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All Colloquia & Seminars

  1. Geometry and Analysis of Surface Group Representations: Introduction to Spectral Networks (II)

    Location: MSRI: Baker Board Room
    Speakers: Daniele Alessandrini (Ruprecht-Karls-Universität Heidelberg)

    I will give an introduction to the theory of Spectral Networks, developed by Gaiotto, Moore and Neitzke during their research about supersymmetry. 

    These objects have an independent interest for mathematicians, mostly in the theory of surfaces. They can be described as combinatorical objects on the surface, or, equivalently as some orbits associated to a conformal structure on the surface and a collection of holomorphic differentials.

    The main focus will be on how to use these objects to give coordinates on the moduli spaces of representations of surface groups. These coordinates generalise Fenchel-Nielsen coordinates and Fock-Goncharov coordinates in an especially intriguing way.

    Updated on Mar 26, 2015 04:16 PM PDT
  2. Lorentzian geometric structures seminar: Margulis spacetimes and contracting deformations of hyperbolic surfaces II

    Location: MSRI: Baker Board Room
    Speakers: Jeffrey Danciger (University of Texas)

    This second talk will go into more details of the proof.

    We will describe a properness criterion for free groups acting by isometries of Minkowski 3-space in terms of the deformation theory of hyperbolic surfaces. A corollary of the criterion is that every Margulis spacetime fibers in lines over a hyperbolic surface.


    We will discuss some details of the proof, including the case in which the linear part has parabolics. This talk is based on joint work with François Guéritaud and Fanny Kassel.

    Updated on Mar 26, 2015 03:39 PM PDT
  1. DMS Research Seminar: Renormalized volume, Weil-Petersson geometry and volumes of hyperbolic 3-manifolds that fiber over the circle

    Location: MSRI: Simons Auditorium
    Speakers: Jeffrey Brock (Brown University), Kenneth Bromberg (University of Utah)

    The notion of "renormalized volume" gives a way to assign a finite volume to an infinite volume hyperbolic 3-manifold. Krasnov and Schlenker showed (following a similar result for Schottky space by Takhtjan-Teo) that the renormalized volume on a Bers slice gives a potential for the Weil-Petersson metric on Teichmüller space - Schlenker, in turn, used this idea to give an effective version of bounds due to Brock on the volume of the convex core of quasifuchsian manifolds in terms the Weil-Petersson distance between the two components of the conformal boundary. Kojima-McShane connected Schlenker's idea to volumes of hyperbolic 3-manifolds that fiber of the circle and the normalized entropy on pseudo-Anosov mapping class (Teichmüller translation length). We discuss a proof of improved bounds (originally due to Brock) in terms of the Weil-Petersson translation length to volumes of mapping tori as well as new implications for the length spectrum and systolic geometry of moduli space with the Weil-Petersson metric.  We will give an elementary overview and introduction to the above, with a particular emphasis on new results on the geometry of the Weil-Petersson metric.

    Updated on Mar 27, 2015 03:36 PM PDT
  2. DMS Postdoc Seminar: Coupled Hitchin Equations

    Location: MSRI: Simons Auditorium
    Speakers: Qiongling Li (Rice University)

    In this talk, I will talk about a technical part in the joint paper with Brian Collier about studying asymptotic behavior of Hitchin representations in terms of Higgs bundles. This technical part estimates the asymptotic solution of the coupled Hitchin equations. I will also discuss how the analysis is related to geometry of frames.

    Updated on Mar 26, 2015 04:14 PM PDT
  3. GAAHD Postdoc Seminar: The stable type of the mapping class group and some relatively hyperbolic groups and applications to pointwise ergodic averages

    Location: MSRI: Simons Auditorium
    Speakers: Ilya Gekhtman (Yale University)

    The stable ratio set of a nonsingular action is a notion introduced by Bowen and Nevo to prove pointwise ergodic theorems for measure preserving actions of certain nonamenable groups.


    I  prove that stable ratio set of the action of a discrete subgroup of isometries of a CAT(-1) space with finite Bowen-Margulis measure on its boundary with the Patterson-Sullivan measure has numbers other than 0, 1 and \infinity, extending techniques of Bowen from the setting of hyperbolic groups.


    I also prove the same result for the action of the mapping class group on the sphere of projective measured foliations with the Thurston measure, using some "statistical hyperbolicity" properties for the (non hyperbolic) Teichmueller metric on Teichmueller space.

    Updated on Mar 26, 2015 03:44 PM PDT
  4. MSRI Evans Talk: Dynamics on moduli spaces of flat surfaces - questions and new directions

    Location: 60 Evans Hall
    Speakers: Maryam Mirzakhani (Stanford University)
    In this talk, we will discuss various basic problems regarding the topology, geometry and dynamical systems on surfaces: all these questions are closely related to the study of closed Riemann surfaces endowed with a holomorphic one-form. This is the same as having a flat metric on the surface with finitely many cone-type singularities.
     
    The moduli space of holomorphic one-forms on a closed surface of genus $g$ has a natural piecewise linear structure and carries an action of GL(2,R).
    One can investigate the geometry and dynamics of an individual flat surface by studying its orbit under this linear group action. 
     
    One famous example is how understanding a billiard path on a rational billiard is related to studying the orbits of the action of GL(2,R) on the moduli spaces of flat surfaces. 
     
    Many of the results in this area are motivated by statements in homogenous dynamics. On the other hand, they have strong connections with other topics in algebraic geometry and number theory. In this talk, I will give an overview of some known results and open questions regarding these moduli spaces.
    Updated on Mar 30, 2015 12:00 PM PDT
  5. GAAHD Research Seminar

    Location: MSRI: Simons Auditorium
    Updated on Feb 20, 2015 09:47 AM PST
  6. 3-Manifold Seminar

    Location: 939 Evans Hall
    Speakers: Ian Agol (University of California, Berkeley)
    The topic this semester is representations of 3-manifold groups into SL_2 C. Topics will include:
     
    - character varieties and curves of characters
    - ideal points, R-tree actions, tree actions associated to ideal points of curves
    - associating incompressible surfaces to tree actions and measured laminations to R-tree actions
    - volumes of representations and Chern-Simons invariant
    - Dehn invariants, the Bloch group, and extensions
    - volume rigidity, via simplicial volume and the barycenter map
    - the A-polynomial 
     
    Created on Jan 29, 2015 09:26 AM PST
  7. Open ended seminar

    Location: MSRI: Baker Board Room
    Updated on Mar 06, 2015 09:52 AM PST
  8. DMS Research Seminar

    Location: MSRI: Simons Auditorium
    Speakers: Marc Burger (Eidgenössische TH Zürich-Hönggerberg), Fanny Kassel (Université de Lille I (Sciences et Techniques de Lille Flandres Artois))
    Updated on Jan 28, 2015 02:17 PM PST
  9. GAAHD Research Seminar

    Location: MSRI: Simons Auditorium
    Updated on Feb 20, 2015 09:49 AM PST
  10. 3-Manifold Seminar

    Location: 939 Evans Hall
    Speakers: Ian Agol (University of California, Berkeley)
    The topic this semester is representations of 3-manifold groups into SL_2 C. Topics will include:
     
    - character varieties and curves of characters
    - ideal points, R-tree actions, tree actions associated to ideal points of curves
    - associating incompressible surfaces to tree actions and measured laminations to R-tree actions
    - volumes of representations and Chern-Simons invariant
    - Dehn invariants, the Bloch group, and extensions
    - volume rigidity, via simplicial volume and the barycenter map
    - the A-polynomial 
     
    Created on Jan 29, 2015 09:28 AM PST
  11. Open ended seminar

    Location: MSRI: Baker Board Room
    Updated on Mar 06, 2015 09:52 AM PST
  12. DMS Research Seminar

    Location: MSRI: Simons Auditorium
    Speakers: Marc Burger (Eidgenössische TH Zürich-Hönggerberg), Fanny Kassel (Université de Lille I (Sciences et Techniques de Lille Flandres Artois))
    Updated on Jan 28, 2015 02:16 PM PST
  13. MSRI Evans Talk

    Location: 60 Evans Hall
    Speakers: Hee Oh (Yale University)
    Updated on Jan 15, 2015 09:42 AM PST
  14. GAAHD Research Seminar

    Location: MSRI: Simons Auditorium
    Updated on Feb 20, 2015 09:49 AM PST
  15. 3-Manifold Seminar

    Location: 939 Evans Hall
    Speakers: Ian Agol (University of California, Berkeley)
    The topic this semester is representations of 3-manifold groups into SL_2 C. Topics will include:
     
    - character varieties and curves of characters
    - ideal points, R-tree actions, tree actions associated to ideal points of curves
    - associating incompressible surfaces to tree actions and measured laminations to R-tree actions
    - volumes of representations and Chern-Simons invariant
    - Dehn invariants, the Bloch group, and extensions
    - volume rigidity, via simplicial volume and the barycenter map
    - the A-polynomial 
     
    Created on Jan 29, 2015 09:29 AM PST
  16. Open ended seminar

    Location: MSRI: Baker Board Room
    Updated on Mar 06, 2015 09:51 AM PST
  17. DMS Research Seminar

    Location: MSRI: Simons Auditorium
    Speakers: Marc Burger (Eidgenössische TH Zürich-Hönggerberg), Fanny Kassel (Université de Lille I (Sciences et Techniques de Lille Flandres Artois))
    Updated on Jan 28, 2015 02:15 PM PST
  18. GAAHD Research Seminar

    Location: MSRI: Simons Auditorium
    Updated on Feb 20, 2015 09:50 AM PST
  19. Open ended seminar

    Location: MSRI: Baker Board Room
    Updated on Mar 06, 2015 09:51 AM PST
  20. DMS Research Seminar

    Location: MSRI: Simons Auditorium
    Speakers: Marc Burger (Eidgenössische TH Zürich-Hönggerberg), Fanny Kassel (Université de Lille I (Sciences et Techniques de Lille Flandres Artois))
    Updated on Jan 28, 2015 02:15 PM PST
  21. GAAHD Research Seminar

    Location: MSRI: Simons Auditorium
    Updated on Feb 20, 2015 09:52 AM PST
  22. Open ended seminar

    Location: MSRI: Baker Board Room
    Updated on Mar 06, 2015 09:50 AM PST
  23. DMS Research Seminar

    Location: MSRI: Simons Auditorium
    Speakers: Marc Burger (Eidgenössische TH Zürich-Hönggerberg), Fanny Kassel (Université de Lille I (Sciences et Techniques de Lille Flandres Artois))
    Updated on Jan 28, 2015 02:14 PM PST

Past Seminars

seminar
  1. Seminar 3-Manifold Seminar

    Created on Jan 29, 2015 09:25 AM PST
  2. Seminar Minicourse

    Created on Mar 23, 2015 09:57 AM PDT
  3. Seminar Minicourse

    Created on Feb 23, 2015 10:43 AM PST
  4. Seminar 3-Manifold Seminar

    Created on Jan 29, 2015 09:23 AM PST
  5. Seminar Minicourse

    Created on Feb 23, 2015 10:40 AM PST
  6. Seminar 3-Manifold Seminar

    Created on Jan 29, 2015 09:22 AM PST
  7. Seminar Women in Science

    Updated on Feb 05, 2015 12:10 PM PST
  8. Seminar Minicourse

    Updated on Feb 23, 2015 10:37 AM PST
  9. Seminar 3-Manifold Seminar

    Created on Jan 29, 2015 09:21 AM PST
There are more then 30 past seminars. Please go to Past seminars to see all past seminars.