Field Theory for Perfect String Fluids

TL;DR

This paper develops a field theory framework for perfect string fluids, unifying various fluid models and extending to anisotropic fluids and higher-dimensional branes, with applications to magnetohydrodynamics and superfluids.

Contribution

It introduces a comprehensive field theory description of perfect string fluids, linking hydrodynamics with Lagrangian formulations and extending to complex fluid systems.

Findings

Established a mapping between field theory and hydrodynamics for string fluids.

Showed ideal magnetohydrodynamics as a special case of perfect string fluids.

Proposed extensions to anisotropic fluids and higher-dimensional branes.

Abstract

We develop a field theory description of non-dissipative string fluids and construct an explicit mapping between field theory degrees of freedom and hydrodynamic variables. The theory generalizes both a perfect particle fluid and pressureless string fluid to what we call a perfect string fluid. Ideal magnetohydrodynamics is shown to be an example of the perfect string fluid whose equations of motion can be obtained from a particular choice of the Lagrangian. The Lagrangian framework suggests a straightforward extension of the perfect string fluid to more general anisotropic fluids describing higher dimensional branes such as domain walls. Other modifications of the Lagrangian are discussed which may be useful in describing relativistic superfluids and fluids containing additional currents.