Interactions for Partially-Massless Spin-2 Fields
- PDF / 302,903 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 77 Downloads / 193 Views
HYSICS OF ELEMENTARY PARTICLES AND ATOMIC NUCLEI. THEORY
Interactions for Partially-Massless Spin-2 Fields N. Boulangera, *, S. Garcia-Saenzb, **, and L. Trainaa, *** a
Physics of the Universe, Fields and Gravitation, Department of Physics, Science Faculty, University of Mons—UMONS, Mons, B-7000 Belgium b Theoretical Physics, Blackett Laboratory, Imperial College, London, SW7 2AZ, U.K. *e-mail: [email protected] **e-mail: [email protected] ***e-mail: [email protected] Received November 15, 2019; revised January 15, 2020; accepted February 28, 2020
Abstract—We review the theory for a multiplet of interacting partially massless spin-2 fields around (anti-) de Sitter (A)dS D background and give new results concerning the couplings between a massless spin-1 vector field and a partially massless spin-2 field. DOI: 10.1134/S1547477120050064
INTRODUCTION Partially massless (PM) fields of spin-2 have been subject to renewed attention in recent years after the important advances made in the understanding of massive gravity [1, 2]. In four-dimensional de Sitter (dS4 ) spacetime with (positive) cosmological constant 2 Λ , a PM graviton has a mass given by mPM = 2Λ /3 and a corresponding gauge invariance that removes the degree of freedom associated with the spin-zero mode of the particle. A consistent theory of PM gravity would be very attractive given its relevance in the context of cosmology and the fact that a PM spin-2 field is not subject to the same strict experimental constraints as a generic massive graviton, e.g. the bounds on fifth-force experiments or on dispersion of gravitational waves. In spite of their potentially interesting phenomenology, complete and physically realistic models involving PM fields are currently lacking. A crucial hurdle one encounters when attempting to construct such a PM theory beyond linear level is the requirement of gauge invariance of the interactions. Indeed, this condition is restrictive enough to rule out theories of a single self-interacting PM spin-2 particle, see e.g. [3–5]. Such no-go results beg the question of whether a fundamental obstruction exists for the construction of non-trivial PM models. A first step in order to address this question is to precisely understand what are the assumptions that lead to the existing negative results. In the recent work [6] we have shown that, by relaxing the requirement of classical unitarity, one can in fact construct a complete theory for a multiplet of PM gravitons around (A)dS4 space, as we review in the following. This is an interesting outcome as it demon-
strates that gauge invariance itself is not a fundamental obstacle for the existence of a nontrivial interacting PM spin-2 theory. In addition, motivated by the field content of a putative supersymmetric theory of PM gravity (as identified in [7]), we present some new results on the interactions between a massless spin-1 field and a PM spin-2 field. 1. SET-UP We will look for consistent deformations of the theory consisting of an arbitrary number of
Data Loading...
