Graviton and scalar propagations on AdS(4) space in f(R) gravities

TL;DR

This paper examines how gravitons and scalar fields propagate in AdS4 space within f(R) gravity models, revealing a vDVZ discontinuity that distinguishes these models from general relativity due to an extra scalar degree of freedom.

Contribution

It demonstrates the presence of the vDVZ discontinuity in f(R) gravity on AdS4, highlighting the difference from GR caused by an additional scalar mode.

Findings

vDVZ discontinuity exists in f(R) gravity on AdS4

f(R) gravity behaves like GR with an extra scalar

Propagation characteristics differ from standard GR

Abstract

We investigate propagations of graviton and additional scalar on four-dimensional anti de Sitter (AdS$_4$) space using $f(R)$ gravity models with external sources. It is shown that there is the van Dam-Veltman-Zakharov (vDVZ) discontinuity in $f(R)$ gravity models because $f(R)$ gravity implies GR with additional scalar. This indicates a difference between general relativity and $f(R)$ gravity clearly.