Observations of Galaxies at $z\gtrsim10$ Allow to Test Cosmological Models with Features in the Initial Power Spectrum

TL;DR

This paper explores how observing galaxies at high redshifts ($z oughly10$) can test cosmological models that include features like peaks in the initial power spectrum of density perturbations, which are linked to inflationary processes.

Contribution

It proposes methods to detect non-power-law features in the initial power spectrum on small scales and demonstrates how these features influence galaxy clustering and properties at high redshifts.

Findings

Spectral features on scales >0.1 Mpc affect galaxy clustering.

Peaks in the initial spectrum influence galaxy mass functions and sizes.

Observations at $z oughly10$ can constrain models with spectral peaks.

Abstract

The initial power spectrum of density perturbations, generated during the inflationary epoch, is now constrained by observations on scales $\lambda>5$~Mpc and has a power-law form. The peculiarities of the inflationary process can lead to the appearance of non-power-law contributions to this spectrum, such as peaks. The exact size and shape of the peak cannot be predicted in advance. In this paper, we propose methods for searching for such peaks in the region of the spectrum with $\lambda<5$~Mpc. Perturbations on these scales enter the nonlinear stage at $z\gtrsim10$, which is now becoming accessible to observations. Our studies of numerical models of large-scale structure with peaks in the initial spectrum have shown that spectral features on scales with $\lambda>0.1$~Mpc manifest in the clustering of galaxies, as well as affect their mass function, sizes, and density. Studying these characteristics of distant galaxies will allow us to constrain cosmological models with peaks.