A Symmetry for the Cosmological Constant

TL;DR

This paper proposes a symmetry that suppresses matter contributions to the cosmological constant, involving a ghost copy of the Standard Model, with implications for gravity, inflation, and testable deviations from General Relativity.

Contribution

It introduces a novel symmetry, Energy -> - Energy, to address the cosmological constant problem, linking ghost fields and potential Lorentz-violation at short distances.

Findings

Inflation can occur within this framework.

Flat spacetime decay via ghost production is slow due to weak Lorentz-violation.

The model predicts testable deviations from General Relativity at short distances.

Abstract

We study a symmetry, schematically Energy -> - Energy, which suppresses matter contributions to the cosmological constant. The requisite negative energy fluctuations are identified with a "ghost" copy of the Standard Model. Gravity explicitly, but weakly, violates the symmetry, and naturalness requires General Relativity to break down at short distances with testable consequences. If this breakdown is accompanied by gravitational Lorentz-violation, the decay of flat spacetime by ghost production is acceptably slow. We show that inflation works in our scenario and can lead to the initial conditions required for standard Big Bang cosmology.