The matter Lagrangian of an ideal fluid
Abstract
We show that the matter Lagrangian of an ideal fluid equals (up to a sign depending on its definition and on the chosen signature of the metric) the total energy density of the fluid, i.e. rest energy density plus internal energy density.
- Publication:
-
International Journal of Geometric Methods in Modern Physics
- Pub Date:
- 2021
- DOI:
- 10.1142/S0219887821500596
- arXiv:
- arXiv:2011.04175
- Bibcode:
- 2021IJGMM..1850059M
- Keywords:
-
- General relativity and gravitation;
- fundamental problems and general formalism;
- Lagrangians and variational principles;
- General Relativity and Quantum Cosmology
- E-Print:
- 5 pages, accepted for publication in: International Journal of Geometric Methods in Modern Physics (IJGMMP)