2024/10/06 by Xiankai Pang, Pang, Xiankai, Qing-Quan Jiang +5 · 3 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.2410.04323
openalex publication_date 2024/10/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this work, we will explore the precession of particle spins in spherical spacetimes. We first argue that the geometrical optics (WKB) approximation is insufficient, due to the absence of a glory spot in the backward scattering of massless particles, making an analysis of spin precession necessary. We then derive the precession equation assuming the spin is parallel transported, which is supported by the sub-leading order of the WKB approximation. The precession equation applies to both massless and massive particles. For particles moving at the speed of light, we show that spin is always reversed after backward scattering in any spherically symmetric spacetime, confirming the absence of a glory spot for massless particles. Finally, we solve the precession equation for Schwarzschild and Reissner-Nordström spacetimes and discuss the spin precession of massive particles, particularly in the non-relativistic limit. We find that, in Schwarzschild spacetime, the spin precession for particles moving with very small velocities compared to the speed of light depends only on the deflection angle, while in Reissner-Nordström spacetime, it also depends on the black hole charge, as revealed by the expansion derived from the strong lensing approximation.