Year: 2026
Type: article
Abstract: It is well-established that the Minkowski limit of pure $f(R)=R^2$ gravity breaks down, unlike that of full Starobinsky theory $f(R)=R+αR^2$. We provide a novel interpretation of this phenomenon using the recent thermal analogy between scalar-tensor gravity and Eckart's relativistic dissipative fluids. In this framework, we show that approaching the Minkowski background corresponds to a diverging effective ``gravitational temperature''. This perspective naturally rephrases the strong coupling problem as a thermal singularity, demonstrating that $R^2$ gravity departs infinitely far from General Relativity rather than recovering it.
DOI: 10.1103/yhxk-dd5w
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7166514940