Entropy (Oct 2021)

Inhomogeneous and Radiating Composite Fluids

  • Byron P. Brassel,
  • Sunil D. Maharaj,
  • Rituparno Goswami

DOI
https://doi.org/10.3390/e23111400
Journal volume & issue
Vol. 23, no. 11
p. 1400

Abstract

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We consider the energy conditions for a dissipative matter distribution. The conditions can be expressed as a system of equations for the matter variables. The energy conditions are then generalised for a composite matter distribution; a combination of viscous barotropic fluid, null dust and a null string fluid is also found in a spherically symmetric spacetime. This new system of equations comprises the energy conditions that are satisfied by a Type I fluid. The energy conditions for a Type II fluid are also presented, which are reducible to the Type I fluid only for a particular function. This treatment will assist in studying the complexity of composite relativistic fluids in particular self-gravitating systems.

Keywords