Flowing in discrete gravity models and Ward identities: a review
Résumé
Ward–Takahashi identities are nonperturbative relations between correlation functions and arising from symmetries in quantum and statistical fields theories, as Noether currents conservation for classical theories. Since their historical origin, these identities were considered to prove the exact relation between counter-terms to all order of the perturbative expansion. Recently they have been considered in relation with nonperturbative renormalization group aspects for some classes of quantum field theories namely tensorial group field theories and matrix models, both characterized by a specific non-locality in their interactions, and expected to provide discrete models for quantum gravity. In this review, we summarize the state of the art, focusing on the conceptual aspects rather than technical subtleties, and provide a unified reflection on this novel and promising way of investigation. We attached great importance to the pedagogy and the self-consistency of the presentation.
Mots clés
Tensorial group field theories
Matrix models
large-N limit
Ward-Takahashi identities
renormalization group
quantum gravity
model: discrete
renormalization group: nonperturbative
field theory: statistical
gravitation: discrete
field theory: group
gravitation: model
Ward-Takahashi identity
field theory
conservation law
Ward identity
matrix model
reflection
Noether