2017/10/31 by Markus B. Fröb · 43 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Coupling constant #Gauge theory #Geometry #Gravitation #Graviton #Introduction to gauge theory #Invariant (physics) #Mathematical physics #Noncommutative and Quantum Gravity Theories #Observable #Particle physics #Physics #Quantum mechanics #Scalar (mathematics) #Scalar field #Theoretical physics #gr-qc #hep-th
paper · pdf · doi:10.1088/1361-6382/aaa74c
published in Classical and Quantum Gravity 35(5), 055006 (IOP Publishing) · 34 pages, 1 figure, matches published version
openalex publication_date 2018/01/12 · arxiv created 2018/02/01 · arxiv updated 2018/02/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract A recent proposal for gauge-invariant observables in inflation (Brunetti et al 2016 J. High Energy Phys . JHEP08(2016)032) is examined. We give a generalisation of their construction to general background spacetimes. In flat space, we calculate one-loop graviton corrections to a scalar two-point function in a general gauge for the graviton. We explicitely show how the gauge-dependent terms cancel between the usual self-energy contributions and the additional corrections inherent in these observables. The one-loop corrections have the expected functional form, contrary to another recently studied proposal for gauge-invariant observables (Fröb 2018 Class. Quantum Grav . 35 035005) where this is not the case. Furthermore, we determine the one-loop graviton corrections to the four-point coupling of the gauge-invariant scalar field, and the corresponding running of the coupling constant induced by graviton loops. Interestingly, the β function is negative for all values of the non-minimal coupling of the scalar field to curvature.