792 research outputs found
The continuous spin limit of higher spin field equations
We show that the Wigner equations describing the continuous spin
representations can be obtained as a limit of massive higher-spin field
equations. The limit involves a suitable scaling of the wave function, the mass
going to zero and the spin to infinity with their product being fixed. The
result allows to transform the Wigner equations to a gauge invariant
Fronsdal-like form. We also give the generalisation of the Wigner equations to
higher dimensions with fields belonging to arbitrary representations of the
massless little group.Comment: 18 pages, JHEP style. Typos corrected, references adde
How higher-spin gravity surpasses the spin two barrier: no-go theorems versus yes-go examples
Aiming at non-experts, we explain the key mechanisms of higher-spin
extensions of ordinary gravity. We first overview various no-go theorems for
low-energy scattering of massless particles in flat spacetime. In doing so we
dress a dictionary between the S-matrix and the Lagrangian approaches,
exhibiting their relative advantages and weaknesses, after which we high-light
potential loop-holes for non-trivial massless dynamics. We then review positive
yes-go results for non-abelian cubic higher-derivative vertices in constantly
curved backgrounds. Finally we outline how higher-spin symmetry can be
reconciled with the equivalence principle in the presence of a cosmological
constant leading to the Fradkin--Vasiliev vertices and Vasiliev's higher-spin
gravity with its double perturbative expansion (in terms of numbers of fields
and derivatives).Comment: LaTeX, 50 pages, minor changes, many refs added; version accepted for
publication in Reviews of Modern Physic
A gauge field theory of fermionic Continuous-Spin Particles
In this letter, we suggest a local covariant action for a gauge field theory
of fermionic Continuous-Spin Particles (CSPs). The action is invariant under
gauge transformations without any constraint on both the gauge field and the
gauge transformation parameter. The Fang-Fronsdal equations for a tower of
massless fields with all half-integer spins arise as a particular limit of the
equation of motion of fermionic CSPs.Comment: 8 pages, no figure. Due to the constructive contribution of X.
Bekaert in this letter, his name is added as a new author. This version of
the paper accepted for publication in PLB(2016
Tensor gauge fields in arbitrary representations of GL(D,R): II. Quadratic actions
Quadratic, second-order, non-local actions for tensor gauge fields
transforming in arbitrary irreducible representations of the general linear
group in D-dimensional Minkowski space are explicitly written in a compact form
by making use of Levi-Civita tensors. The field equations derived from these
actions ensure the propagation of the correct massless physical degrees of
freedom and are shown to be equivalent to non-Lagrangian local field equations
proposed previously. Moreover, these actions allow a frame-like reformulation a
la MacDowell-Mansouri, without any trace constraint in the tangent indices.Comment: LaTeX, 53 pages, no figure. Accepted for publication in
Communications in Mathematical Physics. Local Fierz-Pauli programme achieved
by completing the analysis of Labastid
Current Exchanges for Reducible Higher Spin Multiplets and Gauge Fixing
We compute the current exchanges between triplets of higher spin fields which
describe reducible representations of the Poincare group. Through this
computation we can extract the propagator of the reducible higher spin fields
which compose the triplet. We show how to decompose the triplet fields into
irreducible HS fields which obey Fronsdal equations, and how to compute the
current-current interaction for the cubic couplings which appear in
ArXiv:0708.1399 [hep-th] using the decomposition into irreducible modes. We
compare this result with the same computation using a gauge fixed (Feynman)
version of the triplet Lagrangian which allows us to write very simple HS
propagators for the triplet fields.Comment: 26 pages, 1 table; v3 some clarifications and references added, typos
corrected. Published versio
Bosonic Massless Higher Spin Fields from Matrix Model
We study matrix models as a new approach to formulate massless higher spin
gauge field theory. As a first step in this direction, we show that the free
equation of motion of bosonic massless higher spin gauge fields can be derived
from that of a matrix model.Comment: 19pages, no figures, one reference adde
Higher-order singletons and partially massless fields
Based on the talk given by X.B. at the international conference âMathematics Days in Sofiaâ held in July 2014 at Sofia (Bulgaria)We review the following higher-spin holographic duality conjecture: the O(N) model at an isotropic Lifshitz point of criticality order l+1 should be dual to a higher-spin gravity theory whose spectrum contains a tower of partially massless symmetric tensor fields of all even spins and all odd depths between 1 and 2lâ1. More precisely, the Gaussian fixed point corresponding to free higher-order singletons on the d-dimensional boundary should be de-scribed in the bulk by the Vasiliev equations based on the symmetry algebra of the polywave equation of order 2l. Moreover, an elementary renormalization group analysis suggests that for l=2 and 5<d<11 both the free and the interacting isotropic Lifshitz point should be described by the same bulk theory but with distinct boundary conditions
Massless spin-two field S-duality
We present a review of the homological algebra tools involved in the standard de Rham theory and their subsequent generalizations relevant for the understanding of free massless higher spin gauge structure. M-theory arguments suggest the existence of an extension of (Abelian) S-duality symmetry for non-Abelian gauge theories, like the four dimensional Yang-Mills or Einstein theories. Some no-go theorems prove that this extension, if it exists, should fall outside the scope of local perturbative field theory
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