Quantum fluctuations in planar domain-wall space-times: A possible origin of primordial preferred direction

Abstract

We study the gravitational effects of a planar domain wall on quantum fluctuations of a massless scalar field during inflation. By obtaining an exact solution of the scalar field equation in de Sitter space, we show that the gravitational effects of the domain wall break the rotational invariance of the primordial power spectrum without affecting the translational invariance. The strength of rotational violation is determined by one dimensionless parameter $\beta$, which is a function of two physical parameters, the domain wall surface tension $\sigma$ and cosmological constant $\Lambda$. In the limit of small $\beta$, the leading effect of rotational violation of the primordial power spectrum is scale-invariant.

5 pages, no figure; Section 2 is added; Introduction and Section 4 are modified; In v3, primordial curvature perturbation is discussed in Sec. 4; Introduction, Sec 2, and Sec 4 are modified

References in corpus (3)

• Primordial Gravitational Waves and Cosmology
• Testing a direction-dependent primordial power spectrum with observations of the Cosmic Microwave Background
• Domain wall space-times with a cosmological constant

Cited by in corpus (7)

• Inflationary power asymmetry from primordial domain walls
• Inflation and primordial power spectra at anisotropic spacetime inspired by Planck's constraints on isotropy of CMB
• Direction dependence of the power spectrum and its effect on the Cosmic Microwave Background Radiation
• Anisotropic cosmology and inflation from tilted Bianchi IX model
• Position Space CMB Anomalies from Multi-Stream Inflation
• Primordial inhomogeneities from massive defects during inflation
• Primordial anisotropies from cosmic strings during inflation