Quantum vacuum effects as generalized f(R) gravity. Application to stars

TL;DR

This paper models quantum vacuum effects as a generalized f(R) gravity theory, adding curvature-squared terms to Einstein's action, and explores their implications for stellar stability and observational constraints.

Contribution

It introduces a modified gravity framework incorporating quantum vacuum effects via f(R) terms and analyzes their impact on stellar stability and observational bounds.

Findings

Vacuum effects imply length scales of a few millimeters to hundreds of meters.

Quantum vacuum contributions increase white dwarf stability.

Compatibility with solar system tests constrains the model parameters.

Abstract

It is assumed that, for weak spacetime curvature, the main gravitational effect of the quantum vacuum stress-energy corresponds to adding two terms to the Einstein-Hilbert action, proportional to the square of the curvature scalar and to the contraction of two Ricci tensors, respectively. It is shown that compatibility with terrestrial and solar systems observaction implies that the square roorts of the coefficients of these terms should be either a few millimeters or a few hundred meters. It is shown that the vacuum contribution increase the stability of white dwarfs.