On Emergent Gravity, Ungravity and $\Lambda$

TL;DR

This paper explores how 'ungravity' modifications to black hole entropy can lead to altered Friedmann equations, providing a potential origin for the cosmological constant within a modified gravity framework.

Contribution

It introduces a model linking 'ungravity' effects to the cosmological constant via thermodynamic and black hole entropy modifications.

Findings

Ungravity modifies the entropy-area relationship.

Modified Friedmann equations suggest an effective cosmological constant.

The model offers a potential 'ungravity' origin for dark energy.

Abstract

In this paper we study the "ungravity" modifications to the Friedmann equations. By using the first law of thermodynamics and the modified entropy area relationship derived from the "ungravity" contributions to the Schwarzschild black hole, we obtain modifications to the Friedmann equation that in the late time regime gives an effective cosmological constant. Therefore, this simple model can provide an "ungravity" origin to the cosmological constant $\Lambda$.