Hydrogen Burning in Low Mass Stars Constrains Alternative Gravity Theories

TL;DR

This paper investigates how alternative scalar-tensor gravity theories affect the minimum mass for hydrogen burning in stars, using observations of low-mass stars to constrain these theories and related dark energy parameters.

Contribution

It calculates the hydrogen burning mass limit under various scalar-tensor gravity theories and uses stellar observations to rule out many such theories.

Findings

Minimum hydrogen burning mass is larger in alternative theories than in general relativity.

Observations of low-mass stars exclude a broad class of scalar-tensor gravity models.

Constraints are placed on cosmological parameters related to dark energy.

Abstract

The most general scalar-tensor theories of gravity predict a weakening of the gravitational force inside astrophysical bodies. There is a minimum mass for hydrogen burning in stars that is set by the interplay of plasma physics and the theory of gravity. We calculate this for alternative theories of gravity, and find that it is always significantly larger than the general relativity prediction. The observation of several low mass Red Dwarf stars therefore rules out a large class of scalar-tensor gravity theories, and places strong constraints on the cosmological parameters appearing in the effective field theory of dark energy.