Results 71 to 80 of about 1,109,861 (332)
Renormalization of symmetry restricted spin foam models with curvature in the asymptotic regime [PDF]
Physical Review D, 2018 We study the renormalization group flow of the Euclidean Engle-Pereira-Rovelli-Livine and Freidel-Krasnov (EPRL-FK) spin foam model in the large-$j$ limit. The vertex amplitude is deformed to include a cosmological constant term. The state sum is reduced
Benjamin Bahr +2 more
semanticscholar +1 more source
On knottings in the physical Hilbert space of LQG as given by the EPRL model [PDF]
, 2010 We consider the EPRL spin foam amplitude for arbitrary embedded two-complexes. Choosing a definition of the face- and edge amplitudes which lead to spin foam amplitudes invariant under trivial subdivisions, we investigate invariance properties of the ...
Barrett J +17 more
core +1 more source
, 2004 We discuss the notion of causality in Quantum Gravity in the context of sum-over-histories approaches, in the absence therefore of any background time parameter.
Oriti, Daniele
core +4 more sources
Spin Foams, Refinement Limit, and Renormalization
, 2023 This preprint is to appear as a chapter in "Handbook of Quantum Gravity" (Editors: C. Bambi, L. Modesto and I.L. Shapiro), Springer.
Asante, Seth K. +2 more
openaire +2 more sources
Infrared divergences in the EPRL-FK spin foam model [PDF]
Classical and quantum gravity, 2018 We provide an algorithm to estimate the divergence degree of the Lorentzian EPRL-FK spin foam amplitudes for arbitrary 2-complexes. We focus on the ‘self-energy’ and ‘vertex renormalization’ diagrams and find an upper bound estimate.
P. Donà
semanticscholar +1 more source
Emergence of spacetime in a restricted spin-foam model [PDF]
Physical Review D, 2018 The spectral dimension has proven to be a very informative observable to understand the properties of quantum geometries in approaches to quantum gravity. In loop quantum gravity and its spin foam description, it has not been possible so far to calculate
S. Steinhaus, Johannes Thurigen
semanticscholar +1 more source
Cosmological deformation of Lorentzian spin foam models [PDF]
Classical and Quantum Gravity, 2003 We study the quantum deformation of the Barrett-Crane Lorentzian spin foam model which is conjectured to be the discretization of Lorentzian Plebanski model with positive cosmological constant and includes therefore as a particular sector quantum gravity in de-Sitter space.
Roche, Philippe, Noui, K.
openaire +3 more sources
Hypercuboidal renormalization in spin foam quantum gravity [PDF]
, 2017 In this article we apply background-independent renormalization group methods to spin foam quantum gravity. It is aimed at extending and elucidating the analysis of a companion letter, in which the existence of a fixed point in the truncated RG flow for ...
Benjamin Bahr, S. Steinhaus
semanticscholar +1 more source
Loop quantization from a lattice gauge theory perspective [PDF]
, 2004 We present an interpretation of loop quantization in the framework of lattice gauge theory. Within this context the lack of appropriate notions of effective theories and renormalization group flow exhibit loop quantization as an incomplete framework ...
Zapata, José A.
core +1 more source
Spin foam models and the Duflo map [PDF]
Classical and quantum gravity, 2018 We give a general definition of spin foam models, and then of models of 4d quantum gravity based on constraining BF theory. We highlight the construction and quantization ambiguities entering model building, among which the choice of quantization map ...
M. Finocchiaro, D. Oriti
semanticscholar +1 more source