Seminars Sorted by Series

Variational Methods in Geometry Seminar

Nov
20
2018

Variational Methods in Geometry Seminar

The min-max width of unit volume three-spheres
Lucas Ambrozio
3:30pm|Simonyi Hall 101

The (Simon-Smith) min-max width of a Riemannian three dimensional sphere is a geometric invariant that measures the tightest way, in terms of area, of sweeping out the three-sphere by two-spheres. In this talk, we will explore the properties of this...

Nov
27
2018

Variational Methods in Geometry Seminar

Homotopical effects of k-dilation
1:00pm|Simonyi Hall 101

Back in the 70s, Gromov started to study the relationship between the Lipschitz constant of a map (also called the dilation) and its topology. The Lipschitz constant describes the local geometric features of the map, and the problem is to understand...

Nov
27
2018

Variational Methods in Geometry Seminar

Bubbling theory for minimal hypersurfaces
Ben Sharp
3:30pm|Simonyi Hall 101

We will discuss the bubbling and neck analysis for degenerating sequences of minimal hypersurfaces which, in particular, lead to qualitative relationships between the variational, topological and geometric properties of these objects. Our aim is to...

Dec
04
2018

Variational Methods in Geometry Seminar

Global results related to scalar curvature and isoperimetry
1:00pm|Simonyi Hall 101

I will first survey some recent progress on global problems related to scalar curvature and area/volume, focusing in particular on scale breaking phenomena in such problems. I will then discuss the role of the Hawking mass in the resolution of this...

Dec
11
2018

Variational Methods in Geometry Seminar

Density and equidistribution of minimal hypersurfaces
1:00pm|Simonyi Hall 101

I will outline the proof of density of minimal hypersurfaces (Irie-Marques-Neves) and equidistribution of minimal hypersurfaces (Marques-Neves-Song).

Dec
11
2018

Variational Methods in Geometry Seminar

Harmonic maps into singular spaces
3:30pm|Simonyi Hall 101

In the 90's, Gromov and Schoen introduced the theory of harmonic maps into singular spaces, in particular Euclidean buildings, in order to understand p-adic superrigidity. The study was quickly generalized in a number of directions by a number of...

Dec
18
2018

Variational Methods in Geometry Seminar

Bounds in Renormalized Volume for Hyperbolic 3-manifolds
Franco Vargas Pallete
1:00pm|Simonyi Hall 101

Renormalized volume (and more generally W-volume) is a geometric quantity found by volume regularization. In this talk I'll describe its properties for hyperbolic 3-manifolds, as well as discuss techniques to prove optimality results.

Jan
15
2019

Variational Methods in Geometry Seminar

Regularity of weakly stable codimension 1 CMC varifolds
1:00pm|Simonyi Hall 101

The lecture will discuss recent joint work with C. Bellettini and O. Chodosh. The work taken together establishes sharp regularity conclusions, compactness and curvature estimates for any family of codimension 1 integral $n$-varifolds satisfying: (i...

Jan
15
2019

Variational Methods in Geometry Seminar

Minimal surfaces with index one in spherical space forms
Celso Viana
3:30pm|Simonyi Hall 101

Minimal surfaces are critical points of the area functional. In this talk I will discuss classification results for minimal surfaces with index one in 3-manifolds with non-negative Ricci curvature and outline the proof that in spherical space forms...

Jan
22
2019

Variational Methods in Geometry Seminar

Symplectic methods for sharp systolic inequalities
Umberto Hryniewicz
1:00pm|Simonyi Hall 101

In this talk I would like to explain how methods from symplectic geometry can be used to obtain sharp systolic inequalities. I will focus on two applications. The first is the proof of a conjecture due to Babenko-Balacheff on the local systolic...

Jan
22
2019

Variational Methods in Geometry Seminar

(Non)uniqueness questions in mean curvature flow
3:30pm|Simonyi Hall 101

Mean curvature flow is the negative gradient flow of the volume functional which decreases the volume of (hyper)surfaces in the steepest way. Starting from any closed surface, the flow exists uniquely for a short period of time, but always develops...

Jan
29
2019

Variational Methods in Geometry Seminar

Minmax minimal surfaces in arbitrary codimension with
Tristan Rivière
1:00pm|Simonyi Hall 101

We shall present a procedure which to any admissible family of immersions of surfaces into an arbitrary closed riemannian manifolds assigns a smooth, possibly branched, minimal surface whose area is equal to the width of the corresponding minmax and...

Jan
29
2019

Variational Methods in Geometry Seminar

The systole of large genus minimal surfaces in positive Ricci curvature
Henrik Matthiesen
3:30pm|Simonyi Hall 101

We prove that the systole (or more generally, any k-th homology systole) of a minimal surface in an ambient three manifold of positive Ricci curvature tends to zero as the genus of the minimal surfaces becomes unbounded. This is joint work with Anna...

Feb
05
2019

Variational Methods in Geometry Seminar

Spacetime positive mass theorem
1:00pm|Simonyi Hall 101

It is fundamental to understand a manifold with positive scalar curvature and its topology. The minimal surface approach pioneered by R. Schoen and S.T. Yau have advanced our understanding of positively curved manifolds. A very important result is...

Feb
05
2019

Variational Methods in Geometry Seminar

On the topology and index of minimal surfaces
3:30pm|Simonyi Hall 101

For an immersed minimal surface in $R^3$, we show that there exists a lower bound on its Morse index that depends on the genus and number of ends, counting multiplicity. This improves, in several ways, an estimate we previously obtained bounding the...

Feb
12
2019

Variational Methods in Geometry Seminar

Min-max solutions of the Ginzburg-Landau equations on closed manifolds
Daniel Stern
1:00pm|Simonyi Hall 101

We will describe recent progress on the existence theory and asymptotic analysis for solutions of the complex Ginzburg-Landau equations on closed manifolds, emphasizing connections to the existence of weak minimal submanifolds of codimension two. On...

Feb
12
2019

Variational Methods in Geometry Seminar

Isoperimetry and boundaries with almost constant mean curvature
3:30pm|Simonyi Hall 101

We review various recent results aimed at understanding bubbling into spheres for boundaries with almost constant mean curvature. These are based on joint works with Giulio Ciraolo (U Palermo), Matias Delgadino (Imperial College London), Brian...

Feb
19
2019

Variational Methods in Geometry Seminar

On minimizers and critical points for anisotropic isoperimetric problems
1:00pm|Simonyi Hall 101

Anisotropic surface energies are a natural generalization of the perimeter functional that arise in models in crystallography and in scaling limits for certain probabilistic models on lattices. This talk focuses on two results concerning...

Feb
19
2019

Variational Methods in Geometry Seminar

Invariant metrics and the Greene-Wu conjectures
3:30pm|Simonyi Hall 101

It has been conjectured that a simply-connected complete Kahler manifold of negatively pinched sectional curvature is biholomorphic to a bounded domain in complex Euclidean space. One evidence is that the manifold is Stein, which is, in particular...

Feb
26
2019

Variational Methods in Geometry Seminar

Geodesic nets: examples and open problems.
1:00pm|Simonyi Hall 101

Geodesic nets on Riemannian manifolds is a natural generalization of geodesics. Yet almost nothing is known about their classification or general properties even when the ambient Riemannian manifold is the Euclidean plane or the round 2-sphere.

In...

Feb
26
2019

Variational Methods in Geometry Seminar

Ancient gradient flows of elliptic functionals
Christos Mantoulidis
3:30pm|Simonyi Hall 101

We study closed ancient solutions to gradient flows of elliptic functionals in Riemannian manifolds, including the mean curvature flow. As an application, we show that an ancient (arbitrarycodimension) mean curvature flow in $S^n$ with low area must...

Mar
12
2019

Variational Methods in Geometry Seminar

Macroscopically minimal hypersurfaces
Hannah Alpert
1:00pm|Simonyi Hall 101

A decades-old application of the second variation formula proves that if the scalar curvature of a closed 3--manifold is bounded below by that of the product of the hyperbolic plane with the line, then every 2--sided stable minimal surface has area...

Mar
19
2019

Variational Methods in Geometry Seminar

Gap and index estimates for Yang-Mills connections in 4-d
1:00pm|Simonyi Hall 101

In this talk I want to discuss two related questions about the variational structure of the Yang-Mills functional in dimension four. The first is the question of 'gap' estimates; i.e., determining an energy threshold below which any solution must be...

Mar
19
2019

Variational Methods in Geometry Seminar

Multiplicity One Conjecture in Min-max theory
3:30pm|Simonyi Hall 101

I will present a proof with some substantial details of the Multiplicity One Conjecture in Min-max theory, raised by Marques and Neves. It says that in a closed manifold of dimension between 3 and 7 with a bumpy metric, the min-max minimal...

Mar
26
2019

Variational Methods in Geometry Seminar

$alpha$-harmonic maps between spheres
Tobias Lamm
1:00pm|Simonyi Hall 101

In a famous paper, Sacks and Uhlenbeck introduced a perturbation of the Dirichlet energy, the so-called $\alpha$-energy $E_\alpha$, $\alpha > 1$, to construct non-trivial harmonic maps of the two-sphere in manifolds with a non-contractible universal...

Mar
26
2019

Variational Methods in Geometry Seminar

A mountain pass theorem for minimal hypersurfaces with fixed boundary
Rafael Montezuma
3:30pm|Simonyi Hall 101

In this talk, we will be concerned with the existence of a third embedded minimal hypersurface spanning a closed submanifold B contained in the boundary of a compact Riemannian manifold with convex boundary, when it is known a priori the existence...

Mar
27
2019

Variational Methods in Geometry Seminar

Multiplicity One Conjecture in Min-max theory (continued)
1:00pm|Simonyi Hall 101

I will present a proof with some substantial details of the Multiplicity One Conjecture in Min-max theory, raised by Marques and Neves. It says that in a closed manifold of dimension between 3 and 7 with a bumpy metric, the min-max minimal...

Apr
02
2019

Variational Methods in Geometry Seminar

Stable hypersurfaces with prescribed mean curvature
1:00pm|Simonyi Hall 101

In recent works with N. Wickramasekera we develop a regularity and compactness theory for stable hypersurfaces (technically, integral varifolds) whose generalized mean curvature is prescribed by a (smooth enough) function on the ambient Riemannian...

Apr
02
2019

Variational Methods in Geometry Seminar

Constrained deformations of positive scalar curvature metrics
3:30pm|Simonyi Hall 101

I will present a series of results concerning the interplay between two different curvature conditions, in the special case when these are given by pointwise inequalities on the scalar curvature of a manifold, and the mean curvature of its boundary...

Apr
09
2019

Variational Methods in Geometry Seminar

The energy functional on Besse manifolds
Marco Radeschi
10:00am|West Building Lecture Hall

A Riemannian manifold is called Besse, if all of its geodesics are periodic. The goal of this talk is to study the energy functional on the free loop space of a Besse manifold. In particular, we show that this is a perfect Morse-Bott function for...

Apr
09
2019

Variational Methods in Geometry Seminar

Bifurcating conformal metrics with constant Q-curvature
Renato Bettiol
3:30pm|Simonyi Hall 101

The problem of finding metrics with constant Q-curvature in a prescribed conformal class is an important fourth-order cousin of the Yamabe problem. In this talk, I will explain how certain variational bifurcation techniques used to prove non...

Apr
25
2019

Variational Methods in Geometry Seminar

Infinite solutions of the singular Yamabe problem in spheres via Teichmüller theory
Paolo Piccione
1:00pm|Simonyi Hall 101

I will discuss a proof of the existence of infinitely many solutions for the singular Yamabe problem in spheres using bifurcation theory and the spectral theory of hyperbolic surfaces.

Apr
30
2019

Variational Methods in Geometry Seminar

The geometry of constant mean curvature surfaces in Euclidean space.
Giuseppe Tinaglia
2:00pm|Simonyi Hall 101

In this talk I will begin by reviewing classical geometric properties of constant mean curvature surfaces, H>0, in R^3. I will then talk about several more recent results for surfaces embedded in R^3 with constant mean curvature, such as curvature...

Venkatesh Working Group