相关论文: Chilly Dark Sectors and Asymmetric Reheating

In dark matter (DM) cosmology, the central question is how the present-day density of DM is generated from some initial conditions in the early universe. Different production mechanisms of DM are instrumental in probing DM microphysics in…

The origin of dark matter as a thermal relic offers a compelling way in which the early universe was initially populated by dark matter. Alternative explanations typically appear exotic compared to the simplicity of thermal production.…

We demonstrate how a dark sector can provide a crucial link between a vacuum-dominated early universe and the later radiation-dominated epoch. As an example, we consider a feeble axion-like coupling of dark non-Abelian gauge fields with a…

Large classes of dark sector models feature mass scales and couplings very different from the ones we observe in the Standard Model (SM). Moreover, in the freeze-in mechanism, often employed by the dark sector models, it is also required…

We study models in which the inflaton is coupled to two otherwise decoupled sectors, and the effect of preheating and related processes on their energy densities during the evolution of the universe. Over most of parameter space, preheating…

The early universe could feature multiple reheating events, leading to jumps in the visible sector entropy density that dilute both particle asymmetries and the number density of frozen-out states. In fact, late time entropy jumps are…

We describe the evolution of Dark Matter (DM) abundance from the very onset of its creation from inflaton decay under the assumption of an instantaneous reheating. Based on the initial conditions such as the inflaton mass and its decay…

If the interaction rates between the visible and the dark sectors were never strong enough, the observed dark matter relic abundance could have been produced in the early Universe by non-thermal processes. This is what occurs in the…

We present a systematic cosmological study of a universe in which the visible sector is coupled, albeit very weakly, to a hidden sector comprised of its own set of particles and interactions. Assuming that dark matter (DM) resides in the…

It has recently been shown that a subdominant hidden sector of atomic dark matter in the early universe provides a novel avenue towards resolving the Hubble ($H_0$) tension while maintaining good agreement with Cosmic Microwave Background…

It has recently been shown that if the dark matter is in thermal equilibrium with a sector that is highly decoupled from the Standard Model, it can freeze-out with an acceptable relic abundance, even if the dark matter is as heavy as ~1-100…

Since the thermal history of the Universe is unknown before the epoch of primordial nucleosynthesis, the largest temperature of the radiation dominated phase (the reheating temperature) might have been as low as 1 MeV. We perform a…

We investigate Hawking evaporation of a population of primordial black holes (PBHs) prior to Big Bang Nucleosynthesis (BBN) as a mechanism to achieve asymmetric reheating of two sectors coupled solely by gravity. While the visible sector is…

We show that the relic abundance of the minority component of asymmetric dark matter can be very sensitive to the expansion rate of the Universe and the temperature of transition between a non-standard pre-Big Bang Nucleosynthesis…

We investigate the relic abundance of asymmetric Dark Matter particles that were in thermal equilibrium in the early universe. The standard analytic calculation of the symmetric Dark Matter is generalized to the asymmetric case. We…

We study a mechanism where the dark matter number density today arises from asymmetries generated in the dark sector in the early universe, even though total dark matter number remains zero throughout the history of the universe. The dark…

We investigate the relic abundance of asymmetric Dark Matter where the asymmetric Dark Matter is non--thermally produced from the decay of heavier particles in addition to the usual thermal production. We discuss the relic density of…

Dark matter may be coupled to dark radiation: light degrees of freedom that mediate forces between dark sector particles. Cosmological constraints favor dark radiation that is colder than Standard Model radiation. In models with fixed…

We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component…

Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM…