TY  - GEN
N2  - The amplitude and shape of the density fluctuation power spectrum today are determined by the initial conditions set after inflation, the properties of dark matter particles and the growth of structures due to the gravitational interaction in an expanding spacetime. Since cosmic structure formation is highly non-linear, the impact of the properties of dark matter on today?s structure or results from N-body simulations like the observed universal halo density profiles, are hard to understand with conventional analytical methods. While these approaches break down at small scales when particle streams cross, Kinetic Field Theory (KFT) operates with a generating functional in classical N-particle phase space, circumventing those problems. In this work, we present novel asymptotic methods that apply to rapidly oscillating integrals with two large parameters. Applying these methods to KFT, we derive the asymptotic limit of the power spectrum on small scales in the Zel?dovich approximation.  The  power  spectrum  universally  develops  a k^?3 tail,  independent  of  the steepness of the initial spectrum, suggesting that scale-invariant structures form below a characteristic length scale already early in cosmic history. Finally, we derive the asymptotics of the factors of the factorized generating functional to guide their numerical implementation. These factors are indispensable for the numerical evaluation of perturbation theory and density correlation functions of high order within the framework of KFT.
A1  - Konrad, Sara
AV  - public
Y1  - 2020///
ID  - heidok29253
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/29253/
CY  - Heidelberg
TI  - Cosmic Structure Formation in the Limit of Small Scales within Kinetic Field Theory
ER  -