2018/05/31 by Maxim Dvornikov, Victor B. Semikoz · 10 citations
Physics and Astronomy · #Anomaly (physics) #Astrophysical Phenomena and Observations #Conservation law #Helicity #High-Energy Particle Collisions Research #Magnetic flux #Magnetic helicity #Neutron star #Pulsars and Gravitational Waves Research #Spin (aerodynamics) #Surface (topology) #astro-ph.HE #hep-ph
paper · pdf · doi:10.1088/1475-7516/2018/08/021
published in Journal of Cosmology and Astroparticle Physics 2018(08), 021 (Institute of Physics) · 16 pages in pdflatex, 1 pdf figure, jcap latex style; paper was significantly revised, Sec. 3 was extended, some notations were improved; version published in JCAP
openalex created_date 2018/05/17 · openalex publication_date 2018/08/16 · arxiv created 2018/08/17 · arxiv updated 2018/08/20 · openalex updated_date 2026/08/05
We analyze the role of the surface terms in the conservation law for the sum of the magnetic helicity density and the chiral imbalance of the charged particle densities. These terms are neglected in the Anomalous MagnetoHydroDynamics (AMHD), where infinite volume is considered typically. We discuss a finite volume system, such as a magnetized neutron star (NS), and study the contribution of the surface terms to the evolution of the magnetic helicity. Accounting for the fast washing out of the chiral imbalance in a nascent NS, we demonstrate that the surface terms contribution can potentially lead to the reconnection of magnetic field lines and subsequent gamma or X-ray bursts observed from magnetars. We derive the additional surface terms originated by the mean spin flux through a volume boundary arising due to macroscopic spin effects in electron-positron plasma. Then, comparing this quantum surface term with the classical one known in standard MHD, we find that the new quantum contribution prevails over classical term for the rigid NS rotation only.