标题： 关于广义Nariai时空中的准正则模态 显示英文标题

标题： On the quasinormal modes in generalized Nariai spacetimes

摘要： 准正则模是耗散系统的本征模。 例如，如果一个具有事件视界或宇宙视界的时空从其平衡状态被扰动，准正则模会作为阻尼振荡出现，其复频谱称为准正则频率，这些频率仅取决于定义时空几何的电荷，如质量、电荷和角动量。 数学上，这种准正则模的离散频谱源于必须对在这样的时空中传播的物理场施加某些边界条件。 在本文中，我们将考虑一个由二维德西特空间$dS_2$与任意数量的二维球面$S^2$直积组成的带电Nariai时空的高维推广，并研究自旋$s$场扰动在$s = 0, 1/2, 1$和$2$情况下的动力学行为。 导致准正则模的边界条件被分析，准正则频率被解析地获得。 显示英文摘要

摘要： Quasinormal modes are eigenmodes of dissipative systems. For instance, if a spacetime with an event or cosmological horizon is perturbed from its equilibrium state, quasinormal modes arise as damped oscillations with a spectrum of complex frequencies, called quasinormal frequencies, that depends just on the charges which define the geometry of the spacetime in which the perturbation is propagating, such as the mass, electric charge, and angular momentum. Mathematically, this discrete spectrum of quasinormal modes stems from the fact that certain boundary conditions must be imposed to the physical fields propagating in such a spacetime. In this thesis, we shall consider a higher-dimensional generalization of the charged Nariai spacetime that is comprised of the direct product of the two-dimensional de Sitter space, $dS_2$, with an arbitrary number of two-spheres, $S^2$, and investigate the dynamics of spin-$s$ field perturbations for $s = 0, 1/2, 1$ and $2$. The boundary conditions leading to quasinormal modes are analyzed and the quasinormal frequencies are analytically obtained.