Chiral Fermions and Quantum Gravity

手性费米子和量子引力

• 批准号: 266047446
• 负责人: Professor Dr. Holger Gies
• 金额: --
• 依托单位: Theoretisch-Physikalisches Institut
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/266047446?language=en
• 关键词: Chiral; Fermions; Quantum; Gravity

The challenge of developing a convincing and consistent theory of quantum gravity is hampered perhaps less by theoretical problems than by the lack of clear observational unambiguous data. The present project suggests to use the well-known observation that the fundamental matter constituents are given by chiral fermions as a probe for possible quantum gravity scenarios.Chiral symmetry is an essential ingredient in elementary particle physics. It ensures that fermions with comparatively small masses can exist in Nature. On the other hand, chirality can be spontaneously broken by quantum fluctuations, as it is the case in the electroweak and strong interactions. As gravity are expected to become relevant near the Planck scale, gravity fluctuations must not break the chiral symmetry of the chiral fermions. Otherwise the observation of light fermions in our universe would not be compatible with such gravity interactions.The main objective of this proposal is to interconnect the observed existence of light (chiral) fermions with generic quantum gravity scenarios. For this, the established theoretical framework of quantum field theory will be used with gravity being treated either as an effective field theory or an asymptotically safe fundamental quantum theory. With this tool the project can address the following questions: Can gravitationally induced chiral symmetry breaking (gravitational catalysis) and fermion mass generation be active in the high-energy quantum gravity regime? Does chiral symmetry breaking through gravitational catalysis put constraints on or even rule out some quantum-gravity scenarios? In turn, is the number of fermion fields (e.g., flavors) constrained through gravitational interactions? Is the existence of non-chiral fermions compatible with specific quantum gravity scenarios? Answers to these questions may provide unprecedented but stringent guidelines to the development to a quantum gravity theory that is not only mathematically convincing but also compatible with physical observations.

发展一个令人信服的和一致的量子引力理论的挑战，可能不是因为理论问题，而是因为缺乏明确的观测数据。手征对称性是基本粒子物理学中的一个重要组成部分，手征费米子给出了基本物质的组成，本项目建议利用手征费米子给出的基本物质组成作为可能的量子引力方案的探针。它确保了质量相对较小的费米子可以存在于自然界中。 另一方面，手征性可以被量子涨落自发打破，就像在电弱相互作用和强相互作用中一样。由于引力在普朗克尺度附近变得相关，引力涨落不能破坏手征费米子的手征对称性。否则，在我们的宇宙中观测到的轻费米子将与这种引力相互作用不相容。本提案的主要目标是将观测到的轻（手征）费米子的存在与一般的量子引力情景联系起来。为此，将使用量子场论的已建立的理论框架，并将引力视为有效场论或渐近安全的基本量子理论。有了这个工具，该项目可以解决以下问题：引力诱导的手征对称性破缺（引力催化）和费米子质量产生在高能量子引力体系中是否活跃？手征对称性通过引力催化的破缺是否会限制甚至排除某些量子引力的可能性？ 反过来，是费米子场的数量（例如，通过引力相互作用约束？非手征费米子的存在与特定的量子引力情形相容吗？这些问题的答案可能会为量子引力理论的发展提供前所未有的但严格的指导方针，这种理论不仅在数学上令人信服，而且与物理观测兼容。

项目成果

Gravitational Two-Loop Counterterm Is Asymptotically Safe.

• DOI: 10.1103/physrevlett.116.211302
• 发表时间: 2016-01
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: H. Gies;B. Knorr;Stefan Lippoldt;F. Saueressig

Generalized parametrization dependence in quantum gravity

量子引力中的广义参数化依赖性

• DOI: 10.1103/physrevd.92.084020
• 发表时间: 2015
• 期刊: Physical Review D
• 影响因子: 5
• 作者: H. Gies;B. Knorr;S. Lippoldt
• 通讯作者: S. Lippoldt

Renormalization group flow of the Higgs potential

• DOI: 10.1098/rsta.2017.0120
• 发表时间: 2017-08
• 期刊: Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
• 作者: H. Gies;R. Sondenheimer

Curvature bound from gravitational catalysis

• DOI: 10.1103/physrevd.97.085017
• 发表时间: 2018-02
• 期刊: Physical Review D
• 影响因子: 5
• 作者: H. Gies;Riccardo Martini