Nonextensive thermostatistics can yield apparent magnetism

Abstract

Bacry [Phys. Lett. B 317, 523 (1993)] showed that, on the basis of a deformed Poincar\'e group, special relativity yields a nonadditive energy for large systems, i.e., a total energy (of the Universe) which would not be proportional to the number of particles. He consistently argued that this effect could explain (part of) the so-called dark matter. By considering noninteracting spins at thermal equilibrium in the presence of an external magnetic field, we show here that the recently introduced nonextensive (nonadditive) thermostatistics could account for a theoretically possible ``dark magnetism'' (the apparent number of spins being smaller or larger than the actual one).