Eberhard Karls University, Tuebingen

Tue 3 Apr 2018, 3:30pm
Diff. Geom, Math. Phys., PDE Seminar
ESB 2012

TBA

ESB 2012
Tue 3 Apr 2018, 3:30pm4:30pm
Abstract
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University of Washington

Wed 4 Apr 2018, 3:10pm
Probability Seminar
LSK 460

TBA

LSK 460
Wed 4 Apr 2018, 3:10pm4:10pm
Abstract
TBA
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University of British Columbia

Wed 4 Apr 2018, 3:15pm
Topology and related seminars
ESB 4133

TBA

ESB 4133
Wed 4 Apr 2018, 3:15pm4:15pm
Abstract
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Oxford

Thu 5 Apr 2018, 4:00pm
SPECIAL
Algebraic Geometry Seminar

TBA

Thu 5 Apr 2018, 4:00pm5:00pm
Abstract
TBA
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University of Oxford

Fri 6 Apr 2018, 3:00pm
Department Colloquium
ESB 2012

PIMSUBC Distinguished Colloquium: Moduli spaces of unstable curves

ESB 2012
Fri 6 Apr 2018, 3:00pm4:00pm
Abstract
Moduli spaces arise naturally in classification problems in geometry. The study of the moduli spaces of nonsingular complex projective curves (or equivalently of compact Riemann surfaces) goes back to Riemann himself in the nineteenth century. The construction of the moduli spaces of stable curves of fixed genus is one of the classical applications of Mumford's geometric invariant theory (GIT), developed in the 1960s. Here a projective curve is stable if it has only nodes as singularities and its automorphism group is finite. The aim of this talk is to describe these moduli spaces and outline their GIT construction, and then explain how recent methods from nonreductive GIT can help us to classify the singularities of unstable curves in such a way that we can construct moduli spaces of unstable curves (of fixed singularity type).
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Stanford University

Tue 10 Apr 2018, 3:30pm
Diff. Geom, Math. Phys., PDE Seminar
ESB 2012

TBA

ESB 2012
Tue 10 Apr 2018, 3:30pm4:30pm
Abstract
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University of Toronto

Tue 17 Apr 2018, 3:30pm
Diff. Geom, Math. Phys., PDE Seminar
ESB 2012

Geometric Inequalities on Riemannian manifolds

ESB 2012
Tue 17 Apr 2018, 3:30pm4:30pm
Abstract
I will discuss some upper bounds for the length of a shortest periodic geodesic, and the smallest area of a closed minimal surface on closed Riemannian manifolds of dimension 4 with Ricci curvature between 1 and 1. These are the first bounds that use information about the Ricci curvature rather than sectional curvature of the manifold. (Joint with Nan Wu).
I will also give examples of Riemannian metrics on the 3disk demonstrating that the maximal area of 2spheres arising during an ``optimal" homotopy contracting its boundary cannot be majorized in terms of the volume and diameter of the 3disc and the area of its boundary. This contrasts with earlier 2dimensional results of Y. Liokomovich, A. Nabutovsky and R. Rotman and answers a question of P. Papasoglu. On the other hand I will show that such an upper bound exists if, instead of the volume, one is allowed to use the first homological filing function of the 3disc. (Joint with Parker GlynnAdey).
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Note for Attendees
Light refreshments will be served at 2:45pm in ESB 4133, the PIMS Lounge before this colloquium.