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The First Compact Objects in the $Λ$-dominated Universe

Slawomir Stachniewicz·Marek Kutschera
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Abstract

We calculate the evolution of a low-mass ($M \le 10^5 M_{\odot}$) spherically symmetric density perturbation in the $Ω_b h^2=0.02$, $Ω_M =0.35$, $Ω_Λ=0.65$, $h=0.72$ Universe. The results are compared with the ones that assume no cosmological constant and the flat, dark matter dominated Universe. We include thermal processes and non-equilibrium chemical evolution of the collapsing gas. We find that direct formation of bound objects with such masses by $z=8$ is unlikely so in fact they may form only through fragmentation of greater objects. This is in stark contrast to the $Ω=1$ pure CDM cosmology, where low-mass objects form abundantly at redshits $z>10$.

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Slawomir Stachniewicz, Marek Kutschera. 2002-12-05. The First Compact Objects in the $Λ$-dominated Universe. https://doi.org/10.1046/j.1365-8711.2003.06200.x

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