General relativistic theory of spin-fluid accretion disks around Black Holes

黑洞周围自旋流体吸积盘的广义相对论理论

• 批准号: 451018747
• 负责人: Professor Dr. Claus Lämmerzahl
• 金额: --
• 依托单位: Zentrum für angewandte Raumfahrttechnologie und Mikrogravitation (ZARM)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/451018747?language=en
• 关键词: General; relativistic; theory; spin; fluid

Since accretion disks can approach Black Holes very closely they are an important tool to investigate the strong gravity or the near horizon regime. The behavior of accretion disks depends on the material the disks is made of as well as on the space-time geometry. Usually accretions disks are modeled either by an ideal fluid with mass density and pressure or -- in order to account for the accretion process -- with viscosity. Also charged fluids or plasma have been discussed. Since interstellar matter -- in particular in strong gravity regions -- may consist of atoms or elementary particles it might be conceivable that also the spin or the magnetic moment of these atomic or sub-atomic constituents may play a role in the behavior of accretion disks. Accordingly, the present proposal discusses spin fluids as matter model for accretion disks. Compared with the usually assumed matter models, here additional couplings of the spin to the space-time curvature and to external electromagnetic fields of, e.g., galactic origin will be present and probably influence the physical properties of the disk. Spin also offers a preferred tool to search for a hypothetical space-time torsion. Beside that, spin fluids also ask for dedicated studies of the hyperbolicity of the equations of motion and, consequently, of causality. A further aspect is the need to implement supplementary spin conditions which may influence the equations of motion and, thus, also the hyperbolicity. These properties may also depend on the existence of a hypothetical torsion. The final aim of this project then is to calculate the physical properties of accretion disk, that is, its shape, the density profile, oscillations, and other characteristics.

由于积聚磁盘可以非常接近黑洞，它们是研究强力或近地平线状态的重要工具。积聚磁盘的行为取决于磁盘所制成的材料以及时空几何形状。通常，积聚磁盘是由具有质量密度和压力的理想流体进行建模的，或者 - 为了考虑粘度的增值过程。还讨论了带电的液体或血浆。由于星际物质 - 尤其是在强力区域中 - 可能由原子或基本颗粒组成，因此可能可以想象，这些原子或亚原子成分的自旋或磁矩可能在积聚磁盘的行为中起作用。因此，本提案讨论了旋转液作为积聚磁盘的物质模型。与通常假定的物质模型相比，在这里，自旋与时空曲率和外部电磁场的其他耦合将存在，例如，银河系来源，可能会影响磁盘的物理性质。 Spin还提供了搜索假设时空扭转的首选工具。除此之外，自旋流体还要求对运动方程的双曲线以及因果关系进行专门研究。另一个方面是需要实施补充自旋条件，这可能会影响运动方程，从而影响双曲线。这些特性也可能取决于假设扭转的存在。然后，该项目的最终目的是计算积聚磁盘的物理特性，即其形状，密度曲线，振荡和其他特征。