Spectral geometry in the clouds
Intergalactic seminar on spectral theory and geometric analysis


Fall 2023
September
September 11

Cyril Letrouit
Maximal multiplicity of Laplacian eigenvalues in negatively curved surfaces
Video

September 18

Michela Egidi
Complex analysis, thick sets, and spectral inequalities
Video

September 25

Yves Colin de Verdière
On the spectrum of the Poincaré operator in ellipsoids
Video

October
October 2

Sam Farrington
On the geometric stability of Weyl's law and some applications to asymptotic spectral shape optimisation
Video

October 9

Jonathan Rohleder
Inequalities between Neumann and Dirichlet Laplacian eigenvalues on planar domains
Video

October 16

Antoine Métras
Dirac eigenvalue optimization
Video

October 23

Wadim Gerner
Optimal Metrics and Domains for the first Curl eigenvalue

October 30

Ana Menezes
Eigenvalue problems and free boundary minimal surfaces in spherical caps

November
November 6, 8, 10

GEMSTONE mini-course
Dorin Bucur

Shape optimization of spectral functionals

November 13

Sara Farinelli
Peijel's nodal domain theorem in spaces with synthetic Ricci curvature lower bounds
Video

November 20

Samuel Lin
Spectral Multiplicity and Nodal Domains of Torus-invariant Metrics
Video

November 27

Dan Mangoubi
On the inner radius of nodal domains

December
December 4

Matthew Kwan
Exponentially many graphs are determined by their spectrum
Video

December 11

Denis Grebenkov
Probabilistic and numerical insights onto the spectral properties of the Dirichlet-to-Neumann operator




Winter 2023
January
January 16

Nikolay Filonov
Polya's conjecture for Euclidean balls
Video

January 23

Badreddine Benhellal
Curvature contribution to the essential spectrum of Dirac operators with critical shell interactions
Video

January 30

Break

February
February 6

Romain Petrides
A variational method for functionals depending on eigenvalues
Video

February 13

Peter McGrath
Free Boundary Minimal Annuli Immersed in the 3-Ball
Video

February 20

Maxime Fortier Bourque
Linear programming bounds for hyperbolic surfaces
Video

February 27

Laura Monk
Towards an optimal spectral gap result for random compact hyperbolic surfaces
Video

March
March 6

Yaiza Canzani
Counting closed geodesics and improving Weyl’s law for predominant sets of metrics
Video

March 13

Francesca Bianchi
The first eigenvalue of fractional Dirichlet-Laplacian for planar sets with topological constraints
Video

March 20

Blake Keeler
Off-diagonal spectral cluster asymptotics On Zoll manifolds
Video

March 27, 29, 31

GEMSTONE mini-course 3
Geometry and spectrum of random hyperbolic surfaces

April
April 3

Ilaria Fragalà
Riesz inequality for polygons: symmetry and symmetry breaking
Video

April 10

Luc Hillairet
Spectral tools for geometric degeneration
Video

April 17

Jake Fillman
Spectral properties of operators on aperiodic graphs

April 24

Michela Egidi
Complex analysis, thick sets, and spectral inequalities




Fall 2022
December
December 12

Mikhail Dubashinskiy
Growth and divisor of complexified horocycle eigenfunctions
Slides

December 5

Mickael Nahon
Sharp stability of higher order Dirichlet eigenvalues
Video

November
November 28

María del Mar González Nogueras
Third order boundary eigenvalue problems
Video

November 21

Frédéric Naud
Spectrum of random covers of hyperbolic surfaces and GOE/GUE statistics
Video

November 14

Marco Michetti
Maximization of Neumann eigenvalues under diameter constraint
Video

November 7

Clara Lucia Aldana Dominguez
On Quasi-isospectral potentials
Video

October
October 31

Anke Pohl
Fractal Weyl bounds
Video

October 24

Polyxeni Spilioti
Twisted Ruelle zeta function on locally symmetric spaces, the Fried’s conjecture and further applications
Video

October 17

Alexei Stepanenko
Computing eigenvalues of the Laplacian on rough domains
Video

October 10

Mostafa Sabri
Quantum ergodicity for periodic graphs
Video

October 3

Bram Petri
How do you efficiently chop a hyperbolic surface in two?
Video

September
September 26

Semyon Dyatlov
Ruelle zeta at zero for nearly hyperbolic 3-manifolds
Video

September 19

Break

September 12

Maxime Ingremeau
How Lagrangian states evolve into random waves
Video

September 5

Egor Shelukhin
Coarse nodal count and topological persistence




Spring and summer 2022
July
July 11

Melanie Rupflin
Almost harmonic maps from higher genus surfaces
Video

July 4

Nadine Große
Boundary value problems on domain with cusps
Video

June
June 27

Nunzia Gavitone
An eigenvalue problem for the Laplace operator in doubly connected domains
Video

June 20

Andrea Mondino
Optimal transport and quantitative geometric inequalities
Video

June 13

Dennis Kriventsov
Stability for Faber-Krahn inequalities and the ACF formula
Video

June 6

Jiaoyang Huang
Extreme eigenvalues of random \(d\)-regular graphs
Video

May
May 30

Romain Petrides
Minimizing combinations of Laplace eigenvalues and applications
Video

May 23

Dorin Bucur
Maximization of Neumann eigenvalues
Video

May 16

Yves Colin de Verdière
Attractors for internal or inertial waves
Video

May 9

Beniamin Bogosel
On the polygonal Faber-Krahn inequality
Video

May 2

Pedro Freitas
Pólya-type inequalities on spheres and hemispheres
Video




Winter 2022
April
April 25

GEMSTONE mini-course
Mikhail Karpukhin and Daniel Stern
Harmonic maps, minimal surfaces, and shape optimization in spectral geometry

April 18

Break

April 11

Jean Lagacé
Variations on the Weyl law for the Steklov problem on surfaces
Video

April 4

Bruno Colbois
Upper bounds for Steklov eigenvalues
Video

March
March 28

Mikhail Cherdantsev
Stochastic homogenisation of high-contrast media
Video

March 21

Young researchers in spectral geometry IV

March 14

James Bonifacio
Bootstrap bounds on closed hyperbolic surfaces
Video

March 7

Nelia Charalambous
The form spectrum of open manifolds
Video

February
February 28

Ilaria Lucardesi
On the maximization of the first (non trivial) Neumann eigenvalue of the Laplacian under perimeter constraint

February 21

Malo Jézéquel
Semiclassical measures for higher dimensional quantum cat maps
Video

February 14

Maxime Fortier Bourque
The multiplicity of \(\lambda_1\) in genus 3
Video

February 7

Francesco Ferraresso
Neumann and intermediate biharmonic eigenvalue problems on sigularly perturbed domains
Video

January
January 31

Alessandro Savo
Isoperimetric inequalities for the lowest Aharonov-Bohm eigenvalue of the Neumann and Steklov problems
Video

January 24

Gregory Berkolaiko
Towards Morse theory of dispersion relations
Video

January 17

Oleksiy Klurman
Boundary-adapted arithmetic random waves and spectral semi-correlations
Video




Fall 2021
December
December 13

Yann Chaubet
Closed geodesics with prescribed intersection numbers
Video

December 6

Jean-Claude Cuenin
Schrödinger operators with complex potentials: Beyond the Laptev-Safronov conjecture
Video

November
November 29

David Sher
Nodal counts for the Dirichlet-to-Neumann operator
Video

November 22

Michael Magee
The maximal spectral gap of a hyperbolic surface

November 15

Ben Sharp
Łojasiewicz-type inequalities for the H-functional near simple bubble trees
Video

November 8

Sabine Boegli
On the discrete eigenvalues of Schrödinger operators with complex potentials
Video

November 1

Jonathan Rohleder
Note the change of time this week: 9h PST -- 12h EST -- 16h GMT -- 17h CET
A new approach to the hot spots conjecture
Video

October
October 25

Valentin Blomer
Eigenvalue statistics of flat tori
Video

October 18

Daniel Stern
Note the change of time this week: 8h PST -- 11h EST -- 16h BST -- 17h CEST
Steklov-maximizing metrics on surfaces with many boundary components
Video

October 11

Break

October 4

Philippe Charron
Pleijel's theorem for Schrödinger operators
Video

September
September 27

Gabriel Rivière
Poincaré series and linking of Legendrian knots
Video

September 20

Martin Vogel
Spectral asymptotics of noisy non-selfadjoint operators
Video

September 13

Young researchers in spectral geometry III
3 short talks

September 6

Nalini Anantharaman
Quantum ergodicity for expanding quantum graphs in the regime of spectral delocalization
Video

August
August 30

Jürgen Jost
Spectra of graphs and hypergraphs
Video

August 23

Wencai Liu
Small denominators and large numerators of quasiperiodic Schroedinger operators
Video




Spring and summer 2021
August
August 2, 9 and 16: break
July
July 26

Victor Ivrii
Pointwise Spectral Asymptotics out of the Diagonal
Video

July 19

Yannick Sire
Eigenfunction and cluster estimates for Schrodinger operators on manifolds
Video

July 12

Derek Kielty
Degeneration of the spectral gap with negative Robin parameter
Video

July 5

Steve Zelditch
Eigenfunction restriction problems
Video

June
June 28

Ari Laptev
Spectral inequalities for Jacobi matrices following Hundertmark and Simon
Video

June 21

Paolo Luzzini
On the spectral asymptotics for the buckling problem
Video

June 14

Javier Gómez-Serrano
Computer-assisted proofs and counterexamples in spectral geometry
Video

June 7

Mikhail Karpukhin
Stability of isoperimetric eigenvalue inequalities
Video

May
May 31

Maciej Zworski
Spectral theory of internal waves in fluids
Video

May 24

Genqian Liu
Geometric invariants of spectrum of the Navier-Lame operator
Video

May 17

Alexandre Girouard
Free boundary minimal surfaces and large Steklov eigenvalues
Video

May 10

Ram Band
Neumann domains on manifolds and graphs
Video

May 3

Jared Wunsch
Semiclassical analysis and the convergence of the finite element method
Video




Winter 2021
April
April 26

Karl-Mikael Perfekt
Infinitely many embedded eigenvalues for the Neumann-Poincaré operator in 3D
Video

April 19

Bernard Helffer
Semi-classical edge states for the Robin Laplacian (after Helffer-Kachmar)
Video

April 12

Svitlana Mayboroda
The landscape law for the integrated density of states
Video

April 5

Break

March
March 29

Mariel Saez
Eigenvalue bounds for the Paneitz operator and its associated boundary operator
Video

March 21 and 22

Mini Conference
Young researchers in spectral geometry II

March 15

Nilima Nigam
The approximation of Laplace Steklov eigenvalues
Video

March 8

Graham Cox
Nodal deficiency via equipartitions and Dirichlet-to-Neumann maps
Video

March 1

Grigori Rozenblum
Eigenvalue estimates and asymptotics for weighted pseudodifferential operators with singular measures in the critical case
Video

February
February 22

Peter Kuchment
Spectral shift via lateral variation
Video

February 15

Uzy Smilansky
Can one hear a matrix?
The determination of a real symmetric matrix from spectral information

February 8

Alessandro Carlotto
Free boundary minimal surfaces with connected boundary and arbitrary genus

February 1

Luigi Provenzano
Spectral representation of the trace spaces of H² and biharmonic Dirichlet problems for multi-parameter Steklov problems
Video

January
January 25

Zeev Rudnick
Robin vs Neumann spectra for planar domains

January 18

Pavel Exner
Discrete spectrum of Dirichlet Laplacian in spiral-shaped regions
Video

January 11

Olaf Post
Operator estimates for wildly perturbed manifolds
Video




Fall 2020
December
December 14

Marco Marletta
A Laplace operator with boundary conditions singular at one point
Video

December 7

Simon Larson
Two-term spectral asymptotics for the Dirichlet Laplacian in a Lipschitz domain
Video

November
November 30

Édouard Oudet
Metric Optimization in Spectral geometry
Video

November 23

Peter Sarnak
Gap Sets for the Spectra of Cubic Graphs
Video

November 16

Katie Gittins
Upper bounds for Steklov eigenvalues
Video

November 9

Jeffrey Galkowski
The interior behavior of Steklov eigenfunctions
Video

November 2

Stefano Decio
Nodal sets of Steklov eigenfunctions near the boundary
Video

October
October 26

Christiane Tretter   
Spectral problems on star graphs
Video

October 19

Antoine Henrot
Isodiametric inequalities for eigenvalues
Video

October 12

Sugata Mondal   
Hot spots conjecture for polygonal domains
Video

October 5

Richard Laugesen
Two balls maximize the third Neumann eigenvalue in hyperbolic space
Video Slides

September
September 28

Jeremy Marzuola
A local test for global extrema in the dispersion relation for periodic graphs
Video

September 21

Davide Buoso
The Bilaplacian with Robin boundary conditions
Video

September 14

Alix Deleporte
Semiclassical analysis of a problem with a circular well
Video

September 7

Jean Lagacé
Measure theoretic methods in spectral shape optimisation
Video

August
August 31

Gerasim Kokarev
Comparison principles, minimal surfaces, and eigenvalue inequalities




Spring and summer 2020

August 24

Special seminar on the occasion of Dima Jakobson's 50th birthday

August 3 and 4

Mini Conference: Young researchers in spectral geometry

July
July 27

Julie Rowlett
Same-same but different: Polyakov formulas via microlocal analysis and mathematical physics
Video

July 20

Asma Hassannezhad
Eigenvalue bounds for the mixed Steklov problem
Video

July 13

Panagiotis Polymerakis
Bottom of spectra and coverings

July 6

Rupert Frank
Sharp Weyl Laws in 3d with rough potentials
Slides Video

June
June 29

Daniel Stern
Min-max harmonic maps and extremal metrics for Laplacian eigenvalues
Slides Video

June 22

Stefan Steinerberger
Nodal Sets of Eigenfunctions: Progress via Optimal Transport
Slides Video

June 15

Cristina Trombetti
Sharp Estimates for solutions to Elliptic Equations with Robin boundary conditions
Video

June 8

Peter Humphries
The random wave conjecture and arithmetic quantum chaos
Slides Video

June 1

Xuwen Zhu
Spectral properties of reducible spherical conical metrics
Video

May
May 25

Iosif Polterovich
Lambdas, bubbles, and spheres
Slides Video

May 18

Yaiza Canzani
\(L^p\)-norms via geodesic beams.
Video

May 11

Henrik Matthiesen
Asymptotic behaviour of eigenvalues in glueing constructions and new minimal surfaces via shape optimization
Notes Video

May 4

Dorin Bucur
Stable and unstable spectral inequalities
Video

April
April 27

Emilio Lauret
On the first Laplace eigenvalue of a homogeneous sphere
Slides

April 20

Michael Levitin
Inverse Steklov spectral problem for curvilinear polygons
Slides