Some remarks on axion dark matter, dark energy and energy of the quantum vacuum

TL;DR

This paper discusses constraints on axion interactions from Casimir force experiments and examines the quantum vacuum's role in dark energy, arguing that only the renormalized cosmological constant is physically meaningful.

Contribution

It provides new constraints on axion-nucleon interactions from Casimir force measurements and offers a critical perspective on the quantum vacuum's contribution to dark energy.

Findings

Casimir experiments yield strong constraints on axion parameters

Renormalized cosmological constant aligns with observed dark energy density

Critique of vacuum catastrophe statements in literature

Abstract

In connection with the problem of dark matter, we discuss recent results on constraining the parameters of axion-to-nucleon interaction following from the experiment on measuring the difference of Casimir forces. It is shown that this experiment not only leads to competitive constraints, but provides stronger support to other constraints obtained in Casimir physics so far. The description of dark energy by means of cosmological constant originated from the quantum vacuum is considered in terms of the renormalization procedures in quantum field theory. It is argued that only the renormalized value of cosmological constant directly connected with the observed density of dark energy is of physical significance, so that some statements in the literature concerning the vacuum catastrophe may be considered as an exaggeration.