Cosmological constant as a finite temperature effect

TL;DR

This paper explores a finite temperature approach to the cosmological constant problem, proposing a renormalization scheme that avoids fine-tuning by linking the Higgs mass to the CMB temperature, and discusses implications for new physics.

Contribution

It introduces a novel renormalization scheme at finite temperature that potentially resolves the cosmological constant fine-tuning issue without altering physical values.

Findings

Renormalized Higgs mass can be set to the order of the CMB temperature.

Finite-temperature effects induce complexification of the effective potential.

The approach suggests a shift of the problem to new physics in the perturbation series.

Abstract

We reexamine the cosmological constant problem in a finite temperature setup and propose an intriguing possibility of carrying out perturbative analysis by employing a renormalization scheme in which the renormalized Higgs mass (or resummed mass, to be more precise) is taken to be on the order of the CMB temperature. Our proposal hinges on the fact that although the physical value of the cosmological constant does not depend on one's renormalization scheme, whether or not a fine tuning is involved does. The cosmological constant problem is avoided in the sense that the renormalization process no longer requires finetuning. This is achieved essentially by renormalization scheme-independence of a physical quantity, which in turn is assured by bare perturbation theory. The proposal shifts the cosmological constant problem to a peculiarity of the consequent perturbation series for the Higgs mass (and other massive sectors of the Standard Model); the peculiarity is interpreted as an indicator of new physics after the expected mathematical structure of the series is scrutinized. Finite-temperature-induced complexification of the effective potential is observed and its interpretation is given. A consistency check in the cosmology context is suggested.