2011/11/04 by Astrid Eichhorn, Eichhorn, Astrid
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Deconfinement #FOS: Physical sciences #Fermion #Gauge group #Gauge theory #General Relativity and Quantum Cosmology (gr-qc) #Group field theory #High Energy Physics - Theory (hep-th) #Hořava–Lifshitz gravity #Loop quantum gravity #Mathematical physics #Non-perturbative #Noncommutative and Quantum Gravity Theories #Phase transition #Physics #Quantum #Quantum dynamics #Quantum gravity #Quantum mechanics #Relativity and Gravitational Theory #Semiclassical gravity #Spin foam #Theoretical physics #Yang–Mills existence and mass gap #Yang–Mills theory #gr-qc #hep-th
paper · pdf · doi:10.48550/arxiv.1111.1237
published in arXiv (Cornell University) (Cornell University) · PhD thesis, 152 pages
arxiv created 2011/11/04 · openalex publication_date 2011/11/04 · arxiv updated 2011/11/08 · openalex created_date 2020/07/16 · openalex updated_date 2026/07/28
In this thesis we investigate two different sets of physics questions, aiming\nat a better understanding of the low-energy behaviour of Yang-Mills theories,\nand the properties connected to confinement, in a first part. In a second part,\nwe consider asymptotically safe quantum gravity, which is a proposal for a UV\ncompletion of gravity, based on the existence of an interacting UV fixed point\nin the Renormalisation Group flow. Both theories are characterised by\nnon-perturbative behaviour, the first in the IR, the second in the UV, thus we\napply a functional Renormalisation Group equation which is valid beyond the\nperturbative regime. We investigate the ground state of SU(3) Yang-Mills\ntheory, finding the formation of a gluon condensate, which we connect to a\nmodel for quark confinement. We further investigate the deconfinement phase\ntransition at finite temperature for several gauge groups and shed light on the\nquestion what determines the order of the phase transition. Within quantum\ngravity, we examine the properties of the Faddeev-Popov ghost sector in a\nnon-perturbative regime, thus extending truncations of Renormalisation Group\nflows into a new set of directions in theory space. Finally we establish a\nconnection of quantum gravity to observations of matter, by coupling fermions\nto gravity. Here we use the existence of light fermions - an observationally\nwell-established fact in our universe - to impose constraints on quantum\ntheories of gravity.\n