Accelerated cosmological expansion from pseudo-Hermiticity

TL;DR

This paper demonstrates that pseudo-Hermitian field theories with complex scalar fields can induce accelerated cosmic expansion through a novel mechanism involving broken antilinear symmetry and complex eigenspectra.

Contribution

It introduces a new mechanism for cosmic acceleration based on pseudo-Hermitian field theories, highlighting dynamics unique to broken antilinear symmetry regimes.

Findings

Pseudo-Hermitian fields can produce self-sustaining accelerated expansion.

Late-time behavior involves azimuthal fields with constant rolling rates.

The mechanism operates even with zero classical vacuum energy.

Abstract

We show that a well-studied pseudo-Hermitian field theory composed of two complex scalar fields can generate accelerated cosmological expansion through a novel mechanism. The dynamics is unique to the pseudo-Hermitian field theory, and it arises in the regime of broken antilinear symmetry, wherein a growth instability from the resulting complex eigenspectrum competes with the Hubble damping. The azimuthal components of the complex scalar fields asymptote to a constant rate of rolling at late times, reminiscent of motion around the infinite staircase of M.C. Escher's lithograph "Ascending and Descending". The resulting centripetal acceleration drives the radial components of the field away from the minimum of the potential, and the system generates a self-sustaining and constant Hubble rate at late times, even when tuning the minimum of the potential such that the classical vacuum energy is vanishing. This result evidences the potential to generate novel and physically relevant dynamics that are unique to pseudo-Hermitian field theories, and that their regimes of broken antilinear symmetry can be physically relevant in dynamical spacetimes.