Tachyonic Quintessence and a Preferred Direction in the Sky

TL;DR

This paper proposes that a tachyonic quintessence field can amplify primordial gradients, potentially creating a preferred direction in the universe observable through CMB quadrupole anomalies.

Contribution

It introduces a novel mechanism where tachyonic quintessence influences CMB anisotropies, especially at the quadrupole level, linking dark energy dynamics to cosmic anisotropy.

Findings

Primordial gradients can be amplified by tachyonic quintessence.

The mechanism primarily affects CMB quadrupole fluctuations.

Higher multipoles may also be influenced with a detailed potential analysis.

Abstract

We show that quintessence, when it is described by a tachyonic field, can amplify a tiny primordial gradient generating a preferred direction in the sky. In its simplest realization, this mechanism only affects the Cosmic Microwave Background fluctuations at the quadrupole level. We briefly discuss how higher multipoles can also be affected, once the full structure of the quintessence potential is taken into account.