Math Calendar

Monday, January 21, 2019
10:00-11:00
BBG 0.05
Master thesis
Han Tiesinga - Noether's problem and the existence of generic polynomials

Abstract:

The main topics of this thesis areNoether's problem and the existence of generic polynomials. These problems areboth related to the inverse Galois problem, which asks the question whetherevery finite group is isomorphic to the Galois group of a Galois extension overthe rational numbers. We solved Noether's problem and found generic polynomialsfor the subgroups of Sn for n < 4 and the quaternion group of order 8.Moreover, we established generic polyomials for the cyclic and dihedral groupsof odd order and discussed their existence for some other groups such asp-groups and Frobenius groups. We also worked out a counterexample forNoether's problem, namely the cyclic group of order 8. 

Tuesday, January 22, 2019
15:00-17:00
Ria's Good Bye Tea in our library
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Erik van den Ban (Utrecht) - Fourier inversion for Whittaker functions on a real semisimple Lie group
In the talk we will outline a new approach to the Fourier analysis of Whittaker functions
on a real semisimple Lie group. This approach leads to both an inversion theorem
and a Paley-Wiener theorem. No specific expertise in the theory of
real semisimple Lie groups will be assumed.
Everything will be explained in the context of the simplest example SL(2,R).
Thursday, January 24, 2019
14:00-15:00
BBG 3.08
Master thesis
Robert Silfhout - Automated Geometry Theorem Proving, using algebraic geometry

Abstract:

 

Automated Geometry Theorem Proving(AGTP) is an algebraic approach to (dis)proving geometric statements in such away that it can be (mostly) fully automated. The main idea is to translatethe given geometric properties to polynomials, where the variables are thecoordinates of the given points, and look at the corresponding variety. One way(a first approach) to see if a certain property holds, is to see if itscorresponding polynomial is contained in the vanishing ideal of the initialvariety. A more complete approach is Wu's Method, which relies on the theorembehind ascending chains and pseudo-remainders.

To try out how far we can automatethis approach, I have implemented the concept of AGTP in Python.

Tuesday, January 29, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Steffen Müller (Universiteit Groningen) - Quadratic Chabauty and the split Cartan modular curve of level 13
Abstract: I will discuss a method to compute the rational points on a curve over the rationals whose Jacobian has Mordell-Weil rank equal to
the genus of the curve, and which satisfies some additional conditions. This extends the method of Chabauty-Coleman by making certain aspects of Kim's non-abelian Chabauty program explicit for such curves using p-adic heights. I will then present an application of this technique to the split (and non-split) Cartan modular curve of level 13; this is joint work with J. Balakrishnan, N. Dogra, J. Tuitman and J. Vonk and completes the classification of non-CM elliptic curves over the rationals with split Cartan level structure due to Bilu-Parent and Bilu-Parent-Rebolledo.
Thursday, January 31, 2019
16:00-17:00
Utrecht
Complex Systems Seminar
Svetlana Dubinkina (CWI) - Bayesian approach to elliptic inverse problems, HFG 409
Title: Bayesian approach to elliptic inverse problems

Abstract: Predicting the amount of gas or oil extracted from a subsurface
reservoir depends on the soil properties such as porosity and
permeability. These properties, however, are highly uncertain due to the
lack of measurements. Therefore decreasing these uncertainties is of a
great importance.

Mathematically speaking, permeability can be represented by a random
process, which in turn leads to a random partial differential equation.
The solution of such a partial differential equation, for example
pressure, is only partially observed and, moreover, contaminated with
measurement errors. Therefore, instead of a well-posed forward problem
of finding pressure from certain permeability, we are faced with an
ill-posed inverse problem of finding uncertain random process from a few
pressure measurements. We develop a Bayesian method for inverse problems,
that is both general and computationally affordable.
Tuesday, February 5, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Magdalena Kedziorek - t.b.a.
Thursday, February 7, 2019
12:00-13:00
Utrecht
Complex Systems Seminar
Arjan van der Schaft (RUG) - TBA, Min 4.16
15:30-16:30
MIN 2.01
The Mathematical Colloquium
Hector Pasten (PUC Chile) - Bivariate polynomial injections
Abstract:

It is an open problem whether there is a bivariate polynomial f(x,y) with rational coefficients which induces an injective function from the set of pairs of rational numbers into the rational numbers. In the direction of a positive answer, we will prove that there is an affine curve C defined over the rational numbers with a dense set of rational points, and regular polynomial function on CxC which defines an injective function on rational points.
15:30-16:30
MIN 2.01
Staff colloquium
Hector Pasten (PUC, Chile) - t.b.a.
Tuesday, February 12, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Natalia García-Fritz (PUC, Chile) - t.b.a.
Thursday, February 14, 2019
16:00-17:00
Utrecht
Complex Systems Seminar
Felix Beckebanze (UU) - TBA, HFG 611
Tuesday, February 19, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Adrien Sauvaget (Utrecht) - Counting geodesics on flat surfaces
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.
Tuesday, February 26, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Elba García Failde (CEA Saclay) - Simple maps, Hurwitz numbers and topological recursion
In this talk, we call ordinary maps a certain type of graphs embedded on surfaces, in contrast to fully simple maps, which we introduce as maps with non-intersecting disjoint boundaries. It is well-known that the generating series of ordinary maps satisfy a universal recursive procedure, called topological recursion (TR). We propose a combinatorial interpretation of the important and still mysterious symplectic transformation which exchanges $x$ and $y$ in the initial data of the TR (the spectral curve). We give elegant formulas for the disk and cylinder topologies which recover relations already known in the context of free probability. For genus zero we provide an enumerative geometric interpretation of the so-called higher order free cumulants, which suggests the possibility of a general theory of approximate higher order free cumulants taking into account the higher genus amplitudes. We also give a universal relation between fully simple and ordinary maps involving double monotone Hurwitz numbers, which relies on a matrix model interpretation of fully simple maps via the formal hermitian matrix model with external field. In particular, we obtain an ELSV-like formula for double strictly monotone Hurwitz numbers with ramification profile $(2,\ldots,2)$ over $0$ and arbitrary one over $\infty$.
Tuesday, March 5, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Rahul Pandharipande (ETH Zuerich) - Enumerative geometry and the holomorphic anomaly equation
Abstract: I will give a (gentle) introduction to the role of the holomorphic anomaly equation in curve counting problems starting with maps to elliptic curves, proceeding to local toric geometries, and concluding with the famous quintic 3-fold. Though I will discuss joint work with Hyenho Lho, much of what I will say is work of others (Pixton, Oberdieck-Pixton, Chen-Guo-Janda-Ruan, Jun Li and collaborators).
Thursday, March 7, 2019
16:00-17:00
Utrecht
Complex Systems Seminar
Caterina Zeppieri (Universität Münster) - TBA, HFG 611
Tuesday, March 12, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Lóránt Szegedy - t.b.a.
Thursday, March 14, 2019
16:00-17:00
Utrecht
Complex Systems Seminar
Marco Morandotti (TUM) - TBA, HFG 611
Friday, March 15, 2019
09:00-17:00
Mini-Workshop on Symplectic Geometry
MIN 2.02 & KBG Cosmos
09:30-10:30
(a) Alvaro del Pino Gomez - t.b.a.
11:00-12:00
(b) Sonja Hohloch - t.b.a.
13:00-18:00
Min 201
Intercity Number Theory Seminar
13:30-14:30
(c) Tobias Ekholm - t.b.a.
15:00-15:45
t.b.a.
(d) Frances Kirwan - colloquium talk
16:00-16:45
(e) Frances Kirwan - t.b.a.
Tuesday, March 19, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Emily Norton (Universität Bonn) - t.b.a.
Thursday, March 21, 2019
16:00-17:00
Utrecht
Complex Systems Seminar
Matthias Ruf (Universite Libre de Bruxelles) - TBA, HFG 611
Tuesday, March 26, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Christoph Winges (MPIM Bonn) - t.b.a.
Thursday, March 28, 2019
16:00-17:00
Utrecht
Complex Systems Seminar
Cristian Spitoni (UU) - TBA, HFG 611
Tuesday, April 2, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Stefano Marseglia (Universiteit Utrecht) - t.b.a.
Thursday, April 4, 2019
16:00-17:00
Utrecht
Complex Systems Seminar
Michal Branicki (Edinburgh) - TBA, HFG 611
Tuesday, April 9, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Noah Arbesfeld - t.b.a.
Tuesday, April 16, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
David Carchedi (MPIM Bonn) - t.b.a.
Tuesday, April 23, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Manuel Krannich (Cambridge) - t.b.a.
Tuesday, April 30, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
t.b.a. - t.b.a.
Thursday, May 2, 2019
16:00-17:00
Utrecht
Complex Systems Seminar
Patrick Dondl (Universität Freiburg) - TBA, HFG 611
Tuesday, May 7, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Danica Kosanovic (MPIM Bonn) - t.b.a.
Tuesday, May 14, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
t.b.a. - t.b.a.
Tuesday, May 21, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Irakli Patchkoria (Aberdeen) - t.b.a.
Tuesday, May 28, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
t.b.a. - t.b.a.
Tuesday, June 4, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
t.b.a. - t.b.a.
Tuesday, June 11, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
t.b.a. - t.b.a.
Tuesday, June 18, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Juan Cuadra Díaz (Universidad de Almería) - t.b.a.
Tuesday, June 25, 2019
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
t.b.a. - t.b.a.
Tuesday, July 2, 2019
15:30-16:00
HFG Library
Institute Tea
Tuesday, July 9, 2019
15:30-16:00
HFG Library
Institute Tea
Tuesday, July 16, 2019
15:30-16:00
HFG Library
Institute Tea