Mathematics Dept.
  Events
University of Bristol
Mon 26 Feb 2018, 3:00pm
Discrete Math Seminar
MATX 1101
Incidences in arbitrary fields
MATX 1101
Mon 26 Feb 2018, 3:00pm-4:00pm

Abstract

The Szemerédi-Trotter theorem gives a sharp upper bound on the maximum number of incidences between any finite sets of points and lines living in the real plane; this has also been extended to the complex plane. We can also ask for such an incidence bound over arbitrary fields. I will talk about two results in this direction in work joint with Frank de Zeeuw. The study of incidence bounds over the reals has found many applications in additive combinatorics; in arbitrary fields this utility remains true, and I shall present some of these applications. 

hide
School of Interactive Computing College of Computing GeorgiaTech
Mon 26 Feb 2018, 3:00pm SPECIAL
Institute of Applied Mathematics
ESB 2012
Optimizing physical contacts for locomotion and manipulation: turning the challenges of contacts into solutions.
ESB 2012
Mon 26 Feb 2018, 3:00pm-4:00pm

Abstract

 

Note for Attendees

Reception before the talk in ESB 4133 (the PIMS lounge). This talk is in the IAM/PIMS distinguished speaker series. 
hide
SFU
Mon 26 Feb 2018, 4:00pm SPECIAL
Algebraic Geometry Seminar
MATX 1118
Fujita's Freeness Conjecture for Complexity-One T-Varieties
MATX 1118
Mon 26 Feb 2018, 4:00pm-5:00pm

Abstract

 Fujita famously conjectured that for a $d$-dimensional smooth
projective variety $X$ with ample divisor $H$, $mH+K_X$ is basepoint
free whenever $m\geq d+1$. I will discuss recent joint work with Klaus
Altmann in which we show this conjecture is true whenever $X$ admits
an effective action by a torus of dimension $d-1$.
hide
University of Toronto
Wed 28 Feb 2018, 3:10pm
Probability Seminar
LSK 460
The global limit of random sorting networks
LSK 460
Wed 28 Feb 2018, 3:10pm-4:10pm

Abstract


A sorting network is a shortest path from the identity to the reverse permutation in the Cayley graph of S_n generated by adjacent transpositions. An n-element uniform random sorting network displays many striking global properties as n approaches infinity. For example, scaled trajectories of the elements 1, 2, ... n converge to sine curves and the 1/2-way permutation matrix measure converges to the projected surface area measure of the 2-sphere.
 
In this talk, I will discuss how the local structure of random sorting networks can be used to find a global limit, proving these statements and more.
hide
ICTS, Bangalore
Wed 28 Feb 2018, 3:15pm
Mathematical Biology Seminar
ESB 4127
Data assimilation and parameter estimation
Shen-Ning Tung
Universitšt Duisburg-Essen
Thu 1 Mar 2018, 3:30pm
Number Theory Seminar
Math 126
On the automorphy of 2-dimensional potentially semistable deformation rings of $\GQp$
Math 126
Thu 1 Mar 2018, 3:30pm-4:30pm

Abstract

Using $p$-adic local Langlands correspondence for $\GL_2(\Qp)$, we prove that the support of patched modules $\Minf(\sigma)[1/p]$ constructed by Caraiani, Emerton, Gee, Geraghty, Paškūnas, and Shin meet every irreducible component of the potentially semistable deformation ring $\Rinf(\sigma)[1/p]$. This gives a new proof of the Breuil-M\'{e}zard conjecture for 2-dimensional representations of the absolute Galois group of $\Qp$ when $p \geq 3$, which is new in the case $p=3$ and $\rbar$ a twist of the trivial character by the mod $p$ cyclotomic character. As a consequence, the local restriction in the proof of Fontaine-Mazur conjecture by Kisin is removed.
hide