https://doi.org/10.1140/epjc/s10052-017-4927-1
Regular Article - Theoretical Physics
Remarks on a gauge theory for continuous spin particles
Instituto de Física, Universidade de São Paulo, Rua do Matão, 1371, São Paulo, SP, 05508-090, Brazil
* e-mail: rivelles@fma.if.usp.br
Received:
4
November
2016
Accepted:
17
May
2017
Published online:
29
June
2017
We discuss in a systematic way the gauge theory for a continuous spin particle proposed by Schuster and Toro. We show that it is naturally formulated in a cotangent bundle over Minkowski spacetime where the gauge field depends on the spacetime coordinate and on a covector
. We discuss how fields can be expanded in
in different ways and how these expansions are related to each other. The field equation has a derivative of a Dirac delta function with support on the
-hyperboloid
and we show how it restricts the dynamics of the gauge field to the
-hyperboloid and its first neighbourhood. We then show that on-shell the field carries one single irreducible unitary representation of the Poincaré group for a continuous spin particle. We also show how the field can be used to build a set of covariant equations found by Wigner describing the wave function of one-particle states for a continuous spin particle. Finally we show that it is not possible to couple minimally a continuous spin particle to a background abelian gauge field, and we make some comments about the coupling to gravity.
© The Author(s), 2017