Dark Energy Driven by the Cohen-Kaplan-Nelson Bound

TL;DR

This paper explores how a quantum field theory bound relating UV and IR cutoffs can explain the observed time-varying dark energy in the universe, aligning theoretical bounds with recent cosmological data.

Contribution

It connects the Cohen-Kaplan-Nelson bound with dark energy observations, proposing a dynamic vacuum energy model consistent with DESI data.

Findings

Time-varying dark energy models are preferred over $b1$CDM by recent data.

The UV-IR bound predicts a vacuum energy contribution evolving with the Hubble horizon.

The model aligns theoretical quantum bounds with observational cosmology.

Abstract

In this work, we confront the bound on an ultraviolet cutoff (UV) of a quantum field theory (QFT) proposed by Cohen, Kaplan, and Nelson (CKN) with the latest results of the Dark Energy Spectroscopic Instrument (DESI). The former relates the UV cutoff with an infrared (IR) cutoff of the theory by excluding all states describing a black hole. Identifying now the IR cutoff with the Hubble horizon yields a time-varying contribution of the vacuum energy to the dark energy density of the universe. At the same time the DESI results in combination with other cosmological data point towards a preference of time-varying dark energy models over $\Lambda$CDM.