BREAKDOWN OF THE LINEAR-APPROXIMATION IN THE PERTURBATIVE ANALYSIS OFHEAT-CONDUCTION IN RELATIVISTIC SYSTEMS

We analyze the effects of thermal conduction in a relativistic fluid j ust after its departure from spherical symmetry, on a time scale of th e order of relaxation time. Using first order perturbation theory, it is shown that, as in spherical systems, at a critical point the effect ive inertial mass density of a fluid element vanishes and becomes nega tive beyond that point. The impact of this effect on the reliability o f causality conditions is discussed. (C) 1998 Elsevier Science B.V.