arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2008.10264astro-ph.CO
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弹跳宇宙中的冷与热暗物质

Warm and Cold Dark Matter in Bouncing Universe

Changhong Li

摘要:

由于摆脱了初始奇点,弹跳宇宙学成为暴胀的一个有希望的替代方案。然而,在后反弹阶段的熵产生仍然不清楚。在这项工作中,我们使用一个新推出的DM候选人(EQFIDM),它可以直接冻结在热平衡反弹后不久,跟踪剩余弹跳场(RBF)的熵产生衰减过程。具体来说,我们提出了一个模型独立的形式主义,以获得所有九种可能类型的熵产生衰变的RBF在一个通用的弹跳宇宙,并表明,由于在不同类型的熵生产,这个新的候选人的粒子质量可以从sub-keV规模到super-TeV规模。利用Lyman- $α$森林模型对线性物质谱的观测,我们发现,虽然有四种类型被排除在外,但其余五种类型(它们表明具有有效熵产生的冷暖EQFIDM候选者)与当前观测相适应。然后,我们说明了如何RBF的性质可以约束当前的观察和EQFIDM缓解小规模危机的潜力。

英文摘要:

Being free from the initial singularity, bouncing cosmology serves as a promising alternative to inflation. However, the entropy production during the post-bounce phase is still unclear. In this work, we use a newly unveiled DM candidate (EQFIDM), which can directly freeze in thermal equilibrium shortly after bounce, to trace the entropy-producing decay process of residual bouncing field (RBF). Specifically, we present a model-independent formalism to obtain all nine possible types of the entropy-producing decay of RBF within a generic bouncing universe, and show that, due to the entropy productions in different types, the particle mass of this new candidate can range from sub-keV scale to super-TeV scale. With current Lyman-$α$ forest observation on linear matter spectrum, we find that, although four types have been excluded, the rest five types, which suggest warm and cold EQFIDM candidates with effective entropy productions, are accommodated with current observation. Then we illustrate how the nature of RBF can be constrained by current observation and investigate the potential of EQFIDM on alleviating small-scale crisis.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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