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arXiv · 2309.00463

On the flow of perfect energy tensors

Juan Antonio Sáez·Salvador Mengual·Joan Josep Ferrando
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Abstract

The necessary and sufficient conditions are obtained for a unit time-like vector field $u$ to be the unit velocity of a divergence-free perfect fluid energy tensor. This plainly kinematic description of a conservative perfect fluid requires considering eighteen classes defined by differential concomitants of $u$. For each of these classes, we get the additional constraints that label the flow of a conservative energy tensor, and we obtain the pairs of functions $\{\rho,p\}$, energy density and pressure, which complete a solution to the conservation equations.

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Juan Antonio Sáez, Salvador Mengual, Joan Josep Ferrando. 2023-09-01. On the flow of perfect energy tensors. https://doi.org/10.1088/1361-6382%2Face584

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