us to the theory of polynomial equations in 'many' variables, the celebrated Ax-Kochen theorem and some model theory.

Next, I will discuss a recent improvement to the Ax-Kochen theorem obtained in joint work by Dan Loughran, Alexei Skorobogatov and the speaker. Our approach to the problem makes heavy use of birational and toroidal geometry, and builds on work of Colliot-Thélène and Denef.

There are various notions of the diophantine 'complexity' or 'dimension' of a given field. Given any such notion, algebraically closed fields are the simplest ones. At the next level, one usually finds the finite fields and their 'neighbours'. Yet another step up in complexity, the so-called p-adic fields come into the picture.

I will discuss the properties of p-adic fields from the point of view of one particular notion of diophantine complexity, introduced by Serge Lang in the sixties. This will lead us to the theory of polynomial equations in 'many' variables, the celebrated Ax-Kochen theorem and some model theory.

Next, I will discuss a recent improvement to the Ax-Kochen theorem obtained in joint work by Dan Loughran, Alexei Skorobogatov and the speaker. Our approach to the problem makes heavy use of birational and toroidal geometry, and builds on work of Colliot-Thélène and Denef.

Thursday, March 1, 2018

15:30-16:30

KBG Cosmos

Monday, March 5, 2018

15:00-17:00

HFG 610

Tuesday, March 6, 2018

16:00-17:00

HFG 611

Utrecht Geometry Center Seminar

Jenya Sapir (MPIM Bonn/SUNY - Binghamton) - Tessellations from long geodesics on surfaces

see description

Abstract: I will talk about a recent result of Athreya, Lalley, Wroten and myself. Given a hyperbolic surface S, a typical long geodesic arc will divide the surface into many polygons. We give statistics for the geometry of a typical tessellation. Along the way, we look at how very long geodesic arcs behave in very small balls on the surface.

Wednesday, March 7, 2018

11:00-12:00

HFG 610

Thursday, March 8, 2018

14:00-15:00

HFG 610

Monday, March 12, 2018

15:00-17:00

HFG 610

Tuesday, March 13, 2018

16:00-17:00

HFG 611

Thursday, March 15, 2018

16:00-17:00

HFG 610

16:00-17:00

HFG 611

Friday, March 16, 2018

09:00-17:00

13:30-14:30

BBG 161

15:00-15:45

BBG 161

16:00-16:45

BBG 161

Monday, March 19, 2018

15:00-17:00

HFG 610

Tuesday, March 20, 2018

16:00-17:00

HFG 611

Thursday, March 22, 2018

15:30-16:30

KBG Atlas

Friday, March 23, 2018

13:15-14:15

Monday, March 26, 2018

Tuesday, March 27, 2018

16:00-17:00

HFG 611

Monday, April 2, 2018

Tuesday, April 3, 2018

Monday, April 9, 2018

Tuesday, April 10, 2018

16:00-17:00

HFG 611

Monday, April 16, 2018

Tuesday, April 17, 2018

16:00-17:00

HFG 611

Monday, April 23, 2018

Tuesday, April 24, 2018

16:00-17:00

HFG 611

Monday, April 30, 2018

Tuesday, May 1, 2018

Monday, May 7, 2018

Tuesday, May 8, 2018

Monday, May 14, 2018

Tuesday, May 15, 2018

Thursday, May 17, 2018

16:00-17:00

HFG 611

Monday, May 21, 2018

Tuesday, May 22, 2018

Monday, May 28, 2018

Tuesday, May 29, 2018

Monday, June 4, 2018

Tuesday, June 5, 2018

16:00-17:00

HFG 611

Monday, June 11, 2018

Tuesday, June 12, 2018

Thursday, June 14, 2018

15:30-16:30

Ruppert ROOD

Monday, June 18, 2018

Tuesday, June 19, 2018

Monday, June 25, 2018

Tuesday, June 26, 2018

16:00-17:00

HFG 611

Tuesday, July 3, 2018

Tuesday, July 10, 2018

Tuesday, July 17, 2018

Tuesday, July 24, 2018

Tuesday, July 31, 2018

Tuesday, August 7, 2018

Tuesday, August 14, 2018

Tuesday, August 21, 2018