Séminaire de Physique Théorique
(Non-)unitarity of massless higher spin fermions in de Sitter spaceVasileios Letsios (King's College London, UK)
Thursday 29 February 2024 14:00 - Salle des séminaires - Salle 1180, bâtiment E2
Résumé :
As in Minkowskian QFT, for each unitary free field theory in D-dimensional de Sitter (dS) space, one can construct a `dictionary’ between the corresponding one-particle Hilbert space and a Unitary Irreducible Representation of the dS algebra, so(D,1). Such a dictionary for bosonic fields of any spin has been constructed by Higuchi, as well as by Basile, Bekaert, and Boulanger. However, the dictionary for fermionic higher-spin fields is absent from the literature. In this talk, we will make a first attempt to fill this gap in the case of the spin-3/2 field. Remarkably, we find that 4-dimensional dS space plays a distinguished role in the unitarity of the massless spin-3/2 field (i.e. gravitino). In particular, this field theory cannot be unitary unless D=4. This talk is based on https://doi.org/10.1007/JHEP05(2023)015.
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