We study the property of matter in equilibrium with a static, spherically symmetric black hole in D-dimensional spacetime. It requires this kind of matter has an equation of state ω ≡ pr/ρ = −1/(1 + 2kn), k, n ∈ N, which seems to be independent of D. However, when we associate this with specific models, some interesting limits on space could be found: (i)D = 2 + 2kn while the black hole is surr...

Leung, Chan & Chu (2004) claimed that a previously neglected reheating effect makes a small but noticeable change to the process of cosmological recombination. We revisit this effect by considering a system consisting of both radiation and ionizing gas under adiabatic expansion. In the thermal equilibrium limit, due to the huge radiation background, only a fraction about 10 of the heat released...

The entropy of the observable universe is increasing. Thus, at earlier times the entropy was lower. However, the cosmic microwave background radiation reveals an apparently high entropy universe close to thermal and chemical equilibrium. A two-part solution to this cosmic initial entropy problem is proposed. Following Penrose, we argue that the evenly distributed matter of the early universe is...

We calculate the exact kinetic evolution of cosmic neutrinos during the epoch previous to Big Bang Nucleosynthesis, in the case when a large neutrino asymmetry exists. By solving numerically the Boltzmann kinetic equations for the neutrino distribution functions, we find the momentum-dependent corrections to the equilibrium spectrum of neutrinos and discuss their phenomenological implications. ...

The diffuse gamma-ray background radiation (GBR) at high Galactic latitudes could be dominated by inverse Compton scattering (ICS) of cosmic ray (CR) electrons on the cosmic microwave background radiation (CBR) and on starlight (SL) in an extended CR halo of our galaxy. Assuming the locally observed CR electron spectrum beyond a few GeV, which follows from equilibrium between Fermi acceleration...