Laboratoire de Physique
Theorique d'Orsay

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Bâtiment 210
Univ. Paris-Sud 11
91405 Orsay Cedex
T. 01 69 15 63 53
F. 01 69 15 82 87

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Mathematical Physics Seminars 2017-2018

Les séminaires se tiennent en salle 114 au 1er étage du bâtiment 210.

Seminars are held in room 114, 1st floor of building 210.

Upcoming seminars

-  Friday 17 November 2017, 14:00, room 114

Goffredo Chirco (AEI, Potsdam) : Holographic entanglement entropy from random tensor networks via group field theory

We investigate the use of tensor networks techniques and quantum information theory for the study of the entanglement properties of quantum geometry states. In the language of the group field theory, we describe spin network states as quantum many-body systems. The very connectivity of such states, encoded in the links of the underlying graphs, is associated with the entanglement between the fundamental quanta constituting them. We establish a dictionary between group field theory states and (generalised) random tensor networks. With such a dictionary at hand, we target the calculation of the Ryu-Takayanagi formula for the entanglement entropy in the quantum gravity formalism of group field theory.

Past seminars

-  Wednesday 15 November 2017, 14:00, room 114

Rina Štrajn, Ruđer Bošković Institute, Division of Theoretical Physics, Zagreb (Croatia)

The construction of differential algebras related to the $\kappa$-Minkowski space is discussed. We find that, requiring the differential calculus to be compatible with the $\kappa$-Poincar\’e-Hopf algebra, it is in general necessary to introduce an additional generator, which we can interpret as the exterior derivative. For the case of light-like deformations, the bicovariant differential calculus is of classical dimension. Furthermore, a classification of all bicovariant differential calculi of classical dimension is presented and the class corresponding to the special case with an undeformed exterior derivative and one-forms is considered.

-  Friday 10 November 2017, 14:00, room 114

Gianluca Calcagni (Inst. Estructura Materia, Madrid) : Detecting quantum gravity in the sky : Status of multifractional theories

We review recent advances in the general theory of multiscale spacetimes arising in quantum gravity, in particular about universal predictions on the running of the spacetime dimension and the emergence of a discrete scale invariance at microscopic scales. The experimental status of a specific class of proposals, called multifractional theories, is also reviewed.