The Redshift Evolution of LCDM Halo Parameters

TL;DR

This paper investigates how the concentration parameter of LCDM dark matter haloes evolves with mass and redshift using N-body simulations, providing new fitting formulas and physical insights into halo formation.

Contribution

It introduces accurate fitting formulas for the concentration-mass relation evolution and offers a physical model based on spherical collapse to explain observed trends.

Findings

Fitting formulas accurately describe concentration evolution from z=2 to present.

Physical insights into the origin of concentration evolution during halo assembly.

Preliminary model predictions align with simulation data.

Abstract

We study the mass and redshift dependence of the concentration parameter in Nbody simulations spanning masses from $10^{10} \hMsun$ to $10^{15} \hMsun$ and redshifts from 0 to 2. We present a series of fitting formulas that accurately describe the time evolution of the concentration-mass relation since z=2. Using arguments based on the spherical collapse model we study the behaviour of the scale length of the density profile during the assembly history of haloes, obtaining physical insights on the origin of the observed time evolution of the concentration mass relation. We present preliminary results of the implementation of this model in the prediction of the values of the concentration parameter for different masses and redshifts.