Developing Quantum Gravity via novel Functional Renormalization Group Techniques

• Applicant: Dr. Maximilian Becker
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 493330310

The development of a quantum description of nature incorporating gravity is one of the most fascinating open questions in modern-day physics. Currently, there are various promising paths towards a fundamental formulation of the gravitational interaction and spacetime geometry valid at all scales. Among these approaches, the Asymptotic Safety program is distinguished by its minimalistic perspectives onto the problem. It builds on Weinberg's conjecture that gravity constitutes a consistent, non-perturbatively renormalizable, quantum theory. My proposal builds on the strong evidence which has been collected in favor of this scenario, and addresses the key open questions in the field by, firstly, extending the Functional Renormalization Group methods which currently constitute the methodological backbone of the program and, secondly, advancing the construction of observables for quantum gravity. These developments will form the basis for developing the characterization of quantum spacetime and its connection to classical geometry, the explanation of the (black hole) entropy puzzle as well as for systematically improving the approximations which are used to investigate Asymptotic Safety today. In this way, my research project will provide the essential groundwork for the comparison of the various approaches towards quantum gravity as well as for the long-term goal of predicting quantum-gravitational effects in observational cosmology.During my PhD, supervised by Prof. Dr. Martin Reuter, I have worked on a wide range of conceptual questions related to Asymptotic Safety. This puts me in a unique position to successfully address the challenging research questions. The project will be carried out in the quantum gravity group (host scientist: Dr. Frank Saueressig) at the Radboud University Nijmegen. The group's expertise on a wide range of quantum gravity programs makes the host a distinguished environment for carrying out this research project.

• DFG Programme: WBP Fellowship
• International Connection: Netherlands
• Host: Professor Dr. Frank Saueressig