Gravitational Collapse of Dark Energy Field Configurations

On the spherical collapse model in dark energy cosmologies

We study the spherical collapse model in dark energy cosmologies, in which dark energy is modelled as a minimally coupled scalar field. We first follow the standard assumption that dark energy does not cluster on the scales of interest. Investigating four different popular potentials in detail, we show that the predictions of the spherical collapse model depend on the potential used. We also investigate the dependence on the initial conditions. Secondly, we investigate in how far perturbations in the quintessence field affect the predictions of the spherical collapse model. In doing so, we ass…

Galactic Collapse of Scalar Field Dark Matter

We present a scenario for galaxy formation based on the hypothesis of scalar field dark matter. We interpret galaxy formation through the collapse of a scalar field fluctuation. We find that a cosh potential for the self-interaction of the scalar field provides a reasonable scenario for galactic formation, which is in agreement with cosmological observations and phenomenological studies in galaxies.

非最小引力暗物质晕中孤子的新结构与坍缩

Novel structures and collapse of solitons in nonminimally gravitating dark matter halos

本文通过模拟研究非最小引力效应下暗物质孤子的形成与坍缩，发现负势曲率区域的出现以及正负耦合常数下孤子均在临界密度坍缩，并验证了强非最小引力效应可促进多尺度结构形成。

Gravitinos from Gravitational Collapse

We reanalyse the limits on the gravitino mass $m_{3/2}$ in superlight gravitino scenarios derived from arguments on energy-loss during gravitational collapse. We conclude that the mass range $10^{-6}eV\leq m_{3/2}\leq2.3\times10^{-5}eV$ is excluded by SN1987A data. In terms of the scale of supersymmetry breaking $Λ$, the range $70GeV\leqΛ\leq 300GeV$ is not allowed.

Constraints on Light Dark Matter From Core-Collapse Supernovae

We show that light ($\simeq$ 1 -- 30 MeV) dark matter particles can play a significant role in core-collapse supernovae, if they have relatively large annihilation and scattering cross sections, as compared to neutrinos. We find that if such particles are lighter than $\simeq$ 10 MeV and reproduce the observed dark matter relic density, supernovae would cool on a much longer time scale and would emit neutrinos with significantly smaller energies than in the standard scenario, in disagreement with observations. This constraint may be avoided, however, in certain situations for which the neutrin…

Reply to astro-ph/9612003 ("Comments on 'Biological Effects of Stellar Collapse Neutrinos'") and astro-ph/9612214 ("Volcanogenic Dark Matter and Mass Extinctions")

A Reply to the criticisms contained in astro-ph/9612003 is provided and a logical inconsistency in astro-ph/9612214 is pointed out.