Radiation in (2+1)-dimensions

Abstract

In this paper we discuss the radiation equation of state $p=\rho /2$ in (2+1)-dimensions. In (3+1)-dimensions the equation of state $p=\rho /3$ may be used to describe either actual electromagnetic radiation (photons) as well as a gas of massless particles in a thermodynamic equilibrium (for example neutrinos). In this work it is shown that in the framework of (2+1)-dimensional Maxwell electrodynamics the radiation law $p=\rho /2$ takes place only for plane waves, i.e. for $E=B$. Instead of the linear Maxwell electrodynamics, to derive the (2+1)-radiation law for more general cases with $E\ne B$, one has to use a conformally invariant electrodynamics, which is a 2+1-nonlinear electrodynamics with a trace free energy-momentum tensor, and to perform a volumetric spatial average of the corresponding Maxwell stress-energy tensor with its electric and magnetic components at a given instant of time $t$.

7 pages. Accepted for publication in Phys. Lett. B

References in corpus (2)

• Higher-dimensional black holes with a conformally invariant Maxwell source
• Cosmology in three dimensions: steps towards the general solution

Cited by in corpus (1)

• Three-dimensional black holes via Noether symmetries