On the counting tensor model observables as U(N) and O(N) classical invariants

Autor: Joseph Ben Geloun
Přispěvatelé: Laboratoire d'Informatique de Paris-Nord (LIPN), Université Sorbonne Paris Cité (USPC)-Institut Galilée-Université Paris 13 (UP13)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2020
Předmět:
Zdroj: PoS
19th Hellenic School and Workshops on Elementary Particle Physics and Gravity
19th Hellenic School and Workshops on Elementary Particle Physics and Gravity, Aug 2019, Corfu, Greece. pp.175, ⟨10.22323/1.376.0175⟩
DOI: 10.22323/1.376.0175
Popis: Real or complex tensor model observables, the backbone of the tensor theory space, are classical (unitary, orthogonal, symplectic) Lie group invariants. These observables represent as colored graphs, and that representation gives an handle to study their combinatorial, topological and algebraic properties. We give here an overview of the symmetric group-theoretic formulation of the enumeration of unitary and orthogonal invariant observables which turns out to bear a rich structure. From their counting formulae, one finds a correspondence with topological field theory on 2-cellular complexes that brings other interpretations of the same countings. Furthermore, tensor model observables span an algebra that turns out to be semi-simple. Dealing with complex tensors, we discuss the representation theoretic base of the algebra making explicit its Wedderburn-Artin decomposition. The real case is more subtle as a base of its Wedderburn-Artin decomposition is yet unknown.
Contribution to the Corfu Summer Institute 2019, compiling 1907.04668, 1708.03524 and ,1307.6490, 25 pages, 8 figs
Databáze: OpenAIRE