#Divergence in curved space skin

#Divergence in curved space skin

Furthermore, much of the large-scale flow and magnetic field structures observed in these systems originate at the species skin depth, so this scale length must be retained in order to fully model these processes (Ohsaki et al. 2006 Li, Krasnopolsky & Shang 2011 Lingam & Mahajan 2015). The consideration of differential velocities among different species in plasmas has a profound influence on our understanding of many astrophysical scenarios such as magnetic braking and star formation, accretion discs, magnetic field evolution in neutron star crusts, dynamo mechanisms, etc (Goldreich & Reisenegger 1992 Mininni, Gómez & Mahajan 2003 Cumming, Arras & Zweibel 2004 Mahajan et al. In particular, if we hope to examine the role of relative velocity and temperature differences between the two species or to capture the differing dynamics between the microscale and macroscale, we must seek a model beyond GRMHD. However, the foundations of GRMHD severely limit the scope of the plasma dynamics it is capable of describing. The physical accessibility arising from magnetohydrodynamic approximations has considerably enhanced our ability to simulate the effects of magnetic fields near compact objects (Gammie, McKinney & Tóth 2003 Komissarov 2004 Hawley 2011 Bucciantini & Del Zanna 2012 Pu et al. These phenomena are typically investigated within the framework of general relativistic magnetohydrodynamics (GRMHD), a single fluid description for plasmas in curved space–time. The unique combination of relativistic plasma flows near the speed of light, temperatures potentially comparable to the electron rest-mass energy, and curved space–time effects requires extensive covariant modelling efforts. 2005 Sekiguchi & Shibata 2005 Shibata & Sekiguchi 2005a Shibata & Sekiguchi 2005b). The complex dynamics of a magnetized plasma in a strong gravitational field dictates the evolution of many astrophysical phenomena, encompassing stellar core collapse of massive stars to proto-neutron stars or black holes, accretion disc instability around black holes, jet formation, magnetic braking of differentially rotating neutron stars, magnetic reconnection, etc (Zwerger & Mueller 1997 Dimmelmeier, Font & Müller 2002 Akiyama et al. The robust nature of this form promotes studies into both vorticity generation and evolution and additionally reveals a fundamental conserved helicity in the plasmas around compact objects.īlackhole physics, accretion: accretion disc, plasmas, magnetic fields 1 INTRODUCTION Specifically, we detail the construction of three tools for characterizing plasmas in curved space–time (i) The unification of the flow vorticity with the magnetic field permits the derivation of a clear relationship between the two vorticities in curved space–time, particularly evident in pair plasmas (ii) The simplified characterization of plasma states provided by the formalism facilitates a description and analysis of a broad class of equilibria, and we have here delineated the physically valid regime of these solutions around black holes, along with finding an explicit equation of state which ensures generalized helicity conservation (iii) We explicitly extend to curved space–times the special relativistic incorporation of entropy into the magnetofluid vorticity, here constructing a grand generalized vorticity. We present the extension of the magnetofluid vortical formalism to a general relativistic framework and demonstrate the versatility of the model in providing insight into astrophysical plasmas beyond the capabilities of most contemporary models.