Math Calendar

Friday, April 20, 2018
11:00-13:00
HFG 610
Friday Fish
Francesco Cattafi - EDSs and PDEs
In this talk we will explore three important classes of EDSs: the aim is on one side to highlight their connections with PDEs and on the other to lay the groundwork for the study of prolongations.
An independence conditions for an EDS consists of a class of differential forms not belonging to the ideal; every PDE can be written as an EDS with a natural independence condition, corresponding to the choice of the independent variables.
Involutivity is the existence of an ordinary integral element at any point: for real-analytic EDSs, this is precisely the hypothesis to apply Cartan-Kähler and get integral manifolds through every point. We will give the examples of an involutive EDS (the one given by an involutive distribution) and a non-involutive one (having an extra "hidden" integrability condition).
Last, all EDSs induced by PDEs turn out to be examples of Pfaffian systems with a certain "linearity" property (with an unfortunate choice of name); indeed, we conclude reviewing the definition of Pfaffian bundle (the "geometric structure" encoding a PDE on a jet bundle) and showing that it also induces a linear Pfaffian system with an independence condition.
14:00-16:00
HFG 610
Friday Fish
Joost Nuiten - Derived stacks
Last week we saw how singular intersections can locally be described by affine derived schemes. After a brief recollection, I will discuss how singular quotients can be described by derived stacks. In the first half of the talk, I will describe stacks in the smooth setting, in terms of Lie groupoids. In the second half, I will give an analogous description of derived stacks and discuss the cotangent bundle of a derived stack.
Monday, April 23, 2018
15:00-17:00
HFG 610
Master Seminar on Quadratic Forms
Berend Ringeling - The Brauer Wall group
Tuesday, April 24, 2018
13:15-15:00
HFG 610
Master Seminar on topological K-theory
Matthijs Lip - Construction of characteristic classes
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Jaclyn Lang (MPIM Bonn) - Images of domain-valued GL2-type Galois representations
Abstract: There is a general philosophy that the image of a Galois representation should be as large as possible, subject to the symmetries of the geometric object from which it arose.  This can be seen in Serre's open image theorem for non-CM elliptic curves, Ribet and Momose's work on Galois representations attached to modular forms, and recent work of the speaker and Conti, Iovita, Tilouine on Galois representations attached to Hida and Coleman families of modular forms.  Recently, Bellaiche developed a way to measure the image of an arbitrary Galois representation taking values in GL2 of a local ring A.  Under the assumptions that A is a domain and the residual representation is not too degenerate, we explain how the symmetries of such a representation are reflected in its image.  This is joint work with Andrea Conti and Anna Medvedovsky.
Monday, April 30, 2018
15:00-17:00
HFG 610
Master Seminar on Quadratic Forms
Jeroen Huijben - Clifford algebras
Tuesday, May 1, 2018
13:15-15:00
HFG 610
Master Seminar on topological K-theory
Bjarne Kosmeijer - Thom isomorphism in K-theory and cohomology
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Yaël Fregiér (Lens) - t.b.a.
Monday, May 7, 2018
15:00-17:00
HFG 610
Master Seminar on Quadratic Forms
Marc Houben - Structure of Clifford algebras
Tuesday, May 8, 2018
13:15-15:00
HFG 610
Master Seminar on topological K-theory
t.b.a. - t.b.a.
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
t.b.a. () - t.b.a.
Monday, May 14, 2018
15:00-17:00
HFG 610
Master Seminar on Quadratic Forms
t.b.a. - Invariants of Clifford algebras
Tuesday, May 15, 2018
13:15-15:00
HFG 610
Master Seminar on topological K-theory
Luka Zwaan - Euler classes and Pontryagin classes
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Irakli Patchkoria (Bonn) - t.b.a.
Thursday, May 17, 2018
16:00-17:00
HFG 611
Complex Systems Seminar
Bezoeker Kreisbeck (UU) - TBA
Title:
Abstract:
Tuesday, May 22, 2018
13:15-15:00
HFG 610
Master Seminar on topological K-theory
t.b.a. - t.b.a.
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Rachel Newton (University of Reading) - t.b.a.
Monday, May 28, 2018
15:00-17:00
HFG 610
Master Seminar on Quadratic Forms
t.b.a. - t.b.a.
Tuesday, May 29, 2018
12:00-13:00
HFG Library
Bring Your Own Lunch (BYOL)
13:15-15:00
HFG 610
Master Seminar on topological K-theory
t.b.a. - t.b.a.
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Milan Lopuhaä-Zwakenberg (Nijmegen) - t.b.a.
Monday, June 4, 2018
15:00-17:00
HFG 610
Master Seminar on Quadratic Forms
t.b.a. - t.b.a.
Tuesday, June 5, 2018
13:15-15:00
HFG 610
Master Seminar on topological K-theory
t.b.a. - t.b.a.
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Clément Dupont (Université de Montpellier) - t.b.a.
Monday, June 11, 2018
15:00-17:00
HFG 610
Master Seminar on Quadratic Forms
t.b.a. - t.b.a.
Tuesday, June 12, 2018
13:15-15:00
HFG 610
Master Seminar on topological K-theory
t.b.a. - t.b.a.
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, June 14, 2018
15:30-16:30
Ruppert ROOD
Kan Lecture / Mathematical Colloquium
Eric Friedlander (USC) - TBA
Monday, June 18, 2018
15:00-17:00
HFG 610
Master Seminar on Quadratic Forms
t.b.a. - t.b.a.
Tuesday, June 19, 2018
12:00-13:00
HFG Library
Bring Your Own Lunch (BYOL)
13:15-15:00
HFG 610
Master Seminar on topological K-theory
t.b.a. - t.b.a.
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, June 21, 2018
16:00-17:00
Extra Number Theory Talk
Mikhail Borovoi (Tel Aviv University) - Cayley groups, MIN 2.06
Abstract
 I will start the talk from the classical "Cayley transform" for the special orthogonal group SO(n) defined by Arthur Cayley in 1846. A connected linear algebraic group G over C is called a *Cayley group* if it admits a *Cayley map*, that is, a G-equivariant birational isomorphism between the group variety G and its Lie algebra Lie(G). For example, SO(n) is a Cayley group.  A linear algebraic group G is called *stably Cayley* if G x S is Cayley for some torus S. I will consider semisimple algebraic groups, in particular, simple algebraic groups. I will describe classification of Cayley simple groups and of stably Cayley semisimple groups. (Based on joint works with Boris Kunyavskii and others.)
Monday, June 25, 2018
15:00-17:00
HFG 610
Master Seminar on Quadratic Forms
t.b.a. - t.b.a.
Tuesday, June 26, 2018
13:15-15:00
HFG 610
Master Seminar on topological K-theory
t.b.a. - t.b.a.
15:30-16:00
HFG Library
Institute Tea
16:00-17:00
HFG 611
Utrecht Geometry Center Seminar
Diogo Oliveira e Silva (University of Birmingham, UK) - t.b.a.
Tuesday, July 3, 2018
13:15-15:00
HFG 610
Master Seminar on topological K-theory
t.b.a. - t.b.a.
15:30-16:00
HFG Library
Institute Tea
Tuesday, July 10, 2018
13:15-15:00
HFG 610
Master Seminar on topological K-theory
t.b.a. - t.b.a.
15:30-16:00
HFG Library
Institute Tea
Tuesday, July 17, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, July 24, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, July 31, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, August 7, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, August 14, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, August 21, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, August 28, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, September 4, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, September 11, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, September 18, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, September 25, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, October 2, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, October 9, 2018
15:30-16:00
HFG Library
Institute Tea
Tuesday, October 16, 2018
15:30-16:00
HFG Library
Institute Tea