Mathematical Sciences Research Institute

Home > Scientific > Colloquia & Seminars > All Colloquia & Seminars

Current Seminars

No current seminar

1. HDMP - Special Seminar (part 1) - Smooth compactifications of strata of differentials, with examples

Location: MSRI: Simons Auditorium
Speakers: Samuel Grushevsky (State University of New York, Stony Brook), Martin Moeller (Johann Wolfgang Goethe-Universität Frankfurt)

We will describe the geometry of a smooth functorial compactification of the strata. That is, we will describe a compact algebraic variety that parameterizes the data of certain geometric multi-scale differentials, which compactifies the locus of smooth Riemann surfaces together with a differential with prescribed zeroes and poles. The multi-scale differentials are certain collections of meromorphic differentials on the components of nodal Riemann surfaces, together with some extra data. We will describe the general construction and define the objects, and then discuss a few low-dimensional cases in full detail.

Updated on Aug 22, 2019 01:38 PM PDT
2. HDMP - Special Seminar (part 2) - Smooth compactifications of strata of differentials, with examples

Location: MSRI: Simons Auditorium
Speakers: Samuel Grushevsky (State University of New York, Stony Brook), Martin Moeller (Johann Wolfgang Goethe-Universität Frankfurt)

We will describe the geometry of a smooth functorial compactification of the strata. That is, we will describe a compact algebraic variety that parameterizes the data of certain geometric multi-scale differentials, which compactifies the locus of smooth Riemann surfaces together with a differential with prescribed zeroes and poles. The multi-scale differentials are certain collections of meromorphic differentials on the components of nodal Riemann surfaces, together with some extra data. We will describe the general construction and define the objects, and then discuss a few low-dimensional cases in full detail.

Updated on Aug 22, 2019 01:50 PM PDT
3. MLA - Interactions of Semilinear Conormal Singularities

Location: MSRI: Simons Auditorium
Speakers: Antônio Sá Barreto (Purdue University)

We discuss the propagation of conormal singularities of solutions of  $P(y,D) u= f(y,u),$  $y \in \mathbb{R}^n,$ $n\geq 3,$ where $P(y,D)$ is a second order strictly hyperbolic operator and $f\in C^\infty.$

Updated on Aug 22, 2019 09:33 AM PDT
4. HDMP - Weekly Seminar (part 1) - On triply periodic polyhedral surfaces

Location: MSRI: Simons Auditorium
Speakers: Dami Lee (University of Washington)

A classical question in geometry is whether surfaces with given geometric features can be realized as surfaces in Euclidean space. We will investigate surfaces with cone metrics and find concrete examples of triply periodic polyhedra that have identifiable conformal structures.

Related questions are

1. How do we come up with examples?

2. Are there (if so, how many) saddle connections on infinite polyhedra with their natural polyhedral metric? What are their Veech groups?

3. Furthermore, these examples connect to Novikov’s problem on hyperplane sections. The intersection of a triply periodic polyhedral surface $P$ and a hyperplane $H$ yields one-dimensional curves which are level sets of a 1-form on the surface. Then what can we say about the set $\{\omega H\}$ as we vary $H,$ thinking of it as a subset of the vector space of holomorphic 1-forms on the intersection. In other words, what does the family of translation surfaces look like?

These questions lie in the intersection of flat geometry and dynamics. It is also known that the motivation for Novikov’s problem comes from physics where periodic surfaces in $\mathbb{R}^3$ are understood as a Fermi surface of some metal, and the plane sections can be explained as a hyperplane orthogonal to the magnetic field.

In this talk, instead of answering these questions, we will discuss very specific examples of polyhedral surfaces and describe the questions that are asked above.

Updated on Aug 23, 2019 11:18 AM PDT
5. HDMP-Weekly Seminar (part 2) - Bridgeland stability and quadratic differentials

Location: MSRI: Simons Auditorium
Speakers: Alex Takeda (University of California, Berkeley)

This talk will be an introduction to Bridgeland stability conditions on triangulated categories, oriented towards researchers in the field of quadratic differentials. After introducing the definitions and working out some explicit examples of spaces of stability conditions, I will summarize the results of Bridgeland-Smith and Haiden-Katzarkov-Kontsevich, which are two different, but related, appearances of quadratic differentials in the study of stability conditions. Time allowing I will discuss some of my results on the subject.

Updated on Aug 23, 2019 11:19 AM PDT
6. MLA - Weekly Seminar (part 1) - Eigenmodes of the Laplacian on Surfaces of Negative Curvature

Location: MSRI: Simons Auditorium
Speakers: Stephane Nonnenmacher (Université de Paris XI)

(joint work with Semyon Dyatlov and Long Jin)

The eigenmodes of the Laplacian on a smooth compact Riemannian manifold $(M,g)$ can exhibit various localization properties in the high frequency limit, which depend on the properties of the geodesic flow on $(M,g)$.

I will focus on a "quantum chaotic" situation, namely assume that the geodesic flow is strongly chaotic (Anosov); this is the case if the sectional curvature of $(M,g)$ is strictly negative. The Quantum Ergodicity theorem then states that almost all eigenmodes become equidistributed on $M$ in the the high-frequency limit. The Quantum Unique Ergodicity conjecture states that this behaviour suffers no exception, namely all eigenstates equidistribute in this limit.

This conjecture remaining open, a less ambitious goal is to constrain the possible localization behaviours of the eigenmodes. I will report on recent progress in the case of negative curvature surfaces. Generalizing a previous work by Dyatlov-Jin in the constant curvature case, we show that the eigenmodes cannot concentrate on a proper subset of $M$, in the high frequency limit.

More precisely, any semiclassical measure associated with the sequence of eigenmodes must have full support on $S^*M$. The proof uses the foliation of the phase space into stable and unstable manifolds, methods from semiclassical analysis, and a new Fractal Uncertainty Principle due to Bourgain-Dyatlov, which I will use as a "black box". I plan to describe the strategy of proof in the constant curvature case, and indicate the necessary modifications in the variable curvature setting.

Updated on Aug 23, 2019 11:09 AM PDT
7. MLA - Weekly Seminar (part 2) - Eigenmodes of the Laplacian on Surfaces of Negative Curvature

Location: MSRI: Simons Auditorium
Speakers: Stephane Nonnenmacher (Université de Paris XI)

(joint work with Semyon Dyatlov and Long Jin)

The eigenmodes of the Laplacian on a smooth compact Riemannian manifold $(M,g)$ can exhibit various localization properties in the high frequency limit, which depend on the properties of the geodesic flow on $(M,g)$.

I will focus on a "quantum chaotic" situation, namely assume that the geodesic flow is strongly chaotic (Anosov); this is the case if the sectional curvature of $(M,g)$ is strictly negative. The Quantum Ergodicity theorem then states that almost all eigenmodes become equidistributed on $M$ in the the high-frequency limit. The Quantum Unique Ergodicity conjecture states that this behaviour suffers no exception, namely all eigenstates equidistribute in this limit.

This conjecture remaining open, a less ambitious goal is to constrain the possible localization behaviours of the eigenmodes. I will report on recent progress in the case of negative curvature surfaces. Generalizing a previous work by Dyatlov-Jin in the constant curvature case, we show that the eigenmodes cannot concentrate on a proper subset of $M$, in the high frequency limit.

More precisely, any semiclassical measure associated with the sequence of eigenmodes must have full support on $S^*M$. The proof uses the foliation of the phase space into stable and unstable manifolds, methods from semiclassical analysis, and a new Fractal Uncertainty Principle due to Bourgain-Dyatlov, which I will use as a "black box". I plan to describe the strategy of proof in the constant curvature case, and indicate the necessary modifications in the variable curvature setting.

Updated on Aug 23, 2019 11:11 AM PDT
8. Topics in Differential Geometry (Chancellor Course)

Location: Evans Hall 891
Speakers: François Labourie (Université Côte d'Azur)
Updated on Aug 20, 2019 08:58 AM PDT
9. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
10. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
11. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
12. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
13. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
14. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
15. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
16. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
17. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
18. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
19. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
20. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
21. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
22. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
23. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
24. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
25. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
26. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
27. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
28. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
29. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
30. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
31. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
32. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
33. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
34. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
35. Microlocal Analysis and Spectral Theory: A Conference in Honor of Richard Melrose

Location: UC Berkeley Math
Speakers: Nalini Anantharaman (Université de Strasbourg), Yaiza Canzani (Harvard University), Semyon Dyatlov (University of California, Berkeley), Colin Guillarmou (Université de Paris XI (Paris-Sud)), Victor Guillemin (Massachusetts Institute of Technology), Peter Hintz (Massachusetts Institute of Technology), Gilles Lebeau (Université Nice Sophia-Antipolis), Laure Saint-Raymond, Peter Sarnak (Princeton University), Terence Tao (University of California, Los Angeles), Akshay Venkatesh (Institute for Advanced Study)

This will be a conference on the wide range of topics aimed to inspire future directions and new applications of microlocal methods.

Updated on Jun 18, 2019 01:45 PM PDT
36. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
37. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
38. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
39. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
40. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
41. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
42. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
43. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
44. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
45. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
46. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
47. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
48. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
49. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
50. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
51. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
52. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
53. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
54. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
55. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
56. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
57. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
58. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
59. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
60. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
61. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT
62. Topics in Differential Geometry (Chancellor Course)

Location: Evans 891
Speakers: François Labourie (Université Côte d'Azur)
Created on Aug 19, 2019 03:58 PM PDT
63. HDMP - Weekly Seminar (Part 1)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:35 PM PDT
64. HDMP-Weekly Seminar (Part 2)

Location: MSRI: Simons Auditorium
Created on Aug 21, 2019 04:38 PM PDT

1. SeminarThe Feynman propagator on a curved spacetime

Updated on Aug 12, 2019 03:43 PM PDT
2. SeminarElliptic Cohomology Learning Group: Tempered cohomology

Updated on May 15, 2019 09:21 AM PDT
3. SeminarDAG Learning Seminar: Derived Satake

Updated on May 06, 2019 04:35 PM PDT
4. SeminarWomen at MSRI lunch

Created on Feb 13, 2019 03:50 PM PST
5. SeminarAlgebraic Geometry colloquium: Local, Global and Local to Global properties and singularities in (birational) algebraic geometry, topology, strings (and moduli of Calabi-Yau)

Updated on May 15, 2019 09:24 AM PDT
6. SeminarWhat in the world are spectra? Spectra, excisive functors, and stable infinity-categories

Updated on May 08, 2019 04:51 PM PDT
7. SeminarBGMS Seminar: From Brill-Noether loci in K3 categories to surfaces on cubic fourfolds

Updated on May 16, 2019 11:23 AM PDT
8. SeminarMeasures on spheres using Langlands, after Drinfeld

Created on May 10, 2019 04:03 PM PDT
9. SeminarDAG Seminar: A new approach to Goerss-Hopkins obstruction theory

Updated on May 15, 2019 09:30 AM PDT
10. SeminarGraduate Student Seminar: Relative log canonical models for elliptic fibrations

Updated on May 07, 2019 04:49 PM PDT
11. SeminarIrregular local systems working group: Irregular Riemann-Hilbert

Created on May 10, 2019 04:04 PM PDT
12. SeminarIrregular local systems working group: Good lattices of algebraic connections

Updated on May 09, 2019 03:01 PM PDT
13. SeminarBGMS Seminar: Compactifying moduli of complex curves with a differential

Updated on May 09, 2019 01:10 PM PDT
14. SeminarFuture directions lectures: Rationality of hypersurfaces

Updated on May 10, 2019 09:12 AM PDT
15. SeminarAlgebraic Geometry colloquium: Purity in bad characteristics

Updated on May 07, 2019 03:09 PM PDT
16. SeminarDAG Learning Seminar: Ordinary Satake

Updated on May 06, 2019 04:27 PM PDT
17. SeminarFuture directions lectures: Valuation, finite generation, and K-stability

Updated on May 10, 2019 09:11 AM PDT
18. SeminarDAG Seminar: Frobenius structures on arithmetic connections

Updated on May 06, 2019 12:19 PM PDT
19. SeminarWomen at MSRI lunch

Created on Feb 13, 2019 03:50 PM PST
20. SeminarPrismatic Cohomology: p-adic Tate twists and the odd vanishing conjecture for K-theory

Updated on May 07, 2019 02:34 PM PDT
21. SeminarFuture directions lectures: Simpson’s integrality conjecture and arithmetic loci

Updated on May 10, 2019 09:11 AM PDT
22. SeminarGraduate Student Seminar - Pre-talks:

Updated on May 10, 2019 03:13 PM PDT
23. SeminarBGMS Seminar: Gale duality, blowups and moduli spaces

Updated on May 09, 2019 01:10 PM PDT
24. SeminarFuture directions lectures: Using derived algebraic geometry

Updated on May 10, 2019 09:09 AM PDT
25. SeminarIrregular local systems working group: Stokes structures in dim 1 and higher

Updated on May 02, 2019 11:59 AM PDT
26. SeminarStudent Deformation Theory Seminar: L^2 theory for superpotentials and their Hochschild homology

Updated on May 03, 2019 08:40 AM PDT
27. SeminarAlgebraic Geometry Colloquium: o-minimal GAGA and applications to Hodge theory

Updated on Apr 30, 2019 08:48 AM PDT
28. SeminarDAG Learning Seminar: Tannaka duality

Updated on Apr 30, 2019 11:14 AM PDT
29. SeminarCommutative Algebra and Algebraic Geometry Seminar:

Created on Feb 27, 2019 10:03 AM PST
30. SeminarCombinatorics Seminar: LLT Polynomials, k-Schur Functions, and Positivity

Updated on Apr 29, 2019 03:31 PM PDT
There are more then 30 past seminars. Please go to Past seminars to see all past seminars.