相关论文: A multi-temperature universe can allow a sub-MeV d…
Multi-body dark matter annihilation is commonly expected to be suppressed by higher-order couplings and phase-space factors, therefore being ignored thus far. We show that, however, this does not hold for a class of nonthermal dark matter…
If dark matter consists of hidden-sector photons which kinetically mix with regular photons, a tiny oscillating electric-field component is present wherever we have dark matter. In the surface of conducting materials this induces a small…
Dark matter may be discovered through its capture in stars and subsequent annihilation. It is usually assumed that dark matter is captured after a single scattering event in the star, however this assumption breaks down for heavy dark…
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…
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…
We have developed a set of four fully coupled Boltzmann equations to precisely determine the relic density and temperature of dark matter by including three distinct sectors: dark matter, light scalar, and standard model sectors. The…
A Dark Sink uses dark-sector interactions to siphon energy from dark matter to lighter dark degrees of freedom, i.e. dark radiation. Here, we extend dark matter models containing a Dark Sink to sub-MeV masses. We consider a Dark Sink model…
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…
If Dark Matter is composed of hidden-sector photons that kinetically mix with photons of the visible sector, then Dark Matter has a tiny oscillating electric field component. Its presence would lead to a small amount of visible radiation…
Dark photon is a massive vector field which interacts only with the physical photon through the kinetic mixing. This coupling is assumed to be weak so that the dark photon becomes almost unobservable in processes with elementary particles,…
We consider a dark sector model containing stable fermions charged under an unbroken $U(1)$ gauge interaction, with a massless dark photon as force carrier, and interacting with ordinary matter via scalar messengers. We study its early…
Hidden sectors are ubiquitous in supergravity theories, in strings and in branes. Well motivated models such as the Stueckelberg hidden sector model could provide a candidate for dark matter. In such models, the hidden sector communicates…
The non-detection of dark matter may be attributed to the dark matter residing in a darker hidden sector. We explore the possibility that a hidden sector produced through the freeze-in mechanism, can further generate an even more hidden…
We study the mutual interaction between the dark sectors (dark matter and dark energy) of the Universe by resorting to the extended thermodynamics of irreversible processes and constrain the former with supernova type Ia data. As a…
Cosmological observations have revealed the existence of a dark matter sector, which is commonly assumed to be made up of one particle species only. However, this sector might be more complicated than we currently believe: there might be…
Mirror matter is a promising self-collisional dark matter candidate. Here we study the evolution of thermodynamical quantities in the early Universe for temperatures below ~100 MeV in presence of a hidden mirror sector with unbroken parity…
We explore a scenario that the dark matter is a boson condensate created by the misalignment mechanism, in which a spin 0 boson (an axion-like particle) and a spin 1 boson (the dark photon) are considered, respectively. We find that…
We propose a new application of single molecule magnet crystals: their use as "magnetic bubble chambers" for the direct detection of sub-GeV dark matter. The spins in these macroscopic crystals effectively act as independent nano-scale…
Hidden sectors in connection with GeV-scale dark forces and dark matter are not only a common feature of physics beyond the Standard Model such as string theory and SUSY but are also phenomenologically of great interest regarding recent…
Many extensions of the Standard Model of particle physics predict a parallel sector of a new U(1) symmetry, giving rise to hidden photons. These hidden photons are candidate particles for cold dark matter. They are expected to kinetically…