Related papers: Two-component millicharged dark matter and the EDG…
While the origin and composition of dark matter and dark energy remains unknown, it is possible that they might represent two manifestations of a single entity, as occurring in unified dark sector models. On the other hand, advances in our…
We explain the $e^+ e^-$ excess observed by the DAMPE Collaboration using a dark matter model based upon the Higgs triplet model and an additional hidden $SU(2)_X$ gauge symmetry. Two of the $SU(2)_X$ gauge bosons are stable due to a…
If a subdominant component of dark matter (DM) interacts via long-range dark force carriers it may cool and collapse to form complex structures within the Milky Way galaxy, such as a rotating dark disk. This scenario was proposed recently…
We discuss a simple theory predicting the existence of a Dirac dark matter candidate from gauge anomaly cancellation. In this theory, the spontaneous breaking of local baryon number at the low scale can be understood. We show that the…
The EDGES low-band experiment has measured an absorption feature in the cosmic microwave background radiation (CMB), corresponding to the 21 cm hyperfine transition of hydrogen at redshift $z \simeq 17$, before the era of cosmic…
If, during the early Universe epoch, the dark matter particle thermalizes in a hidden sector which does not thermalize with the Standard Model thermal bath, its relativistic thermal decoupling can easily lead to the observed relic density,…
Since the electric charge in the standard model is theoretically not quantized, we may have a variant of it, called dark charge. Similar to the electric charge, the dark charge neither commutes nor closes algebraically with $SU(2)_L$. The…
We study a non-thermal scenario in a two-Higgs doublet extension of the standard model (SM), augmented by an U(1)_{\rm B-L} gauge symmetry. In this set up, it is shown that the decay product of a weakly coupled scalar field just above the…
Exponential suppression or commonly known as the Boltzmann suppression in the number density of dark matter is the key ingredient for creating chemical imbalance prior to the usual thermal freeze-out. A degenerate/quasi-degenerate dark…
The nonbaryonic dark matter of the Universe might consist of new stable charged species, bound by ordinary Coulomb interactions in various forms of heavy neutral "dark atoms". The existing models offer natural implementations for the…
With the assistance of two extra groups, i.e., an extra hidden gauge group $SU(2)_D$ and a global $U(1)$ group, we propose a two component dark matter (DM) model. After the symmetry $SU(2)_D\times U(1)$ being broken, we obtain both the…
We explore the cosmology and phenomenology of millicharged and millicharge-like dark matter with masses from 1 eV to 10 keV and charges of $10^{-18}$ to $10^{-14}$. Dark matter in this mass range cannot be thermally produced, but can arise…
Standard Model with right handed neutrinos charged under additional $U(1)_{B-L}$ gauge symmetry offer solutions to both dark matter (DM) problem and neutrino mass generation, although constrained severely from relic density, direct search…
The relic abundance of light millicharged particles (MCPs) with the electric charge $e' = 5\cdot 10^{-5} e$ and with the mass slightly below or above the electron mass is calculated. The abundance depends on the mass ratio $\eta=m_X/m_e$…
We demonstrate that if the dark matter (DM) in the Universe contains multiple components,the interactions between the DM components may induce DM conversions. It is then possible that the lightest DM component with an annihilation cross…
The EDGES Collaboration has recently announced the detection of the 21-cm spectrum with an absorption profile centred at $78$ megahertz, of which the depth is deeper than that expected by the standard cosmological paradigm. To enrich the…
If dark matter is unstable and the mass is within GeV-TeV regime, its decays produce high-energy photons that give contribution to the extragalactic gamma-ray background (EGRB). We constrain dark matter decay by analyzing the 50-month EGRB…
Persistent excesses in the spectra of gamma rays from the galactic center and cosmic ray antiprotons can be explained by dark matter of mass $50\sim 65$\,GeV annihilating into $b$ quarks, but this is typically hard to reconcile with direct…
The positron excess observed by PAMELA and then confirmed by AMS 02 has intrigued the particle physics community since 2008. Various dark matter decay and annihilation models have been built to explain the excess. However, the bounds from…
The Experiment to Detect the Global Epoch of Reionization Signature (EDGES) recently reported a strong 21-cm absorption signal relative to the cosmic microwave background at $z \sim 18$. While its anomalous amplitude may indicate new…