Gravitational waves from compact objects - a tool for testing strong gravity and nuclear matter at extreme densities

来自致密物体的引力波——一种在极端密度下测试强引力和核物质的工具

• 批准号: 406423933
• 负责人: Dr. Daniela Doneva, Ph.D.
• 金额: --
• 依托单位: Abteilung Theoretische Astrophysik
• 依托单位国家: 德国
• 项目类别: Independent Junior Research Groups
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/406423933?language=en
• 关键词: Gravitational; waves; compact; objects; tool

Gravity plays a central role in almost every grant challenge in astrophysics, cosmology and fundamental physics making it a subject to a strong interdisciplinarity. Recently there was a major breakthrough in the efforts to test the predictions of general relativity, namely the direct detection of gravitational waves. In the following years, an unprecedented view of previously invisible parts of the Universe will be opened through gravitational wave observations of mergers of the most compact objects known to exist in the universe - the neutron stars and the black holes. On another front, the accelerated expansion of the Universe, that is one of the most important open problems in physics nowadays, can be attributed to our lack of understanding of gravity on astrophysical and cosmological scales where the pure general relativity breaks down giving rise to a more complete theory of gravity. Modifications of Einstein's theory are predicted as well from the theories trying to unify all the interaction or the quantum corrections in the strong gravity regime. Moreover, general relativity is indeed tested with remarkable accuracy but only in the weak field regime, while the strong field regime is poorly explored and constrained. The aim of the current project is to perform a systematic effort in exploring the gravitational wave emission from merging neutron stars and black holes in generalized theories of gravity covering almost all stages of the merger: the inspiral, the post-merger phase and in some cases - the gravitational wave afterglow. We will cover a wide class of alternative theories of gravity that are theoretically well motivated and in agreement with the observations. This would be the first study of this magnitude since up to now mainly isolated results of some alternative theories of gravity or of certain mechanisms of gravitational wave emission were obtained. Using the above results as a basis, the second extremely important goal would be to break the degeneracy between equation of state uncertainties and uncertainties in the underlying gravitational theory for the gravitational wave observations of merging neutron stars. Most of the observational constraints on the equation of state, though, implicitly assume pure general relativity as the underlying theory of gravity. This poses serious difficulties in testing the alternative theories of gravity. Since one of the main goals of the future gravitational wave observations of merging neutron stars is to impose constraints on the behavior of matter at extreme densities, developing a methodology that is independent of the underlying theory of gravity is of great importance.

引力在天体物理学、宇宙学和基础物理学的几乎每一个重大挑战中都扮演着核心角色，使其成为一个强大的跨学科学科。最近，在检验广义相对论预言的努力中取得了重大突破，即直接探测到引力波。在接下来的几年里，通过引力波观测宇宙中已知存在的最致密物体——中子星和黑洞的合并，将打开宇宙中以前看不见的部分的前所未有的视野。另一方面，宇宙的加速膨胀，这是当今物理学中最重要的未决问题之一，可以归因于我们缺乏对天体物理学和宇宙尺度上的引力的理解，在这些尺度上，纯粹的广义相对论被打破，从而产生了一个更完整的引力理论。爱因斯坦理论的修正也可以从试图统一强引力下所有相互作用或量子修正的理论中得到预测。此外，广义相对论确实得到了非常精确的检验，但只是在弱场范围内，而对强场范围的探索和限制很少。当前项目的目的是在广义引力理论中进行系统的努力，探索中子星和黑洞合并时的引力波发射，涵盖几乎所有合并阶段：激励阶段，合并后阶段，在某些情况下-引力波余辉。我们将涵盖一系列广泛的引力理论，这些理论在理论上是有良好动机的，并且与观测结果一致。这将是第一次如此规模的研究，因为到目前为止，主要是获得了一些其他重力理论或引力波发射的某些机制的孤立结果。以上述结果为基础，第二个极其重要的目标将是打破合并中子星引力波观测中状态不确定性方程与基础引力理论不确定性之间的简并。然而，大多数状态方程的观测约束都隐含地假设纯广义相对论是引力的基本理论。这给检验其他引力理论带来了严重的困难。由于未来对合并中子星的引力波观测的主要目标之一是对极端密度下物质的行为施加约束，因此开发一种独立于基本引力理论的方法非常重要。