标题： 克尔-塔布-努特时空中的超辐射现象 显示英文标题

标题： Superradiance in the Kerr-Taub-NUT spacetime

摘要： 超辐射是场波在从带电或旋转黑洞反射时被放大的效应。 在本文中，我们研究了在一般的轴对称静态Kerr-Taub-NUT（Newman-Unti-Tamburino）时空中的超辐射散射的低能动力学，该时空表示同时具有引力磁单极矩（磁性质量）和引力磁偶极矩（角动量）的源。 我们得到了所有自旋扰动场的广义Teukolsky主方程。 这些方程被分离为角部分和径向部分。 角方程导致了推广的带有自旋权重的椭球谐函数，这些函数在Kerr时空中的相应函数进行了推广。 我们识别了一个有效自旋，它是频率（或能量）与NUT参数之间的耦合。 研究了径向波函数在视界附近和无限边界处的行为。 我们提供了低能可观测量的解析表达式，包括所有无质量场的发射率和截面，这些场具有自旋，包括标量、中微子、电磁场、Rarita-Schwinger场和引力波。 显示英文摘要

摘要： Superradiance is the effect of field waves being amplified during reflection from a charged or rotating black hole. In this paper, we study the low-energy dynamics of super-radiant scattering of massive scalar and massless higher spin field perturbations in a generic axisymmetric stationary Kerr-Taub-NUT (Newman-Unti-Tamburino) spacetime, which represents sources with both gravitomagnetic monopole moment (magnetic mass) and gravitomagnetic dipole moment (angular momentum). We obtain a generalized Teukolsky master equation for all spin perturbation fields. The equations are separated into their angular and radial parts. The angular equations lead to spin-weighted spheroidal harmonic functions that generalize those in Kerr spacetime. We identify an effective spin as a coupling between frequency (or energy) and the NUT parameter. The behaviors of the radial wave function near the horizon and at the infinite boundary are studied. We provide analytical expressions for low-energy observables such as emission rates and cross sections of all massless fields with spin, including scalar, neutrino, electromagnetic, Rarita-Schwinger, and gravitational waves.