Mon, 29 Jan 2018

14:15 - 15:15
L5

Compactness results for minimal hypersurfaces with bounded index

Reto Buzano
(Queen Mary University London)
Abstract

First, we will discuss sequences of closed minimal hypersurfaces (in closed Riemannian manifolds of dimension up to 7) that have uniformly bounded index and area. In particular, we explain a bubbling result which yields a bound on the total curvature along the sequence and, as a consequence, topological control in terms of index and area. We then specialise to minimal surfaces in ambient manifolds of dimension 3, where we use the bubbling analysis to obtain smooth multiplicity-one convergence under bounds on the index and genus. This is joint work with Lucas Ambrozio, Alessandro Carlotto, and Ben Sharp

Mon, 22 Jan 2018

14:15 - 15:15
L5

Geometry of subrings

Brent Doran
(Oxford)
Abstract

 The basic algebra-geometry dictionary for finitely generated k-algebras is one of the triumphs of 19th and early 20th century mathematics.  However, classes of related rings, such as their k-subalgebras, lack clean general properties or organizing principles, even when they arise naturally in problems of smooth projective geometry.  “Stabilization” in smooth topology and symplectic geometry, achieved by products with Euclidean space, substantially simplifies many
problems.  We discuss an analog in the more rigid setting of algebraic and arithmetic geometry, which, among other things (e.g., applications to counting rational points), gives some structure to the study of k-subalgebras.  We focus on the case of the moduli space of stable rational n-pointed curves to illustrate.

 

Chemodynamical modelling of the Milky Way
Binney, J Sanders, J Astronomische Nachrichten volume 337 issue 8-9 939-943 (30 Sep 2016)
Self-consistent modelling of our Galaxy with Gaia data
Binney, J Proceedings of the International Astronomical Union volume 12 111-118 (07 Mar 2018)
Wed, 29 Nov 2017
11:00
N3.12

The mystical field with one element

Alex Saad
Abstract

The “field with one element” is an interesting algebraic object that in some sense relates linear algebra with set theory. In a much deeper vein it is also expected to have a role in algebraic geometry that could potentially “lift" Deligne’s proof of the final Weil Conjecture for varieties over finite fields to a proof of the Riemann hypothesis for the Riemann zeta function. The only problem is that it doesn’t exist. In this highly speculative talk I will discuss some of these concepts, and focus mainly on zeta functions of algebraic varieties over finite fields. I will give a (very) brief sketch of how to interpret various zeta functions in a geometric context, and try to explain what goes wrong for the Riemann zeta function that makes this a difficult problem.

Fully Bayesian analysis of conditionally linear Gaussian state space models
Doucet, A Duvaut, P 2013 IEEE International Conference on Acoustics, Speech and Signal Processing volume 5 2948-2951 vol. 5 (01 Jan 1996)
Bayesian estimation of state-space models applied to deconvolution of Bernoulli—Gaussian processes
Doucet, A Duvaut, P Signal Processing volume 57 issue 2 147-161 (Mar 1997)
Marginal MAP estimation using Markov chain Monte Carlo
Robert, C Doucet, A Godsill, S 2013 IEEE International Conference on Acoustics, Speech and Signal Processing volume 3 1753-1756 vol.3 (01 Jan 1999)
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