Comment on "Existence of Einstein static universes and their stability in fourth-order theories of gravity"

TL;DR

This paper discusses the solution space of $f(R)$ gravity theories that admit Einstein static universes, emphasizing the importance of including algebraic roots to broaden the class of solutions.

Contribution

It highlights the need to expand the solution space of $f(R)$ theories by incorporating algebraic roots, challenging previous narrower approaches.

Findings

Including algebraic roots broadens the class of $f(R)$ theories admitting Einstein static universes.

The solution space for Einstein static universes in $f(R)$ gravity is more extensive than previously thought.

Algebraic roots play a crucial role in the existence of Einstein static solutions in fourth-order gravity theories.

Abstract

It is argued that the solution space of the equation determining the class of $f(R)$ theories which admit an Einstein static universe should be broadened by including the algebraic roots.