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Gauge invariant fluid lagrangian and its application to cosmology

A. Sulaiman·T. P. Djun·L. T. Handoko
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Abstract

A lagrangian for relativistic fluid systems with matters inside is developed using gauge principle. In the model, the gauge boson represents the fluid field in a form $A_μ\equiv ε_μϕ$, where $ε_μ$ contains the fluid kinematics and $ϕ$ is an auxiliary field representing the fluid distribution. This leads to a new relativistic equation of motion for fluid, but which further coincides to the classical Euler equation at non-relativistic limit. The lagrangian is applied to model homogeneous universe as a bulk pure fluid system. Taking the simplest case of fluid with radial velocity and uniform distribution, the free energy density is calculated and its behaviour around Hubble distance is discussed.

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A. Sulaiman, T. P. Djun, L. T. Handoko. 2009-01-01. Gauge invariant fluid lagrangian and its application to cosmology. https://arxiv.org/abs/physics/0508086

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