Quasi-normal modes of rotating black holes in alternative theories of gravity

替代引力理论中旋转黑洞的准正态模式

• 批准号: 492628948
• 负责人: Professorin Dr. Jutta Kunz-Drolshagen
• 金额: --
• 依托单位: Institut für Physik (IFP)
• 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/492628948?language=en
• 关键词: Quasi; normal; modes; rotating; black

In recent years there has been enormous progress in the gravitation and astrophysics of compact objects. LIGO/VIRGO observations have opened the new window of gravitational wave multimessenger astronomy and provided first glimpses of such cataclysmic events as stellar type black hole and neutron star mergers. Such merger events can and will strongly improve our understanding of black holes and neutron stars on the one hand and gravity on the other. Black holes and neutron stars represent ideal laboratories to test general relativity and alternative theories of gravity because of their extreme compactness. Alternative gravitational theories typically introduce further degrees of freedom, with many featuring a gravitational scalar field. The compact objects in these theories can then differ substantially from their general relativity counterparts. The presence of a gravitational scalar field, for instance, yields a much richer gravitational wave spectrum, allowing also for scalar radiation. By requiring consistency with present and future observations, the presence of such new degrees of freedom can lead to important new constraints on these theories and test their viability. Quasi-normal modes have received much attention in recent years, since they describe gravitational waves emitted during the ringdown phase of merger events and should be quite well discernible by future gravitational wave detectors. Thus quasi-normal modes represent crucial observables. Moreover, quasi-normal modes reveal the linear stability of black holes or neutron stars. The research we propose aims at developing theoretical and numerical tools to obtain quasinormal modes in the case of slow (perturbative) and fast (nonperturbative) rotation, and to apply these tools to black holes in alternative gravity theories. Later these tools can be generalized for neutron stars. This will allow us to extract the relevant signatures of alternative gravity theories in the ringdown of rotating compact objects, providing new constraints on these theories.

近年来，在致密天体的万有引力和天体物理学方面取得了巨大进展。LIGO/VIRGO的观测打开了引力波多信使天文学的新窗口，并首次提供了恒星型黑洞和中子星合并等灾难性事件的瞥见。这样的合并事件一方面可以而且将会极大地提高我们对黑洞和中子星以及引力的理解。黑洞和中子星是检验广义相对论和其他引力理论的理想实验室，因为它们的密度极高。其他的引力理论通常会引入更多的自由度，其中许多都以引力标量场为特征。这些理论中的紧致物体与广义相对论中的紧致物体有很大的不同。例如，引力标量场的存在产生了更丰富的引力波频谱，也允许标量辐射。由于要求与当前和未来的观测结果保持一致，这些新自由度的存在可以对这些理论产生重要的新约束，并检验它们的可行性。准正态模式近年来受到了很多关注，因为它们描述了在合并事件的振荡阶段发射的引力波，未来的引力波探测器应该能很好地识别出来。因此，准正态模代表了关键的可观测值。此外，准正模揭示了黑洞或中子星的线性稳定性。我们提出的研究旨在开发理论和数值工具来获得慢（微扰）和快（非微扰）旋转情况下的准正态模态，并将这些工具应用于替代引力理论中的黑洞。以后这些工具可以推广到中子星上。这将使我们能够在旋转致密物体的环落中提取出替代引力理论的相关特征，为这些理论提供新的约束条件。