On multi-graviton and multi-gravitino gauge theories

TL;DR

This paper explores nonlinear gauge theories involving multiple spin-2 and spin-3/2 fields, revealing new algebraic structures and extending gravity theories with novel anticommutative, anti-associative algebra frameworks.

Contribution

It introduces a systematic method to classify all possible nonlinear deformations of multi-spin gauge theories using algebra-valued fields and uncovers new gauge theories based on anti-commutative, anti-associative algebras.

Findings

All deformations of spin-2 fields correspond to algebra-valued Einstein gravity.

Discovery of a new nonlinear gauge theory with anticommutative, anti-associative algebra structure.

Supersymmetric extensions incorporating spin-3/2 fields are achieved.

Abstract

This paper studies nonlinear deformations of the linear gauge theory of any number of spin-2 and spin-3/2 fields with general formal multiplication rules in place of standard Grassmann rules for manipulating the fields, in four spacetime dimensions. General possibilities for multiplication rules and coupling constants are simultaneously accommodated by regarding the set of fields equivalently as a single algebra-valued spin-2 field and single algebra-valued spin-3/2 field, where the underlying algebra is factorized into a field-coupling part and an internal multiplication part. The condition that there exist a gauge invariant Lagrangian (to within a divergence) for these algebra-valued fields is used to derive determining equations whose solutions give all allowed deformation terms, yielding nonlinear field equations and nonabelian gauge symmetries, together with all allowed formal multiplication rules as needed in the Lagrangian for demonstration of invariance under the gauge symmetries and for derivation of the field equations. In the case of spin-2 fields alone, the main result of this analysis is that all deformations (without any higher derivatives than appear in the linear theory) are equivalent to an algebra-valued Einstein gravity theory. By a systematic examination of factorizations of the algebra, a novel type of nonlinear gauge theory of two or more spin-2 fields is found, where the coupling for the fields is based on structure constants of an anticommutative, anti-associative algebra, and with formal multiplication rules that make the fields anticommuting (while products obey anti-associativity). Supersymmetric extensions of these results are obtained in the more general case when spin-3/2 fields are included.