Related papers: Constraining D-foam via the 21-cm Line
Dark matter is postulated to be a neutral Dirac fermion, charged under a dark $U(1)_D$ gauge symmetry. Scalar partners of the quarks and leptons are also charged under $U(1)_D$. The dark gauge boson $Z_D$ and the dark Higgs boson $h_D$…
We discuss modifications of the thermal Dark Matter (DM) relic abundances in stringy cosmologies with D-particle space-time foamy backgrounds. As a result of back-reaction of massive DM on the background space-time, owing to its interaction…
We explore the interplay between lines in the gamma-ray spectrum and LHC searches involving missing energy and photons. As an example, we consider a singlet Dirac fermion dark matter with the mediator for Fermi gamma-ray line at 130 GeV. A…
It seems necessary to suppress, at least partially, the formation of structure on subgalactic scales. As an alternative to warm or collisional dark matter, I postulate a condensate of massive bosons interacting via a repulsive interparticle…
Dark matter (DM) which constitutes five-sixths of all matter is hypothesised to be a weakly interacting non-baryonic particle, created in the early stages of cosmic evolution. It can affect various cosmic structures in the Universe via…
Many theories about dark matter have emerged due to its strong theoretical appeal in explaining astrophysical phenomena. However, experimental and theoretical particle physics have yet not provided evidence that dark matter is part of the…
We consider a self-interacting dark matter model in which the massive dark photon mediating the self-interaction decays to light dark fermions to avoid over-closing the universe. We find that if the model is constrained to explain the dark…
In this work we investigate the possibility that dark matter and (massive) neutrinos can interact via a simple, constant cross section. Building on previous numerical efforts, we constrain this model with CMB, BAO and, in particular,…
We study some properties of the dark degeneracy, which is the fact that what we measure in gravitational experiments is the energy momentum tensor of the total dark sector, and any split into components (as in dark matter and dark energy)…
Fluctuations in the 21cm brightness from cosmic hydrogen at redshifts z > 6 were sourced by the primordial density perturbations from inflation as well as by the radiation from galaxies. We propose a method to separate these components…
Existence of new gauge U(1) symmetry possessed by dark matter (DM) particles implies the existence of a new Coulomb-like interaction, which leads to Sommerfeld-Gamow-Sakharov enhancement of dark matter annihilation at low relative…
The nature of dark matter remains obscure in spite of decades of experimental efforts. The mass of dark matter candidates can span a wide range, and its coupling with the Standard Model sector remains uncertain. All these unknowns make the…
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…
I discuss a model inspired from the string/brane framework, in which our Universe is represented as a three brane, propagating in a bulk space time punctured by D0-brane (D-particle) defects. As the D3-brane world moves in the bulk, the…
We study the cosmological predictions of the dark D-brane model, in which dark matter resides on a D-brane moving in a higher-dimensional space. By construction, dark matter interacts only gravitationally with the standard model sector in…
A possible manifestation of an additional light gauge boson $A^\prime$, named as Dark Photon, associated with a group $U(1)_{\rm B-L}$ is studied in neutrino electron scattering experiments. The exclusion plot on the coupling constant…
Dark matter (DM) with a mass below a few keV must have a phase space distribution that differs substantially from the Standard Model particle thermal phase space: otherwise, it will free stream out of cosmic structures as they form. We…
Kinetic mixing of the dark photon, the gauge boson of a hidden $U(1)_D$, with the Standard Model (SM) gauge fields to induce an interaction between ordinary matter and dark matter (DM) at 1-loop requires the existence of portal matter (PM)…
We examine the possibility that dark matter may be the manifestation of dark forces of a hidden sector, i.e. "Dark Force = Dark Matter." As an illustrative and minimal example we consider the hidden SU(2)_h x U(1)_h gauge group. The hidden…
Wave-like dark matter composed of spin-1 particles, known as dark photons, is theorized to form clumps called "vector solitons". These solitons are compact astrophysical objects that exhibit coherent oscillations and a high concentration…