Excess of high-$z$ galaxies as a test for bumpy power spectrum of density perturbations

Understand

Modified matter power spectra with approximately Gaussian bump on sub-Mpc scales can be a result of a complex inflation.

• We consider five spectra with different Gaussian amplitudes $A$ and locations $k_0$ and run N-body simulations in a cube $(5 Mpc/h)^3$ at $z>8$ to reveal the halo mass functions and their evolution with redshift.
• We have found that the Sheth-Tormen formula provides a good approximation to a such kind of halo mass functions.
• In the considered models the dark matter halo formation starts much more earlier than in $\Lambda$CDM, which in turn can result in an earlier star formation and a nuclear activity in galaxies and can be detected and tested by, e.g., JWST.