相关论文: Non-thermal Dark Matter from Modified Early Matter…

We study inelastic dark matter produced via freeze-in through a light mediator with a mass splitting below the electron-positron threshold. In this regime, the heavier dark matter state is naturally long-lived compared to the age of the…

In popular cold dark matter cosmological scenarios, stars may have first appeared in significant numbers around a redshift of 10 or so, as the gas within protogalactic halos with virial temperatures in excess of 20,000 K (corresponding to…

Dark matter(DM) is the only possible candidate which would be apart from the thermal equilibrium before Big Bang nucleosynthesis(BBN) in accordance with current DM searches. In this work, we report a generic scenario that primordial…

In this paper we present a novel mechanism for producing the observed Dark Matter(DM) relic abundance during the First Order Phase Transition (FOPT) in the early universe. We show that the bubble expansion with ultra-relativistic velocities…

Standard lore states that there is tension between the need to accommodate the relic density of a weakly interacting massive particle and direct searches for dark matter. However, the estimation of the relic density rests on an…

We summarize here our studies \cite{Chu:2022xuh,Chu:2023jyb,Chu:2024rrv} on two distinct scenarios for MeV-mass thermal dark matter freeze-out. First, we determine the minimal viable mass for dark matter below tens of MeV, considering…

Long-lived sterile neutrinos can play the role of dark matter. We consider the possibility that such neutrinos form a thermal bath with a singlet scalar, while not being in thermal equilibrium with the Standard Model fields. Eventually, the…

We illustrate, via a simplified model, a scenario in which the baryon-asymmetry and, possibly the dark matter component of the Universe are simultaneously generated by the decay of a WIMP-like mother particle, in turn produced non-thermally…

We consider a class of models in which thermal dark matter is lighter than an MeV. If dark matter thermalizes with the Standard Model below the temperature of neutrino-photon decoupling, equilibration and freeze-out cools and heats the…

We analyze the phenomenology of a prolonged early epoch of matter domination by an unstable but very long-lived massive particle. This new matter domination era can help to relax some of the requirements on the primordial inflation. Its…

We investigate models in which a spectrum of black holes with Hawking temperature of order the radiation temperature at the beginning of the radiation dominated era can survive long enough to produce a matter dominated era at the observed…

We present a minimal extension of the standard model that includes a long-lived fermion with weak-scale mass and an ${\cal O}({\rm GeV})$ fermionic dark matter candidate both of which are coupled to quarks. Decays of a TeV-scale colored…

In models of Asymmetric Dark Matter (ADM) the relic density is set by a particle asymmetry in an analogous manner to the baryons. Here we explore the scenario in which ADM decouples from the Standard Model thermal bath during an early…

The non-thermal production of dark matter (DM) usually requires very tiny couplings of the dark sector with the visible sector and therefore is notoriously challenging to hunt in laboratory experiments. Here we propose a novel pathway to…

Thermal freeze-out is a prominent example of dark matter (DM) production mechanism in the early Universe that can yield the correct relic density of stable weakly interacting massive particles (WIMPs). At the other end of the mass scale,…

The generation of a kination-dominated phase by a quintessential exponential model is investigated and the parameters of the model are restricted so that a number of observational constraints (originating from nucleosynthesis, the present…

We demonstrate that dark matter interactions can profoundly influence stellar nucleosynthesis in the early universe by altering thermodynamic gradients and modifying nuclear reaction rates within primordial stars. Incorporating a dark…

Electron mass is known to modify at finite temperatures and densities. Weak nuclear processes have a great impact on electron mass which modifies in a statistical background. We demonstrate how the temperature change in electron mass is…

We introduce a novel mechanism where processes that preserve the number density of the dark sector set the relic density of a thermal particulate dark matter. In a relatively degenerate multipartite dark sector if there is a considerable…

We present a new paradigm for the production of the dark matter (DM) relic abundance based on the evaporation of early Universe primordial black holes (PBHs) themselves formed from DM particles. As a concrete realization, we consider a…