Condensation of slow $\gamma$-quanta in strong magnetic fields

TL;DR

This paper explores how strong magnetic fields near quantum electrodynamics thresholds cause vacuum birefringence, leading to anisotropic blackbody radiation and a novel condensate-like state that could affect neutron star stability.

Contribution

It introduces the concept of a resonance in the thermal spectrum caused by vacuum polarization effects in strong magnetic fields, revealing a new state of radiation.

Findings

Vacuum birefringence causes anisotropic Planck radiation.

A resonance in the spectrum leads to a crossover in low gamma-spectrum.

A condensate-like state of radiation may exist in neutron star cores.

Abstract

The implications of the root singularity of the vacuum polarization tensor near the first pair creation threshold on blackbody radiation are investigated for magnetic fields above the characteristic scale of quantum electrodynamics. We show that the vacuum birefringence in such a strong background leads to an anisotropic behavior of the Planck radiation law. The thermal spectrum is characterized by a resonance that competes with the Wien maximum, causing a crossover in the low $\gamma$-spectrum of the heat radiation. A light state resembling a many-body condensate with slow motion is linked to the high-temperature phase. This novel state of radiation may coexist with nuclear or quark matter in a neutron star's core, increasing its compactness and influencing its stability.