Related papers: Does CMB Distortion Disfavour Intermediate Mass Da…
The temperature and polarization anisotropies of the cosmic microwave background (CMB) have been used to set constraints on decaying dark matter models down to keV masses. In this work, we extend these limits down to the sub-keV mass range.…
Intermediate mass black holes (IMBHs), with masses between 100 to 10^5 M_\odot, represent the link between stellar mass black holes and the supermassive black holes that reside in galaxy centers. While IMBHs are crucial to our understanding…
Using both cosmic microwave background and large scale structure data, we put stringent bounds on the possible cold dark matter, baryon and neutrino isocurvature contributions to primordial fluctuations in the Universe. Neglecting the…
Observational searches for Intermediate-Mass Black Holes (IMBHs), defined to have masses between 30 and 300,000 solar masses, provide limits which allow up to ten percent of what is presently identified as halo dark matter to be in the form…
We study the prospects for detecting gamma-rays from Dark Matter (DM) annihilations in enhancements of the DM density (mini-spikes) around intermediate-mass black holes with masses in the range $10^2 \lsim M / \msun \lsim 10^6$. Focusing on…
Dark matter is a vital component of the current best model of our universe, $\Lambda$CDM. There are leading candidates for what the dark matter could be (e.g. weakly-interacting massive particles, or axions), but no compelling observational…
We consider a cosmological model in which a fraction $f$ of the Dark Matter (DM) is allowed to decay in an invisible relativistic component, and compute the resulting constraints on both the decay width (or inverse lifetime) $\Gamma$ and…
Baryon-density perturbations of large amplitude may exist if they are compensated by dark-matter perturbations so that the total density remains unchanged. Big-bang nucleosynthesis and galaxy clusters allow the amplitudes of these…
We derive new CMB anisotropy power spectrum and BBN constraints for evaporating primordial black holes by explicitly solving the electromagnetic particle cascades of emitted particles and the deposition of this emitted energy to the…
Primordial black holes (PBHs) are the plausible candidates for the cosmological dark matter. Theoretically, PBHs with masses $M_{\rm PBH}$ in the range of $4\times10^{14}\sim 10^{17}\,{\rm g}$ can emit sub-GeV electrons and positrons…
We examine cosmological, astrophysical and collider constraints on thermal dark matter (DM) with mass mX in the range 1 MeV to 10 GeV. Cosmic microwave background (CMB) observations, which severely constrain light symmetric DM, can be…
Many observed globular clusters (GCs) seem to show a central overabundance of mass whose nature has not yet fully understood. Indeed, it is not clear whether it is due to a central intermediate mass black hole (IMBH) or to a massive stellar…
We show scenarios in which primordial black hole accretion under the magnetorotational instability (MRI) uniquely relates the density of the early Universe to the abundance of present day dark matter. We demonstrate via long duration…
Intermediate Mass Black Holes (IMBHs) are a class of black holes with masses in the range $10^2 \div 10^5$ $M_\odot$, which can not directly derive from stellar evolution. Looking for these objects and estimating their abundance is…
This paper reviews the subject of intermediate-mass black holes (IMBHs) with masses between those of "stellar-mass" and "super-massive" black holes. The existence of IMBHs is a real possibility: they might plausibly have formed as remnants…
The small-scale crisis, discrepancies between observations and N-body simulations, may imply suppressed matter fluctuations on subgalactic distance scales. Such a suppression could be caused by some early-universe mechanism (e.g., broken…
The possibility of light dark matter (DM) annihilating through a dark photon (DP) which kinetically mixes (KM) with the Standard Model (SM) hypercharge field is a very attractive scenario. For DM in the interesting mass range below $\sim 1$…
The cosmic microwave background (CMB) spectrum is an extraordinary tool for exploring physics beyond the Standard Model. The exquisite precision of the measurement makes it particularly sensitive to small effects caused by hidden sector…
The dimming of Type Ia supernovae could be the result of Hubble-scale inhomogeneity in the matter and spatial curvature, rather than signaling the presence of a dark energy component. A key challenge for such models is to fit the detailed…
We propose that the massive compact halo objects (MACHOs) observed in the recent microlensing experiments with an apparent best fit mass of about $0.5 M_{\odot}$ are objects made out of ``mirror'' baryonic matter rather than familiar…