# Analysis & Probability Seminar at Chalmers / GU

The seminar is joint for the division of Analysis and Probability within the Department of Mathematics at Chalmers / GU. Its main themes include: Probability Theory, Mathematical Physics, Operator Algebras and Harmonic and Functional Analysis.

Should you have any questions or suggestions, feel free to email one of the organizers Jakob Björnberg (jakobbj 'at' chalmers.se), Simon Larson (larsons 'at' chalmers.se) or Eduard Vilalta (vilalta 'at' chalmers.se).

Instructions for invited speakers:

The seminar caters to a broad audience in analysis and probability. We thus urge speakers to make the first 10-15 minutes of the talk very introductory, aimed at first-year graduate students. The total time for the seminar is 50 minutes plus 10 minutes for questions.

Coming seminars

2024-09-10 at 13:15, MVL14

Hannes Thiel (Chalmers/GU)

Pure C*-algebras

In his seminal investigation of Z-stability for simple, nuclear C*-algebras, Winter introduced the notion of (m,n)-pureness with m and n quantifying comparison and divisibility properties in the Cuntz semigroup, and he showed that every simple C*-algebra that has locally finite nuclear dimension and that is (m,n)-pure for some m and n is Z-stable. Combined with the result of Roerdam that every Z-stable C*-algebra is pure (that is, (0,0)-pure, which means that its Cuntz semigroup has the strongest comparison and divisibility properties), this provides a situation where (m,n)-pureness implies pureness.

In a recent paper with R. Antoine, F. Perera and L. Robert, we removed the assumption of locally finite nuclear dimension and showed that every simple, (m,n)-pure C*-algebra is pure. In this work we generalize the result even further by showing that (m,n)-pureness implies pureness in general.

As an application we show that every C*-algebra with the Global Glimm Property and finite nuclear dimension is pure.

This is joint work with R. Antoine, F. Perera, and E. Vilalta

2024-09-17 at 13:15, MVL14

Cécile Mailler (Bath, UK)

A two-table theorem for a disordered version of the Chinese restaurant process (CRP)

In this joint work with Jakob Björnberg, Peter Mörters and Daniel Ueltschi, we introduce a disordered version of the CRP in which tables have different weights (or fitnesses). When a new customer enters the restaurant, they choose to open a new table with probability proportional to a parameter $\theta$, or they sit at an occupied table with probability proportional to the weight of this table times the number of customers already sitting at this table. We show that, in this model, in probability, a proportion converging to one of all customers sit at the largest table. We also show that this is not true almost surely, but prove instead that, almost surely, a proportion converging to one of all customers sit at one of the two largest tables.

2024-09-19 at 13:15, MVL14 (extra seminar, unusual day)

Andreas Rosén (Chalmers / GU)

Coerciveness and Morrey inequalities for elliptic operators with natural boundary conditions via Weitzenböck identities

We prove a Weitzenböck identity for general pairs of constant-coefficient homogeneous first-order partial differential operators, and deduce from it sufficient algebraic conditions for coerciveness and Morrey estimates under the natural 1/2 boundary conditions. Our proof of the $W^{1,2}$ elliptic estimate relies on the Aronszajn-Ne{\u c}as-Smith coercive estimate. For generalized strongly pseudoconvex domains, we improve the Morrey estimate to a weighted $W^{1,2}$ square function estimate, using a generalized Cauchy--Pompeiu reproducing formula and the $T1$ theorem for singular integrals. We use Van Schaftingen's notion of cocanceling to study the generalized Levi forms appearing. This is joint work with Erik Duse, FOI.

2024-09-24 at 13:15, MVL14

Jonathan Breuer (Hebrew University of Jerusalem / Mittag-Leffler)

Towards a Floquet Theory for Periodic Jacobi Matrices on Trees

Periodic Jacobi matrices on the line have a very rich spectral theory, one of whose ingredients is the Floquet theory of eigenfunctions. In this talk we will discuss ongoing work that attempts to generalize this theory to more general trees. We will describe some results obtained in joint works with Jess Banks, Jorge Garza Vargas, Eyal Seelig and Barry Simon.

2024-10-15 at 13:15, MVL14

Tomas Berggren (MIT, USA / Mittag-Leffler)

TBA

2024-10-22 at 13:15, MVL15 (note unusual room)

Emilie Elkiær (Oslo)

TBA

2024-11-05 at 13:15, MVL14

Alexander Müller-Hermes (Oslo)

TBA

2024-11-12 at 13:15, MVL14

Alistair Miller (SDU, Denmark)

TBA

2024-11-19 at 13:15, MVL14

Terry Soo (UCL, UK)

TBA

2024-11-20 at 13:15, MVL15 -- NOTE UNUSUAL DAY (Wednesday) and room

Fatma Ayça Cetinkaya (Mersin University, Turkey)

TBA

2024-11-26 at 13:15, MVL14

Mathias Palmstrøm (NTNU, Norway)

TBA

Previous seminars

2024-01-23 at 13:15, MVL14

Ulrik Enstad (Oslo)

Classifiability of C*-algebras associated with point sets

2024-01-30 at 13:15, MVL14

Pieter Spaas (Copenhagen)

Local Hilbert-Schmidt stability

2024-02-07 at 13:15, MVL15 -- NOTE UNUSUAL DAY & PLACE

Lashi Bandara (Deakin University, Melbourne)

Trace, Regularity, Fredholmness: the story of non-compact boundary for first-order elliptic operators

2024-02-13 at 13:15, MVL14

Johan Wästlund (Chalmers/GU)

Billiards, Checkers, and Quadratic Reciprocity

2024-02-20 at 13:15, MVL14

Shrish Parmeshwar (Warwick, UK)

Global-in-time Vortex Configurations for the 2D Euler Equations

2024-02-27 at 13:15, MVL14

Eduard Vilalta (Chalmers/GU)

Nowhere scattered multiplier algebras

2024-03-05 at 13:15, MVL14

Are Austad (Syddansk Universitet, Odense)

Ideal intersection properties for group-graded Banach *-algebras

2024-03-12 at 13:15, MVL14

Peter Sjögren (Chalmers/GU)

Variation inequalities for the Ornstein-Uhlenbeck semigroup

2024-03-14 at 13:15, MVL14 -- NOTE UNUSUAL DAY (Thursday)

Erik Duse (KTH)

Generic ill-posedness of the energy-momentum equations in the vectorial calculus of variations

2024-03-20 at 13:15, MVL15 -- NOTE UNUSUAL DAY (Wednesday)

Tobias Weich (Paderborn)

Polyhedral bounds on the joint spectrum on higher rank locally symmetric spaces

2024-04-02 at 13:15, MVL14

Malin Palö Forsström (Chalmers/GU)

Poisson coverage processes

2024-04-10 at 13:15, MVL15 -- NOTE UNUSUAL DAY (Wednesday)

David Rule (Linköping)

Multilinear and Weighted Estimates for Oscillatory Integral Operators

2024-04-16 at 13:15, MVL14

Eric Ling (Copenhagen)

Rigidity aspects of Penrose's singularity theorem

2024-04-23 at 13:15, MVL14

Håkan Andreasson (Chalmers/GU)

Existence of a minimizer to the particle number-Casimir functional for the Einstein-Vlasov system

2024-04-30 at 13:15, MVL14

Robin van Haastrecht (Chalmers/GU)

Limit formulas for the trace of the functional calculus of quantum channels for $SU(2)$

2024-05-07 at 13:15, MVL14

Søren Fournais (Copenhagen)

On the ground state energy of the dilute Bose gas

2024-05-21 at 13:15, MVL14

Hedong Hou (Laboratoire de Mathématiques d'Orsay, Université Paris-Saclay)

Well-posedness for parabolic Cauchy problems with distributional initial data

2024-05-28 at 13:15, MVL14

Wojciech Szymanski (Syddansk Universitet)

Cuntz algebras and the Thompson groups

2024-05-28 at 15:15, MVL14 (EXTRA SEMINAR, UNUSUAL TIME)

Frank Thuijsman (Maastricht University)

Game Theory, from John von Neumann to Treatment of Cancer

2024-05-29 at 15:15, MVL14 (EXTRA SEMINAR, UNUSUAL TIME)

Alessandro Bravetti (Universidad Nacional Autónoma de México)

From Fisher to Fisher: using Fisher information to understand Fisher's Fundamental Theorem of Natural Selection

2024-06-11 at 13:15, MVL14

Jorge Castillejos (UNAM, Cuernavaca)

2024-06-11 at 14:30, MVL14 (EXTRA SEMINAR, UNUSUAL TIME)

Mizanur Rahaman (ENS, Lyon)

Quantum Stein's Lemma and subalgebra entropies

2024-06-18 at 13:15, MVL14

Leif Arkeryd (Chalmers/GU)

On Boltzmann type equations with discrete velocities

2024-08-27 at 13:15, MVF23 (note unusual room)

Khalid Koufany (Université de Lorraine, Nancy, France)

A characterization of the $L^2$-range of the generalized spectral projections related to the Hodge-de Rham Laplacian