where a is the scale factor of the universe, ρ and p are the energy density and the pressure, respectively, of the perfect fluid of which a classical universe is usually assumed to be made of, κ = 0,±1 is the curvature index of the flat, closed, open universe, respectively, and γ is the constant adiabatic index of the cosmological fluid. Recently, Faraoni, proposed the “Riccati route” of solvin...

Radial pulsations of newborn neutron stars (protoneutron stars) are studied for a range of internal temperatures and entropies per baryon predicted by the existing numerical simulations. Protoneutron star models are constructed using a realistic equation of state of hot dense matter, and under various assumptions concerning stellar interior (large trapped lepton number, zero trapped lepton numb...

We present a comprehensive asteroseismic study of the double-mode high-amplitude δ Scuti star HD 187642 (RV Ari). The modelling includes some of the most recent techniques: 1) effects of rotation on both equilibrium models and adiabatic oscillation spectrum, 2) non-adiabatic study of radial and non-radial modes, 3) relationship between the fundamental radial mode and the first overtone in the f...

in the present study the adiabatic temperature of gaseous fuels were calculated and the influence of effective parameters of flame temperature was discussed. firstly, a new computational program named ftc (flame temperature calculations) was prepared to calculate the adiabatic flame temperature and then the effect of initial temperatures of combustion air and fuel, excess air content and oxygen...