Non-relativistic limit analysis of the Chandrasekhar–Thorne relativistic Euler equations with physical vacuum

Abstract

Our results provide a first step to make the formal analysis rigorous in terms of [Formula: see text] proposed by Chandrasekhar [S. Chandrasekhar, The post-Newtonian equations of hydrodynamics in general relativity, Astrophys. J. 142 (1965) 1488–1512; S. Chandrasekhar, post-Newtonian equations of hydrodynamics and the stability of gaseous masses in general relativity, Phys. Rev. Lett. 14 (1965) 241–244], motivated by the methods of Einstein, Infeld and Hoffmann, see Thorne [K. S. Thorne, The general-relativistic theory of stellar structure and dynamics, in Proc. Int. School of Physics “Enrico Fermi,” Course XXXV, at Varenna, Italy, July 12–24, 1965, ed. L. Gratton (Academic Press, 1966), pp. 166–280]. We consider the non-relativistic limit for the local smooth solutions to the free boundary value problem of the cylindrically symmetric relativistic Euler equations when the mass energy density includes the vacuum states at the free boundary. For large enough (rescaled) speed of light [Formula: see text] and suitably small time [Formula: see text] we obtain uniform, with respect to [Formula: see text] “a priori” estimates for the local smooth solutions. Moreover, the smooth solutions of the cylindrically symmetric relativistic Euler equations converge to the solutions of the classical compressible Euler equation at the rate of order [Formula: see text].

Immediate blowup of classical solutions to the vacuum free boundary problem of non-isentropic compressible Navier--Stokes equations

“…In the case of viscous flows, the extra viscosities bring more regularities to the velocity field. Consequently, the degeneracy is comparably causing fewer troubles; see [35,31,23,16,28,58,32,44,40,14] for the isentropic flows.…”