相关论文: Direct millicharged dark matter cannot explain EDG…

Millicharged particles are generic in theories of dark sectors. A cosmic or local abundance of them may be produced by the early universe, stellar environments, or the decay or annihilation of dark matter/dark energy. Furthermore, if such…

The mass of the dark matter particle is unknown, and may be as low as ~$10^{-22}$ eV. The lighter part of this range, below ~eV, is relatively unexplored both theoretically and experimentally but contains an array of natural dark matter…

At a level too faint for astronomy, particle dark matter may interact with Standard Model states via the photon. We derive limits from direct detection experiments on photon-mediated nuclear interactions up to operator dimension-6, viz.,…

Dark and baryonic matter contribute comparable energy density to the present Universe. The dark matter may also be responsible for the cosmic positron/electron excesses. We connect these phenomena with Dirac seesaw for neutrino masses. In…

We study the validity of effective field theory (EFT) interpretations of monojet searches for dark matter at the LHC for vector and axial-vector interactions. We show that the EFT approach is valid when the mediator has mass m_med greater…

This theoretical particle physics thesis is an investigation into old and new symmetries of Nature. Known symmetries and conservation laws serve as a guide for dark and visible sector model building. New symmetries of Nature are proposed,…

The identity of dark matter is being sought with increasingly sensitive and voluminous underground detectors. Recently the XENON1T collaboration reported excess electronic recoil events, with most of these having recoil energies around…

The first data from the LHC Run-2 have shown a possible excess in diphoton events with invariant mass $\sim 750$ GeV, suggesting the existence of a new resonance which may decay dominantly into dark matter (DM) particles. We show in a…

We consider nuclear gamma decays and $\gamma$-emitting reactions that can be an efficient source of hypothetical millicharged particles ($\chi$). In particular, we revisit the production of millicharged particles in nuclear reactor…

Models of scalar field dark matter where the scalar is a dilaton have a special behaviour, since non-trivial couplings, $d$, to matter result in a contribution to the potential for the field which is proportional to the trace of the…

We focus on exploring the metal enrichment of the intergalactic medium (IGM) in Cold and Warm (1.5 and 3 keV) Dark Matter (DM) cosmologies, and the constraints this yields on the DM particle mass, using a semi-analytic model, Delphi, that…

We investigate the cosmological stability of light bosonic dark matter carrying a tiny electric charge. In the wave-like regime of high occupation numbers, annihilation into gauge bosons can be drastically enhanced by parametric resonance.…

A new concept of generation of the cosmological baryon excess along with the cold dark matter (CDM) in the Universe is proposed and corresponding scenarios are outlined. Possible realizations of the idea in the framework of supersymmetric…

We investigate the production of electrons and positrons in the Milky Way within the context of dark matter annihilation. Upper limits on the relevant cross-section are obtained by combining observational data at different wavelengths (from…

We propose a possible explanation for the recent claim of an excess at 3.5 keV in the X-ray spectrum within a minimal extension of the standard model that explains dark matter and baryon abundance of the universe. The dark matter mass in…

The particle origin of dark matter (DM) remains elusive despite decades of direct, indirect, and collider searches. Several groups have reported a $\gamma$-ray excess toward the Galactic Centre, commonly referred to as the Galactic Centre…

We propose a mechanism of elementary thermal dark matter with mass up to $10^{14}$ GeV, within a standard cosmological history, whose relic abundance is determined solely by its interactions with the Standard Model, without violating the…

Right-handed neutrinos with MeV to GeV mass are very promising candidates for dark matter (DM). Not only can they solve the missing satellite puzzle, the cusp-core problem of inner DM density profiles, and the too-big-to fail problem, {\it…

In concordance cosmology, dark matter density perturbations generated by inflation lead to nonlinear, virialized minihalos, into which baryons collapse at redshift $z \sim 20$. We survey here novel baryon evolution produced by a…

We investigate the relic density n_\chi of non-relativistic long-lived or stable particles \chi in non-standard cosmological scenarios. We calculate the relic abundance starting from arbitrary initial temperatures of the radiation-dominated…