The cosmological constant from space-time discreteness

TL;DR

This paper models space-time as discrete at the Planck scale, proposing a thermodynamic approach that links particle energy limits to the universe's expansion, providing a novel explanation for dark energy and the cosmological constant.

Contribution

It introduces a discrete space-time model with a temperature-dependent energy limit, deriving a modified conservation law that explains the observed cosmological constant.

Findings

Effective cosmological constant consistent with observations

Modified conservation equation for universe's energy

Particles released during expansion contribute to dark energy

Abstract

We regard the background of space-time as a physical system composed of discrete volume elements at the Planck scale and get the internal energy of space-time by Debye model. A temperature-dependent minimum energy limit of the particles is proposed from the thermal motion part of the internal energy. As decreases of the temperature caused by the expansion of the universe, more and more particles would be"released" because of the change of the energy limit, we regard these new particles as a source of dark energy. The minimum energy limit also leads to a corrected number of particles in universe and a modified conservation equation. According to the modified conservation equation, an effective cosmological constant consistent with its observed value is obtained.