Following the basic prescriptions of the Tsallis’ nonextensive thermodynamics, we study the relativistic nonextensive thermodynamics and the equation of state for a perfect gas at the equilibrium. The obtained results are used to study the relativistic nuclear equation of state in the hadronic and in the quark-gluon plasma phase. We show that small deviations from the standard extensive statist...

We study the effect of the solitonic degree of freedom in string cosmology following the line Rama. The gas of solitonic p-brane is treated as a perfect fluid in a Brans-Dicke type theory. In this paper, we find analytic solutions for a few solvable cases of equation of states with general Brans-Dicke parameter ω and study the cosmology of the solutions. In some cases the solutions are free fro...

We apply the method of time-dependent rescalings which has been developed by G. Rein and the author to a model kinetic equation, to the Euler equations for a perfect polytropic gas and to a model with friction and heat transfer. We build Lyapunov functionals which are in the case of the uid models improved versions of the estimates which have been found by J.-Y. Chemin and D. Serre (see 2], 14]).

The energy-Casimir method is applied to the problem of symmetric stability in the context of a compressible, hydrostatic planetary atmosphere with a general equation of state. Formal stability criteria for symmetric disturbances to a zonally symmetric baroclinic flow are obtained. In the special case of a perfect gas the results of Stevens (1983) are recovered. Finite-amplitude stability condit...

We apply the method of time-dependent rescalings which has been developed by G. Rein and the author to a model kinetic equation, to the Euler equations for a perfect polytropic gas and to a model with friction and heat transfer. We build Lyapunov functionals which are in the case of the uid models improved versions of the estimates which have been found by J.-Y. Chemin and D. Serre (see 2], 14]).

In the present paper a multigrid technique for three-dimensional perfect gas hypersonic vis-cous ows has been developed, employing a Total Variation Diminishing (TVD) discretization and an upwind correction prolongation, based on a monotonic reconstruction of coarse-grid correction. The methodology has good convergence properties, both for boundary layer ows and complex shock wave-boundary laye...

13. The introduction of a second new hypothetical gas. In the foregoing sections, we have investigated some transonic fields of flow by employing a hypothetical gas which closely approximates the real gas during an isentropic flow in the transonic range. Although such a hypothetical gas has a merit that the fundamental equation governing its flow assumes a rather simple form and can be solved e...

We investigate newtonian description of accreting compact bodies with hard surfaces, including luminosity and selfgravitation of polytropic perfect fluids. This nonlinear integro-differential problem reduces, under appropriate boundary conditions, to an algebraic relation between luminosity and the gas abundance in stationary spherically symmetric flows. There exist, for a given luminosity, asy...

Let (G;N) be a pair of groups. In this article, first we con-struct a relative central extension for the pair (G;N) such that specialtypes of covering pair of (G;N) are homomorphic image of it. Second, weshow that every perfect pair admits at least one covering pair. Finally,among extending some properties of perfect groups to perfect pairs, wecharacterize covering pairs of a perfect pair (G;N)...