Primordial inhomogeneities from massive defects during inflation

TL;DR

This paper investigates how local massive defects during inflation, like black holes, induce specific inhomogeneities and anisotropies in the primordial power spectrum, potentially explaining observable CMB asymmetries.

Contribution

It provides a perturbative analysis of the effects of massive defects on inflationary inhomogeneities and identifies configurations leading to large observable dipole asymmetries.

Findings

Calculated amplitudes of dipole, quadrupole, and octupole anisotropies.

Identified configurations for large observable dipole asymmetry.

Discovered a reflection symmetry in defect configurations relative to the CMB sphere.

Abstract

We consider the imprints of local massive defects, such as a black hole or a massive monopole, during inflation. The massive defect breaks the background homogeneity. We consider the limit that the physical Schwarzschild radius of the defect is much smaller than the inflationary Hubble radius so a perturbative analysis is allowed. The inhomogeneities induced in scalar and gravitational wave power spectrum are calculated. We obtain the amplitudes of dipole, quadrupole and octupole anisotropies in curvature perturbation power spectrum and identify the relative configuration of the defect to CMB sphere in which large observable dipole asymmetry can be generated. We observe a curious reflection symmetry in which the configuration where the defect is inside the CMB comoving sphere has the same inhomogeneous variance as its mirror configuration where the defect is outside the CMB sphere.