Spinning Equations for Objects of Some Classes in Finslerian Geometry

Spinning and Spinning Deviation Equations for Special Types of Gauge Theories of Gravity

The problem of spinning and spin deviation equations for particles as defined by their microscopic effect has led many authors to revisit non-Riemannian geometry for being described torsion and its relation with the spin of elementary particles. We obtain a new method to detect the existence of torsion by deriving the equations of spin deviations in different classes of non-Riemannian geometries, using a modified Bazanski method. We find that translational gauge potentials and rotational gauge potentials regulate the spin deviation equation in the presence of Poincare gauge field theory of gra…

Three dimensional stationary cyclic symmetric Einstein-Maxwell solutions; black holes

From a general metric for stationary cyclic symmetric gravitational fields coupled to Maxwell electromagnetic fields within the $(2+1)$-dimensional gravity the uniqueness of wide families of exact solutions is established, among them, all uniform electromagnetic solutions possessing electromagnetic fields with vanishing covariant derivatives, all fields having constant electromagnetic invariants $F_{μν}\,F^{μν}$ and $T_{μν}\,T^{μν}$, the whole classes of hybrid electromagnetic solutions, and also wide classes of stationary solutions are derived for a third order nonlinear key equations. Certai…

Scattering of Spinning Test Particles by Plane Gravitational and Electromagnetic Waves

The Mathisson-Papapetrou-Dixon (MPD) equations for the motion of electrically neutral massive spinning particles are analysed, in the pole-dipole approximation, in an Einstein-Maxwell plane-wave background spacetime. By exploiting the high symmetry of such spacetimes these equations are reduced to a system of tractable ordinary differential equations. Classes of exact solutions are given, corresponding to particular initial conditions for the directions of the particle spin relative to the direction of the propagating background fields. For Einstein-Maxwell pulses a scattering cross section is…

接近深渊的螺旋：Kerr时空中的近赤道坠落轨道自旋粒子解析解

Going into a tailspin near the abyss: analytic solutions for spinning particles on near equatorial, plunging orbits in Kerr spacetime

本文提出了Kerr时空中近赤道坠落轨道自旋粒子的解析解，解决了小质量自旋体的运动方程，并引入了新的开普勒式参数化方法。

Non-Spinning Black Holes in Alternative Theories of Gravity

We study two large classes of alternative theories, modifying the action through algebraic, quadratic curvature invariants coupled to scalar fields. We find one class that admits solutions that solve the vacuum Einstein equations and another that does not. In the latter, we find a deformation to the Schwarzschild metric that solves the modified field equations in the small coupling approximation. We calculate the event horizon shift, the innermost stable circular orbit shift, and corrections to gravitational waves, mapping them to the parametrized post-Einsteinian framework.

约束具有连续引力波的旋转变形银河系致密天体的丰度

Constraining the abundance of spinning deformed Galactic compact objects with continuous gravitational waves

本研究基于LIGO-Virgo未探测到连续引力波的数据，构建贝叶斯框架对银河系中高椭率奇异致密天体的数量上限进行约束，在90%置信度下给出了不同椭率条件下的丰度上限，并进一步对致密天体的椭率设定了限制。