Mathematical Sciences Research Institute

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1. GFA Main Seminar: Sidon Sets and Random Matrices

Location: MSRI: Simons Auditorium
Speakers: Gilles Pisier (Texas A & M University)

We will recall some of the classical theory of Sidon sets of characters on compact groups (Abelian or not), and its connections with Gaussian random variables. We will then give several recent extensions of the notions of Sidon set, randomly Sidon set and subgaussian sequence in bounded orthonormal systems, triggered by Bourgain and Lewko’s recent work. In the second part of the talk, non-commutative analogues will be discussed, involving Sidon subsets in the dual of compact non-Abelian groups. The case of matricial systems, analogous to Fourier-Peter-Weyl series on compact groups, connects the subject to Random Matrix Theory. Several open problems will be discussed. All relevant papers are currently available on arxiv.

Updated on Nov 13, 2017 03:15 PM PST
2. GFA Young Researchers Seminar: Gaussian concentration and random unconditional structure

Location: MSRI: Simons Auditorium
Speakers: Petros Valettas (University of Missouri)

The concentration of measure is a basic tool with various applications in geometric functional analysis. Unlike in the isomorphic theory, in the almost isometric context more delicate forms of it are required. In this talk we will discuss how one can take advantage of the linear structure of the normed space in order to establish almost optimal small deviation estimates for the corresponding norm. We will also present an application of the latter on estimates in Dvoretzky’s theorem. (Based on joint work with G. Paouris).

Updated on Nov 16, 2017 01:44 PM PST

Upcoming Seminars

Location: MSRI: Baker Board Room
Speakers: Mónica Blanco Gómez (University of Cantabria), Marcel Celaya (Georgia Institute of Technology)
Marcel Celaya, Assorted Topics on Matroids
Monica Blanco Gomez, Preparation for Spanning Lattice Polytopes and the Uniform Position Principle (Lukas Katthan)
Created on Aug 18, 2017 11:45 AM PDT
2. GTC Main Seminar: Spanning lattice polytopes and the Uniform position principle

Location: MSRI: Simons Auditorium
Speakers: Lukas Katthän (University of Minnesota)

A lattice polytope is called spanning (or primitive) if its lattice points affinely span the ambient lattice. This property can be translated to a natural algebraic property of the Ehrhart ring of the polytope.
In this talk, I will present recent joint work with Johannes Hofscheier and Benjamin Nill, where we use methods from commutative algebra and algebraic geometry to obtain new inequalities for the h^*-vector.
This extends our previous work on the absence of inner zeros in the h^*-vector, as well as Hibi's inequality for polytopes with inner lattice points.

Updated on Oct 30, 2017 11:24 AM PDT
3. GFA Main Seminar

Location: MSRI: Simons Auditorium
Created on Aug 18, 2017 11:53 AM PDT
4. GFA Main Seminar

Location: MSRI: Simons Auditorium
Created on Aug 18, 2017 11:53 AM PDT
5. GFA Young Researchers Seminar: Iterative Methods for Solving Factorized Linear Systems

Location: MSRI: Baker Board Room
Speakers: Anna Ma (Claremont Graduate University)
Stochastic iterative algorithms such as the Kacmarz and Gauss-Seidel methods have gained recent attention because of their speed, simplicity, and the ability to approximately solve large-scale linear systems of equations without needing to access the entire matrix. In this work, we consider the setting where we wish to solve a linear system in a large matrix $X$ that is stored in a factorized form, $X = UV$; this setting either arises naturally in many applications or may be imposed when working with large low-rank datasets for reasons of space required for storage. We propose a variant of the randomized Kaczmarz method for such systems that takes advantage of the factored form, and avoids computing $X$. We prove an exponential convergence rate and supplement our theoretical guarantees with experimental evidence demonstrating that the factored variant yields significant acceleration in convergence. Joint work with Deanna Needell and Aaditya Ramdas.
Updated on Nov 22, 2017 08:41 AM PST
6. GTC Visions Seminar: Continuous Matroids revisited

Location: Space Science Lab, Room 105
Speakers: Anders Björner (Royal Institute of Technology (KTH))

There are several analogies between discrete and continuous mathematics that influence our thinking and understanding. For a very basic example, take the the Boolean lattice of subsets of a finite set with its continuous analog the measurable subsets of the unit interval.
A general setting for such analogs, suggested by matroid theory and inspired by von Neumann’s work on "continuous geometries" from 1936, will be discussed. It is based on work from the 1980’s, much of it joint with L. Lovász, on continuous matroids, including continuous analogs of partitions and of field extensions.

Updated on Nov 22, 2017 02:03 PM PST
7. GFA Main Seminar

Location: Space Science Lab, Room 105
Updated on Nov 22, 2017 08:44 AM PST
8. GFA Main Seminar

Location: Space Science Lab, Room 105
Updated on Nov 22, 2017 08:44 AM PST
9. UC Berkeley Colloquium: Algebraic Structures on Polytopes

Location: 60 Evans Hall
Speakers: Federico Ardila (San Francisco State University)

http://events.berkeley.edu/index.php/calendar/sn/math.html?event_ID=113270

Generalized permutahedra are a beautiful family of polytopes with a rich combinatorial structure and strong connections to optimization. We study their algebraic structure: we prove they are the universal family of polyhedra with a certain “Hopf monoid" structure. This construction provides a unifying framework to organize and study many combinatorial families:
1. It uniformly answers open questions and recovers known results about graphs, posets, matroids, hypergraphs, and simplicial complexes.
2. It reveals that three combinatorial reciprocity theorems of Stanley and Billera–Jia–Reiner on graphs, posets, and matroids are really the same theorem.
3. It shows that permutahedra and associahedra “know" how to compute the multiplicative and compositional inverses of power series.
The talk will be accessible to undergraduates and will not assume previous knowledge of these topics.

Updated on Nov 20, 2017 12:10 PM PST

Location: MSRI: Baker Board Room
Created on Aug 18, 2017 11:45 AM PDT
11. GTC Main Seminar: On the treewidth of triangulated three-manifolds

Location: MSRI: Simons Auditorium
Speakers: Jonathan Spreer (Freie Universität Berlin)

In graph theory, as well as three-manifold topology, a wide range of parameters exist to decide how "simple", or "thin", a given graph or three-manifold is. These width-type parameters, such as pathwidth or treewidth for graphs, or the concept of thin position for three-manifolds, play an important role when studying algorithmic problems in the field: There exist several topological problems -- some of them known to be computationally hard in general -- which become solvable in polynomial time as soon as the dual graph of the input triangulation has bounded treewidth.
In view of such algorithmic results, the question of whether there exists an explicit link between combinatorial concepts such as treewidth (applicable to a single input triangulation of a given three-manifold M) and results in three-manifold topology (applicable to all possible triangulations of M) has repeatedly been asked by researchers working in the computational branch of three-manifold topology.
In this talk I will present such a link, stating that there exist families of three-manifolds not admitting triangulations of bounded treewidth.

Updated on Nov 01, 2017 09:18 AM PDT
12. GFA Main Seminar

Location: MSRI: Simons Auditorium
Created on Aug 18, 2017 11:53 AM PDT
13. Combinatorial Fixed Point Theorems Working Group

Location: MSRI: Baker Board Room
Created on Aug 30, 2017 11:45 AM PDT
14. GFA Main Seminar

Location: MSRI: Simons Auditorium
Created on Aug 18, 2017 11:53 AM PDT
15. GTC Main Seminar

Location: MSRI: Simons Auditorium
Created on Aug 18, 2017 11:50 AM PDT
16. GFA Young Researchers Seminar

Location: MSRI: Simons Auditorium
Updated on Sep 01, 2017 01:05 PM PDT
17. GTC Visions Seminar

Location: MSRI: Simons Auditorium
Updated on Sep 28, 2017 08:50 AM PDT
18. GFA Main Seminar: Pisier's cotype dichotomy problem revisited

Location: MSRI: Simons Auditorium
Speakers: Gideon Schechtman (Weizmann Institute of Science)

In an effort to renew interest in the dichotomy problem, I'll survey what is known and in particular tell you about an old/new result of Nicole Tomczak-Jaegermann and myself along the lines of a result of Bourgain but with some improvement. This gives the best known estimate concerning the dichotomy problem . I'll also try to suggest what should be done next.

Updated on Nov 20, 2017 09:11 AM PST
19. GFA Main Seminar: Pisier's cotype dichotomy problem revisited

Location: MSRI: Simons Auditorium
Speakers: Gideon Schechtman (Weizmann Institute of Science)

In an effort to renew interest in the dichotomy problem, I'll survey what is known and in particular tell you about an old/new result of Nicole Tomczak-Jaegermann and myself along the lines of a result of Bourgain but with some improvement. This gives the best known estimate concerning the dichotomy problem . I'll also try to suggest what should be done next.

Updated on Nov 20, 2017 09:11 AM PST
20. Lattice Points Working Group

Location: MSRI: Baker Board Room
Updated on Oct 26, 2017 03:50 PM PDT
21. GFA Postdoc Seminar

Location: MSRI: Simons Auditorium
Created on Aug 21, 2017 09:21 AM PDT
22. GTC Postdoc Seminar

Location: MSRI: Simons Auditorium
Created on Aug 21, 2017 09:22 AM PDT

Location: MSRI: Baker Board Room
Created on Aug 18, 2017 11:45 AM PDT
24. GTC Main Seminar

Location: MSRI: Simons Auditorium
Updated on Nov 01, 2017 09:18 AM PDT
25. GFA Main Seminar

Location: MSRI: Simons Auditorium
Created on Aug 18, 2017 11:53 AM PDT
26. Combinatorial Fixed Point Theorems Working Group

Location: MSRI: Baker Board Room
Created on Aug 30, 2017 11:45 AM PDT
27. GFA Main Seminar

Location: MSRI: Simons Auditorium
Created on Aug 18, 2017 11:53 AM PDT
28. GTC Main Seminar

Location: MSRI: Simons Auditorium
Created on Aug 18, 2017 11:50 AM PDT
29. GFA Young Researchers Seminar

Location: MSRI: Simons Auditorium
Updated on Sep 01, 2017 01:06 PM PDT
30. GTC Visions Seminar

Location: MSRI: Simons Auditorium
Updated on Sep 28, 2017 08:50 AM PDT
31. GFA Main Seminar

Location: MSRI: Simons Auditorium
Created on Aug 18, 2017 11:59 AM PDT
32. GFA Main Seminar

Location: MSRI: Simons Auditorium
Created on Aug 18, 2017 11:58 AM PDT
33. Lattice Points Working Group

Location: MSRI: Baker Board Room
Updated on Oct 26, 2017 03:51 PM PDT
34. GFA Postdoc Seminar

Location: MSRI: Simons Auditorium
Created on Aug 21, 2017 09:21 AM PDT
35. GTC Postdoc Seminar

Location: MSRI: Simons Auditorium
Created on Aug 21, 2017 09:22 AM PDT
36. The Bowen Lectures

Location: UC Berkeley
Speakers: Avi Wigderson
Created on Aug 21, 2017 02:36 PM PDT
37. The Bowen Lectures

Location: UC Berkeley
Speakers: Avi Wigderson
Created on Aug 21, 2017 02:36 PM PDT
38. The Bowen Lectures

Location: UC Berkeley
Speakers: Avi Wigderson
Created on Aug 21, 2017 02:36 PM PDT
39. Seminar Sequence

Location: MSRI: Simons Auditorium
Created on Aug 31, 2017 03:27 PM PDT

1. SeminarTwo Famous Betting Systems

Updated on Nov 21, 2017 11:00 AM PST
2. SeminarGFA Main Seminar: Sidon Sets and Random Matrices

Updated on Nov 13, 2017 03:15 PM PST
3. SeminarGTC Main Seminar: On the Topology of Steel

Updated on Oct 30, 2017 11:22 AM PDT

Created on Aug 18, 2017 11:45 AM PDT
5. SeminarLattice Points Working Group: Lattice points on Convex Bodies

Updated on Nov 15, 2017 08:43 AM PST
6. SeminarUC Berkeley Colloquium: What is quantum chaos?

Updated on Nov 09, 2017 08:52 AM PST
7. SeminarUC Berkeley Colloquium: The Global Histories of Mathematics

Updated on Nov 02, 2017 01:42 PM PDT
8. SeminarGFA Main Seminar: Borell’s formula and applications

Updated on Nov 03, 2017 11:16 AM PDT
9. SeminarGFA Main Seminar: Borell’s formula and applications

Updated on Nov 03, 2017 11:15 AM PDT
10. SeminarGFA Young Researchers Seminar: Hadamard spaces are not coarsely universal

Updated on Nov 02, 2017 12:54 PM PDT
11. SeminarGFA Main Seminar: Around the Restricted Isometry Property

Updated on Nov 03, 2017 11:15 AM PDT
12. SeminarGFA Main Seminar: Asymptotics in Sequences Comparisons

Updated on Nov 03, 2017 11:15 AM PDT
13. SeminarGTC Main Seminar: What I did at MSRI

Updated on Oct 23, 2017 08:52 AM PDT
14. SeminarGTC Graduate Seminar: The minimum Euclidean-norm point in a convex polytope: Wolfe’s combinatorial algorithm is exponential

Updated on Nov 02, 2017 10:19 AM PDT
15. SeminarGTC Postdoc Seminar: Weakly inscribed polyhedra

Updated on Nov 01, 2017 03:29 PM PDT
16. SeminarGFA Postdoc Seminar: Spectral gap of random graphs

Updated on Nov 02, 2017 01:40 PM PDT
17. SeminarGTC Postdoc Seminar: The rigidity theory of frameworks of polytopes

Updated on Oct 25, 2017 02:44 PM PDT
18. SeminarGFA Postdoc Seminar: Unique determination of convex lattice set

Updated on Oct 27, 2017 02:32 PM PDT
19. SeminarLattice Points Working group: discussion of Hilbert bases of cones

Updated on Oct 27, 2017 02:13 PM PDT
20. SeminarUC Berkeley Colloquium: Serge Lang Undergraduate Lecture: When the precision of mathematics meets the messiness of the world of people

Updated on Sep 29, 2017 09:54 AM PDT
21. SeminarGFA Main Seminar: Gaussian-width complexity of functions on the discrete cube and mean-field behavior of random graphs and interacting particle systems

Updated on Oct 26, 2017 03:49 PM PDT
22. SeminarGFA Main Seminar: Gaussian-width complexity of functions on the discrete cube and mean-field behavior of random graphs and interacting particle systems

Updated on Oct 26, 2017 03:49 PM PDT
23. SeminarGTC Visions Seminar: Matroids and valuations

Updated on Oct 26, 2017 12:27 PM PDT
24. SeminarGFA Young Researchers Seminar: Extremal sections of cross-polytope

Updated on Oct 26, 2017 08:37 AM PDT
25. SeminarGFA Main Seminar: Gaussian-width complexity of functions on the discrete cube and mean-field behavior of random graphs and interacting particle systems

Updated on Oct 26, 2017 03:49 PM PDT
26. SeminarMathematical Research Culture Seminar

Created on Sep 14, 2017 09:37 AM PDT
27. SeminarGFA Main Seminar: Gaussian-width complexity of functions on the discrete cube and mean-field behavior of random graphs and interacting particle systems

Updated on Oct 26, 2017 03:48 PM PDT
28. SeminarGTC Main Seminar: Discrete slicing problems

Updated on Oct 16, 2017 01:18 PM PDT
29. SeminarGTC Graduate Seminar: Software tool demonstrations

Updated on Oct 27, 2017 08:43 AM PDT
30. SeminarWriting Seminar

Created on Oct 04, 2017 03:29 PM PDT
There are more then 30 past seminars. Please go to Past seminars to see all past seminars.