Local Universe tests of gravity and dark energy

引力和暗能量的局部宇宙测试

• 批准号: 426574938
• 负责人: Dr. Noam Isaac Libeskind
• 金额: --
• 依托单位: Leibniz-Institut für Astrophysik Potsdam (AIP)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/426574938?language=en
• 关键词: Local; Universe; tests; gravity; dark

One of the most startling discoveries of 21st century astrophysics is that the expansion of the universe is accelerating. Cosmologists have zeroed in on two possible explanations for this challenge: the widely accepted paradigmatic hypothesis is that a cosmological constant (vacuum energy) drives the universe towards increasing its rate of expansion. Despite wide acceptance of this theory in the community, no one knows the true physical nature of the so called “dark energy".A more unorthodox notion is that the law of gravity — general relativity — may be modified on large scales. In this project we aim to test the latter by studying in great detail the formation of the local universe and to use the local universe as a cosmological laboratory to study the nature of gravity and dark energy.Specifically we aim to run constrained simulations of the local universe assuming both hypotheses but focusing on the effect of modifications to gravity, in an effort to provide new independent ways of ruling one in or out. Constrained simulations are cosmological simulations of structure formation where the initial conditions have been constrained by observational data, such that the final result is destined to reproduce the observed cosmographic landscape. Such simulations allow cosmologists to directly model the environment of the Milky Way and Local Group, instead of simulating random statistically similar structures. The German side is a world leader in running and analysing such simulations, while the Polish side is a world leader in testing theories of modified gravity. By combining our expertise we will, for the first time, be able to produce models of the Local Universe under the assumption that the laws of general relativity, one of the foundations of modern physics that has stood prime for over a century, are only an approximation to nature, revealed on small scales. Our project will have a major impact in both the fields of galaxy and structure formation (addressing question of how the local group and local universe formed), as well as in the field of modified gravity ruling in or out specific models that have been put forth in the literature.The value of our cooperation is straight forward: only by combing our complementary expertise is such a study possible. Furthermore because our expertise is so complementary we envision lasting knowledge transfer between the Polish and German side with the German side gaining permanent expertise in modified gravity and the Polish side becoming a player in constrained simulations.In sum, this project - LUSTRE (Local UniverSe Tests of gRavity and dark Energy) - aims at using the Local Universe as a cosmological laboratory to probe the fundamental physics of general relativity and cosmic acceleration.

21世纪世纪天体物理学最令人震惊的发现之一是宇宙正在加速膨胀。宇宙学家们已经将注意力集中在两种可能的解释上：一种被广泛接受的范式假设是宇宙常数（真空能量）驱动宇宙增加其膨胀率。尽管这个理论在社会上被广泛接受，但没有人知道所谓的“暗能量”的真正物理性质。一个更非正统的概念是，引力定律-广义相对论-可以在大尺度上修改。在这个项目中，我们的目标是通过详细研究局域宇宙的形成来测试后者，并将局域宇宙用作宇宙学实验室来研究引力和暗能量的性质。具体来说，我们的目标是在假设两种假设的情况下运行局域宇宙的约束模拟，但重点是引力修改的影响，以努力提供新的独立方法来排除一个。约束模拟是结构形成的宇宙学模拟，其中初始条件已被观测数据约束，使得最终结果注定要再现观测到的宇宙景观。这种模拟允许宇宙学家直接模拟银河系和本星系群的环境，而不是模拟随机的统计相似结构。德国方面在运行和分析此类模拟方面处于世界领先地位，而波兰方面在测试修正引力理论方面处于世界领先地位。通过结合我们的专业知识，我们将第一次能够在广义相对论定律的假设下产生本地宇宙的模型，广义相对论定律是现代物理学的基础之一，它已经存在了一个世纪，只是在小尺度上揭示的近似自然。我们的项目将在星系和结构形成领域（解决局部群和局部宇宙如何形成的问题）以及修正引力领域产生重大影响，这些领域将纳入或排除文献中提出的特定模型。我们合作的价值是直接的：只有结合我们互补的专业知识，这样的研究才有可能。此外，由于我们的专业知识是如此互补，我们设想波兰和德国方面之间的持久知识转移，德国方面获得修改重力的永久专业知识，波兰方面成为约束模拟的参与者。本项目- LUSTRE（引力和暗能量的局部宇宙测试）目的是利用本地宇宙作为宇宙学实验室，探索广义相对论和宇宙加速的基本物理学。