Functional Renormalization Group Methods in Quantum Gravity

点击翻译按钮获取中文摘要

One of the major challenges in theoretical high energy physics is the construction of a fundamental theory of gravity valid at all distance scales. While such a description is yet unknown, it is expected to provide answers to central questions such as the tiny value of the cosmological constant or the origin of dark matter. This proposal will spearhead the exploration of a promising candidate theory for Quantum Gravity, Weinberg’s asymptotic safety scenario. Here the key idea is that gravity is a consistent and predictive quantum theory at the nonperturbative level. The primary tools for investigating this scenario analytically are functional renormalization group equations, which provide an important window on the non-perturbative properties of the theory. So far these have yielded substantial evidence for asymptotic safety without yet being conclusive. Thus our proposal will develop new techniques for studying the non-perturbative renormalization group flow of pure gravity, gravity-matter, and supergravity theories. These will be used to implement several acid tests for asymptotic safety and study its phenomenological consequences for the physics of the early universe, black holes, cosmology and supersymmetry. Moreover, connecting hitherto unrelated candidate theories of Quantum Gravity, our work will boost the understanding of several open conceptual points in this research area.