Related papers: Dark Radiation from a hidden U(1)
Polarimetric experiments driven by the strong field of a circularly polarized laser wave can become a powerful tool to limit the parameter space of not yet detected hidden-photons and minicharged particles associated with extra U(1) gauge…
We show that a scalar and a fermion charged under a global U(1) symmetry can not only explain the existence and abundance of dark matter (DM) and dark radiation (DR), but also imbue DM with improved scattering properties at galactic scales,…
There is a large and growing interest in observations of small-scale structure in dark matter. We propose a new way to probe dark matter structures in the $\sim 10 - 10^8 \, M_\odot$ range. This allows us to constrain the primordial power…
The existence of millicharged dark matter (mDM) can leave a measurable imprint on 21-cm cosmology through mDM-baryon scattering. However, the minimal scenario is severely constrained by existing cosmological bounds on both the fraction of…
We study constraints from Big Bang Nucleosynthesis on inert particles in a dark sector which contribute to the Hubble rate and therefore change the predictions of the primordial nuclear abundances. We pay special attention to the case of…
We investigate cosmological and astrophysical constraints on dark photons with masses $\sim 10^{-1}$-$10^3$ MeV. These dark photons can be copiously produced either in the early universe or during core-collapse supernovae, potentially…
It is assumed that heavy dark matter particles $\phi$ with O(TeV) mass captured by the Sun may decay to relativistic light milli-charged particles (MCPs). These MCPs could be measured by the IceCube detector. The massless hidden photon…
From measurements of the cosmic microwave background (CMB), the effective number of neutrino is found to be close to the standard model value Neff = 3.046 for the \LambdaCDM cosmology. One can obtain the same CMB angular power spectrum as…
The resonant conversion, within the inter-galactic medium, of regular photons into dark photons amplifies the anisotropy observed in the CMB, thereby imposing stringent constraints on the existence of light dark photons. In this study, we…
The non-observation of dark matter (DM) by direct detection experiments suggests that any new interaction of DM with the Standard Model (SM) should be very weak. One of the simplest scenarios to achieve this is a dark sector that is charged…
Our understanding of the Universe today includes overwhelming observational evidence for the existence of an elusive form of matter that is generally referred to as dark. Although many theories have been developed to describe its nature,…
We reexamine the limits on charged dark matter particles. We show that if their mass and charge fall in the range 100(q_X/e)^2< m_X < 10^8(q_X/e) TeV, then magnetic fields prevent particles in the halo from entering the galactic disk, while…
We study the production of exotic millicharged particles (MCPs) from cosmic ray-atmosphere collisions which constitutes a permanent MCP production source for all terrestrial experiments Our calculation of the MCP flux can be used to…
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…
We have constrained the charge-mass ($\varepsilon-m$) phase space of millicharged particles through the simulation of the rotational evolution of neutron stars, where an extra slow-down effect due to the accretions of millicharged dark…
The similarity between the dark matter and baryon energy densities suggests an existence of a dark sector analogous to QCD. In addition, small-scale structure anomalies can be addressed by dark matter self-interactions with cross sections…
Many difficulties are encountered when attempting to pinpoint a common origin for several observed astrophysical anomalies, and when assessing their tension with existing exclusion limits. These include systematic uncertainties affecting…
Common extensions of the Standard Model of particle physics predict the existence of a "hidden" sector that comprises particles with a vanishing or very weak coupling to particles of the Standard Model (visible sector). For very light (m <…
We show that if dark energy evolves in time, its dynamical component could be dominated by a bath of dark radiation. Within current constraints this radiation could have up to $\sim 10^4$ times more energy density than the cosmic microwave…
Minimal atomic dark matter with its distinctive cooling mechanisms offers an instructive framework for understanding the potential impact of dark matter on small-scale structure formation and early cosmology. The model consists of two…