# Novel self-similar rotating solutions of non-ideal transverse magnetohydrodynamics

## TL;DR

This paper derives and analyzes new self-similar solutions in non-ideal transverse magnetohydrodynamics, revealing rotating and non-rotating electromagnetic field configurations and their dependence on medium properties.

## Contribution

It introduces two novel self-similar solutions for non-ideal transverse MHD, including a boost-invariant non-rotating and a non-boost-invariant rotating solution.

## Key findings

- Rotating solutions exhibit increasing angular velocity with rapidity.
- Electric conductivity and susceptibilities influence electromagnetic field evolution.
- Field lifetime and temperature evolution depend on angular velocity .

## Abstract

The evolution of electromagnetic and thermodynamic fields in a non-ideal fluid are studied in the framework of ultrarelativistic transverse magnetohydrodynamics (MHD), which is essentially characterized by electric and magnetic fields being transverse to the fluid velocity. Extending the method of self-similar solutions of relativistic hydrodynamics to the case of non-conserved charges, the differential equations of non-ideal transverse MHD are solved, and two novel sets of self-similar solutions are derived. The first set turns out to be a boost-invariant and exact solution, which is characterized by non-rotating electric and magnetic fields. The second set is a non-boost-invariant solution, which is characterized by rotating electric and magnetic fields. The rotation occurs with increasing rapidity $\eta$, as the angular velocity is defined by $\omega_{0}\equiv\frac{\partial\zeta}{\partial\eta}=\frac{\partial\phi}{\partial\eta}$, with $\zeta$ and $\phi$ being the angles of electric and magnetic vectors with respect to a certain axis in the local rest frame of the fluid. For both sets of solutions, the electric and magnetic fields are either parallel or anti-parallel to each other. Performing a complete numerical analysis, the effects of finite electric conductivity as well as electric and magnetic susceptibilities of the medium on the evolution of rotating and non-rotating MHD solutions are explored, and the interplay between the angular velocity $\omega_{0}$ and these quantities is scrutinized. The lifetime of electromagnetic fields and the evolution of the temperature of the electromagnetized fluid are shown to be affected by $\omega_{0}$.