Particle Content of Quadratic and $f(R_{\mu\nu\sigma \rho})$ Theories in $(A)dS$

TL;DR

This paper analyzes the particle content of quadratic and $f(R_{ ho u hetaeta})$ gravity theories around (A)dS vacua, explicitly deriving the masses of their spin-2 and spin-0 modes.

Contribution

It provides a complete decoupling of degrees of freedom and explicit mass formulas for modes in quadratic and $f(R)$ gravity theories around maximally symmetric vacua.

Findings

Explicit mass formulas for spin-2 and spin-0 modes.

Decoupling of degrees of freedom in quadratic and $f(R)$ theories.

Analysis applicable to any maximally symmetric vacuum.

Abstract

We perform a complete decoupling of the degrees of freedom of quadratic gravity and the generic $f (R_{\mu\nu\sigma \rho})$ theory about any one of their possible vacua, i.e. maximally symmetric solution, find the masses of the spin-2 and spin-0 modes in explicit forms.