Chaire CIMI : J.M. Landsberg

26 April

Chaire CIMI : J.M. Landsberg

Professor Joseph M. Landsberg



Joseph M. Landsberg works on questions at the interface of algebraic geometry, differential geometry and representation theory. His current research is focused on geometric problems originating in complexity theory. Landsberg obtained his PhD in 1990 from Duke University under the direction of Robert Bryant. He was Maître de Conférences at Paul Sabatier University from 1996 to 2000, and he is Professor at Texas A&M University  since  2004.
He has directed twelve PhD theses. He is the author of over eighty research articles and several textbooks, including "Geometry and complexity theory" (Cambridge 2017) and "Tensors: Geometry and Applications" (AMS 2012).


Colloquium CIMI


13th May 2022 at 02:00 pm, salle du conseil (bâtiment administratif de l'UPS)

Géométrie algébrique et complexité.

Résumé: L'informatique a motivé des nouvelles questions de géométrie algébrique et de théorie des représentations. Dans cet exposé, je discuterai du problème de la complexité de la multiplication des matrices. Les informaticiens ont conjecturé que pour n très grand, il est presque aussi facile de multiplier des matrices nxn que de  les ajouter ! Je présenterai l'histoire du problème et ses développements récents.


Lectures on Introduction to classical and quantum information theory


As part of his CIMI Excellence Chair, J.M. Landsberg will give a mini-course entitled "Introduction to classical and quantum information theory". This 18-hour course is intended to be widely accessible. It will be held in the Johnson room (1st floor, building 1R3) on Tuesdays and Thursdays from 15:30 to 17:00. The first session will take place on Tuesday 29 March and will give a general presentation of the course content, which is summarised below.

This course will cover classical information theory, quantum information theory and uses of representation theory in quantum information theory.
No prior knowledge of anything quantum will be assumed. Notes will be distributed.

In more detail, the topics that will be covered are:
 Classical information theory:
   Data compression: noiseless channels
   Entropy, i.e., uncertainty
   Shannon’s noiseless channel theorem
   Transmission over noisy channels

 Quantum information:
   Laws  of quantum mechanics and first consequences
   Distances in the classical and quantum settings
   The quantum noiseless channel theorem
   Properties of von Neumann entropy
   Conditional von Neumann entropy and strong subadditivity
   Entanglement and LOCC

 Representation theory and Quantum information:
   Basics of Representation theory
   Schur-Weyl duality and ε-typical subspaces
   The quantum marginal problem
   Tripartite States

The lectures notes are available here