Relativistic Hydrodynamics a brief review of classical and quantum fluids in relativistic astrophysics

TL;DR

This paper provides a comprehensive review of relativistic hydrodynamics, covering classical and quantum fluids, with applications to astrophysics and cosmology, aiming to serve as an educational resource for advanced students.

Contribution

It introduces fundamental concepts of relativistic hydrodynamics, explores quantum effects like superfluidity, and discusses their relevance to dark matter and gravity quantization.

Findings

Classical hydrodynamics extended to Lorentz symmetry.

Quantum effects in superfluids relevant to astrophysics.

Superfluidity as a potential pathway to quantize gravity.

Abstract

The objective of this work is to revisit fundamental aspects of relativistic hydrodynamics, aiming at the construction of a first course in relativistic hydrodynamics and its applications to astrophysics at the level of end of undergraduate course and beginning of graduate course. We aim to introduce more basic concepts of basic hydrodynamics, going through models analogous to gravity to the theory of superfluids, applying mainly to astrophysics and the cosmology of the dark universe. We review the classical hydrodynamics, Galileo symmetry and its extension to Lorentz Symmetry applied to fluids, enabling the analogy of fluids with space-time. We study the conservation of the momentum-energy tensor and the energy conditions of Hawking-Ellis. In the next sections we investigate quantum effects, in particular linked to superfluids, and we also sketch an application to dark matter. In this study, we conclude that superfluidity is one of the possible ways to quantize gravity.