O(4) texture with a cosmological constant

TL;DR

This paper studies O(4) textures in a universe with a positive cosmological constant, finding static solutions, their stability, and the behavior of scalar fields near horizons in an expanding background.

Contribution

It introduces new static solutions for O(4) textures in a cosmological setting with a positive cosmological constant, analyzing their properties and stability.

Findings

Existence of static solutions co-moving with the expanding universe.

Identification of solutions with regular and singular scalar fields at the horizon.

Critical winding number determines stability of the solutions.

Abstract

We investigate O(4) textures in a background with a positive cosmological constant. We find static solutions which co-move with the expanding background. There exists a solution in which the scalar field is regular at the horizon. This solution has a noninteger winding number smaller than one. There also exist solutions in which scalar-field derivatives are singular at the horizon. Such solutions can complete one winding within the horizon. If the winding number is larger than some critical value, static solutions including the regular one are unstable under perturbations.