Massive Gravity in de Sitter Space via Gravitational Higgs Mechanism

Understand

In this paper we discuss massive gravity in de Sitter space via gravitational Higgs mechanism, which provides a nonlinear definition thereof.

• The Higgs scalars are described by a nonlinear sigma model, which includes higher derivative terms required to obtain the Fierz-Pauli mass term.
• Using the aforesaid non-perturbative definition, we address appearance of an enhanced local symmetry and a null norm state in the linearized massive gravity in de Sitter space at the special value of the graviton mass to the Hubble parameter ratio.
• By studying full non-perturbative equations of motion, we argue that there is no enhanced symmetry in the full nonlinear theory.