Related papers: Astroparticle Constraints from Cosmic Reionization…
We quantify the accuracy with which the cosmological parameters characterizing the energy density of matter (\Omega_m), the amplitude of the power spectrum of matter fluctuations (\sigma_8), the energy density of neutrinos (\Omega_{\nu})…
Theoretical studies and current observations of the high-redshift intergalactic medium (IGM) indicate that at least two cosmic transitions occur by the time the universe reaches gas metallicities of about $10^{-3}$ of solar values. These…
We present a complete analysis of the cosmological constraints on decaying dark matter. Previous analyses have used the cosmic microwave background and Type Ia supernova. We have updated them with the latest data as well as extended the…
We examine the effects of dark energy dynamics and spatial curvature on cosmic reionization by studying reionization in tilted spatially-flat and untilted non-flat XCDM and $\phi$CDM dynamical dark energy inflation models that best fit the…
We use a robust analytical model together with a high-resolution hydrodynamical cosmological simulation to demonstrate that in a $\Lambda$ cold dark matter ($\Lambda$CDM) universe, a small fraction of dwarf galaxies inhabiting dark matter…
Radiative feedback from stars and galaxies has been proposed as a potential solution to many of the tensions with simplistic galaxy formation models based on $\Lambda$CDM, such as the faint end of the UV luminosity function. The total…
Attenuation of high--energy gamma rays by pair--production with UV, optical and IR background photons provides a link between the history of galaxy formation and high--energy astrophysics. We present results from our latest semi-analytic…
Measurements of the galaxy UV luminosity function at z>6 suggest that young stars hosted in low-mass star-forming galaxies produced the bulk of hydrogen-ionizing photons necessary to reionize the intergalactic medium (IGM) by redshift z~6.…
We examine the constraints on soft X-ray emissions from the reionization era. It has generally been assumed that the Universe was reionized by ultraviolet photons from massive stars. However, it has been argued that X-ray photons associated…
We present an updated model of the cosmic ionizing background from the UV to the X-rays. Relative to our previous model (Faucher-Giguere et al. 2009), the new model provides a better match to a large number of up-to-date empirical…
While, to ensure successful cosmology, dark matter (DM) must kinematically decouple from the standard model plasma very early in the history of the Universe, it can remain coupled to a bath of "dark radiation" until a relatively late epoch.…
If a component of cosmological dark matter is made up of massive particles - such as sterile neutrinos - that decay with cosmological lifetime to emit photons, the reionization history of the universe would be affected, and cosmic microwave…
We use the Allen et al. (2008) galaxy cluster gas mass fraction versus redshift data to constrain parameters of three different dark energy models: a cosmological constant dominated one ($\Lambda$CDM); the XCDM parameterization of dark…
We present a simple UV completion of Atomic Dark Matter (aDM) in which heavy right-handed neutrinos decay to induce both dark and lepton number densities. This model addresses several outstanding cosmological problems: the…
Thanks to the successful performance of the James Webb Space Telescope, our understanding of the epoch of reionization of the Universe has been advanced. The ultraviolet luminosity functions (UV LFs) of galaxies span a wide range of…
We combine fast radiative transfer calculations with high resolution hydrodynamical simulations to study an epoch of early hydrogen reionisation by primordial stellar sources at redshifts 15<z<30. With relatively conservative assumptions,…
Many approaches to obtaining cosmological constraints rely on the connection between galaxies and dark matter. However, the distribution of galaxies is dependent on their formation and evolution as well as the cosmological model, and galaxy…
We use the photon flux and absorption tracer algorithm presented in Katz et al.~2018, to characterise the contribution of haloes of different mass and stars of different age and metallicity to the reionization of the Universe. We employ a…
We show that the process of photoionizing a gas of atomic hydrogen and helium by line radiation whose energy is slightly above the helium single-ionization threshold is unstable if the helium fraction by number is less than approximately…
Dark matter is poorly constrained by direct detection experiments at masses below 1 MeV. This is an important target for the next generation of experiments, and several methods have been proposed to probe this mass range. One class of such…