The cosmological constant as a manifestation of the conformal anomaly?

TL;DR

This paper explores the idea that the cosmological constant may originate from the conformal anomaly in the infrared sector of gravity, proposing a new effective field theory approach with auxiliary fields to explain the observed vacuum energy.

Contribution

It introduces a novel effective field theory framework incorporating auxiliary fields to connect the conformal anomaly with the cosmological constant problem.

Findings

Proposes a low energy gravity model with IR boundary conditions.

Defines a normalization point where the cosmological constant is zero.

Predicts vacuum energy evolution based on IR parameters.

Abstract

We propose that the solution to the cosmological vacuum energy puzzle may come from the infrared sector of the effective theory of gravity, where the impact of the trace anomaly is of upmost relevance. We proceed by introducing two auxiliary fields, which are capable of describing a diversity of quantum states via specification of their macroscopic (IR) boundary conditions, in contrast to ultraviolet quantum effects. Our investigation aims at finding a realistic cosmological solution which interprets the observed cosmological constant as a well defined deficit in the zero point energy density of the Universe. The energy density arises from a phase transition, which alters the properties of the quantum ground state. We explicitly formulate low energy gravity as an effective field theory with a precise definition of the "point of normalization" as the point at which the "renormalized cosmological constant" is set to zero in the Minkowski vacuum, in which the Einstein equations are automatically satisfied as the Ricci tensor identically vanishes. With this definition the effective QFT of gravity has a predictive power. In particular, it must predict the evolution of the system in any nontrivial geometry, including the vacuum energy behaviour as a function of infrared, rather than ultraviolet, input parameters.