Galaxies at $$\boldsymbol{z\gtrsim 10}$$ and New Opportunities for Testing Cosmological Models

The initial power spectrum of density perturbations, generated during the inflationary epoch, is now constrained by observations on scales of $$\lambda>5$$ 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 $$z\gtrsim 10$$ , which is now becoming accessible to observations. Our studies of numerical models of the large-scale structure with peaks in the initial spectrum have shown that spectral features on scales of $$\lambda>0.1$$ 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.