DFG-NSF: Observational Tests of Covariant Emergent Gravity

广义相对论提供了一个在很大距离范围内的引力现象的经过充分测试的准确描述，但它仍然是一个与粒子物理学标准模型不相容的非量子理论。因此，发展量子引力理论是基础物理学的一个中心目标。观测的线索来自于诸如“暗物质”和“暗能量”等难题。这表明了一种超过星系中可见质量引力（因此是暗物质）所能解释的吸引力，以及一种净排斥力（暗能量），它驱动着宇宙的膨胀率加速。可以想象，这些不同的现象是相关的，并可能从引力的量子基础中出现。这项工作将发展和探索协变突现引力的可观测结果，该理论可能为这些尚未被理解的观测提供联合解释。该项目旨在发展和测试对暗物质和暗能量的新解释。Verlinde提出了引力作为一种涌现现象的想法，但这个想法的许多后果仍然没有被探索。一个理论上的缺点是它通常不是协变的。最近，Hossenfelder通过开发协变涌现引力（CEG）解决了这个问题。CEG必然会引入超越《涌现引力》中已有的术语。该团队建议发展这一理论，并研究CEG是否与星系旋转曲线的观测结果一致。特别是，它将推导出控制理论适当极限的公式，并数值求解它们以应用于真实的星系。这项工作必须进行的非平凡的，非球形的情况下，有限厚度的圆柱形的几何形状适合于螺旋星系。如果CEG假设是不正确的，这项工作应该很容易证明它是错误的。如果它有一些优点，它可能会为长期存在的暗物质和暗能量问题的新解释和潜在解决指明方向，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准。

General Relativity provides a well-tested, accurate description of gravitational phenomena over a large range of distances, but it remains a non-quantum theory incompatible with the Standard Model of particle physics. The development of a quantum theory of gravity is thus a central goal of fundamental physics. Observational clues arise from puzzles such as the "dark matter" and "dark energy" problems. These indicate an excess of attraction beyond what can be explained by the gravity of visible mass in galaxies (hence dark matter), and a net repulsion (dark energy) that drives the expansion rate of the universe to accelerate. It is conceivable that these diverse phenomena are related and may emerge from the quantum foundations of gravity. This work will develop and explore the observable consequences of Covariant Emergent Gravity, a theory that may provide a joint explanation for these as-yet ill-understood observations.This project aims to develop and test a new explanation for dark matter and dark energy. Verlinde has proposed the idea of gravity as an emergent phenomenon, but many of the consequences of this idea remain unexplored. A theoretical shortcoming is that it is not generally covariant. Recently, Hossenfelder addressed this problem by developing Covariant Emergent Gravity (CEG). CEG necessarily introduces terms beyond those already present in Emergent Gravity. The team proposes to develop this theory and to investigate whether CEG can be consistent with observations of galactic rotation curves. In particular, it will derive the formulas that govern the appropriate limit of the theory and numerically solve them to apply to real galaxies. This work must be carried out in the non-trivial, non-spherical case of the finite thickness cylindrical geometry appropriate to spiral galaxies. If the CEG hypothesis is incorrect, this work should readily falsify it. If there is some merit to it, it could point the way towards a fresh interpretation and potential resolution of the long-standing dark matter and dark energy problems, and provide insight into the nature of quantum gravity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.