Mon, 18 Nov 2019

16:00 - 17:00
L4

Minimal surfaces, mean curvature flow and the Gibbons-Hawking ansatz

Jason Lotay
(Oxford)
Abstract

The Gibbons-Hawking ansatz is a powerful method for constructing a large family of hyperkaehler 4-manifolds (which are thus Ricci-flat), which appears in a variety of contexts in mathematics and theoretical physics. I will describe work in progress to understand the theory of minimal surfaces and mean curvature flow in these 4-manifolds. In particular, I will explain a proof of a version of the Thomas-Yau Conjecture in Lagrangian mean curvature flow in this setting. This is joint work with G. Oliveira.

Mon, 11 Nov 2019

16:00 - 17:00
L4

On some computable quasiconvex multiwell functions

Kewei Zhang
(University of Nottingham)
Abstract

The translation method for constructing quasiconvex lower bound of a given function in the calculus of variations and the notion of compensated convex transforms for tightly approximate functions in Euclidean spaces will be briefly reviewed. By applying the upper compensated convex transform to the finite maximum function we will construct computable quasiconvex functions with finitely many point wells contained in a subspace with rank-one matrices. The complexity for evaluating the constructed quasiconvex functions is O(k log k) with k the number of wells involved. If time allows, some new applications of compensated convexity will be briefly discussed.

Mon, 21 Oct 2019

16:00 - 17:00
L4

Quantitative geometric inequalities

Fabio Cavalletti
(SISSA)
Abstract

Localization technique permits to reduce full dimensional problems to possibly easier lower dimensional ones. During the last years a new approach to localization has been obtained using the powerful tools of optimal transport. Following this approach, we obtain quantitative versions of two relevant geometric inequalities  in comparison geometry as Levy-Gromov isoperimetric inequality (joint with F. Maggi and A. Mondino) and the spectral gap inequality (joint with A. Mondino and D. Semola). Both results are also valid in the more general setting of metric measure spaces verifying the so-called curvature dimension condition.

Thu, 17 Oct 2019

16:00 - 17:30
C5

A biased view of two-row Springer theory

Filip Zivanovic
Abstract

Springer theory is an important branch of geometric representation theory. It is a beautiful interplay between combinatorics, geometry and representation theory.
It started with Springer correspondence, which yields geometric construction of irreducible representations of symmetric groups, and Ginzburg's construction of universal enveloping algebra U(sl_n).

Here I will present a view of two-row Springer theory of type A (thus looking at nilpotent elements with two Jordan blocks) from a scope of a symplectic topologist (hence the title), that yields connections between symplectic-topological invariants and link invariants (Floer homology and Khovanov homology) and connections to representation theory (Fukaya category and parabolic category O), thus summarising results by Abouzaid,
Seidel, Smith and Mak on the subject.

Neutrino Astronomy in the IceCube Era
Stanev, T 004 (08 Nov 2017)
Fundamental physics at the intensity frontier. Report of the workshop held December 2011 in Rockville, MD.
Hewett, J Weerts, H Brock, R Butler, J Casey, B Lu, Z Wagner, C Dietrich, M Djurcic, Z Goodman, M Green, J Holt, R Mueller, P Paley, J Reimer, P Singh, J Upadhye, A
Thu, 07 Nov 2019
11:30
C4

Functional Modular Zilber-Pink with Derivatives

Vahagn Aslanyan
(UEA)
Abstract

I will present Pila's Modular Zilber-Pink with Derivatives (MZPD) conjecture, which is a Zilber-Pink type statement for the j-function and its derivatives, and discuss some weak and functional/differential analogues. In particular, I will define special varieties in each setting and explain the relationship between them. I will then show how one can prove the aforementioned weak/functional/differential MZPD statements using the Ax-Schanuel theorem for the j-function and its derivatives and some basic complex analytic geometry. Note that I gave a similar talk in Oxford last year (where I discussed a differential MZPD conjecture and proved it assuming an Existential Closedness conjecture for j), but this talk is going to be significantly different from that one (the approach presented in this talk will be mostly complex analytic rather than differential algebraic, and the results will be unconditional).

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