Negative Newton constant may destroy some conjectures

TL;DR

The paper explores how negative or zero gravitational coupling constants challenge existing gravity conjectures, testing their universality and implications for alternative universe models.

Contribution

It demonstrates that certain gravity conjectures fail in universes with non-positive gravitational coupling, questioning their universal validity.

Findings

Some gravity conjectures do not hold with zero or negative 1/G.

Negative 1/G universes challenge the universality of gravity theories.

The extension to 1/G ≤ 0 tests the robustness of gravity conjectures.

Abstract

The magnitude and sign of the gravitational coupling $1/G$ depend on the relations between different contributions from scalar, fermionic and vector fields. In principle, this may give the zero and negative values of $1/G$ in some hypothetical Universes with the proper relations between the fermionic and bosonic species. We consider different conjectures related to gravity, such as the wave function collapse caused by gravity, entropic gravity, and maximum force. We find that some of them do not work in the Universes with zero or negative $1/G$, and thus cannot be considered as universal. Thus the extension of the gravitational coupling to $1/G \leq 0$ provides the test on the universality of the proposed theories of gravity.