Seminar: From Random Matrices to Random Tensors

Organisation: Dr. Johannes Thürigen

Tuesday 2pm, Room SR4, LSF

Random matrices are used for the statistical analysis of large samples but find also application in various fields of physics. In particular they became of interest around 1990 in string theory as a theory of random surfaces and 2d quantum gravity. Indeed they generate the Brownian sphere as recently proven rigorously. From this perspective it is a natural question whether these results generalize to dimension d>2 and over the last 10 years this was accomplished generalizing from matrices to tensors. In this seminar we will review first the main results of matrix models with a special focus on their combinatorics, the surface topologies they generate and the geometries at criticality. We will then study how these results generalize to tensors with a specific U(N) invariance both from a perturbative as well as a constructive perspective. We will look furthermore at its physics interpretation as a field theory of space(time), its critical behaviour and the possibility of a phase transition from discrete to continuum due to symmetry breaking.

Schedule

Date Speaker Title
10/08 Johannes Thürigen Overview
10/29 Alex Hock Random matrices
11/05 Johannes Thürigen Tensor invariants and simplicial pseudo-manifolds
11/12 Alex Stottmeister The Brownian map and Liouville gravity
12/03 Johannes Thürigen The continuous random tree and melonic manifolds
12/10 Romain Pascalie Constructive results in the quartic model
12/17 Johannes Thürigen Algebraic perspective on the Dyson-Schwinger equations
02/18 Luca Lionni Scaling limits of random graphs and a proposal for random geometry in dimension higher than two

Literature

  • R. Gurau (2017): Random tensors
  • T. Tao (2012): Topics in random matrix theory
  • G.W. Anderson, A. Guionnet, O. Zeitouni (2010): An introduction to random matrices
  • P. Di Francesco, P. Ginsparg, J. Zinn-Justin (1995): 2D gravity and random matrices