Results 51 to 60 of about 46,248 (301)

Recurrence relations for spin foam vertices [PDF]

Classical and Quantum Gravity, 2010
We study recurrence relations for various Wigner 3nj-symbols and the non-topological 10j-symbol. For the 6j-symbol and the 15j-symbols which correspond to basic amplitudes of 3d and 4d topological spin foam models, recurrence relations are obtained from the invariance under Pachner moves and can be interpreted as quantizations of the constraints of the
Simone Speziale, Etera R. Livine, Valentin Bonzom, Valentin Bonzom   +3 more
openaire   +6 more sources

An Overview of the Effectiveness of Bicycle Helmet Designs in Impact Testing

Frontiers in Bioengineering and Biotechnology, 2021
Cycling accidents are the leading cause of sports-related head injuries in the US. Conventional bicycle helmets typically consist of polycarbonate shell over Expanded Polystyrene (EPS) foam and are tested with drop tests to evaluate a helmet’s ability to
Javid Abderezaei, Fargol Rezayaraghi, Brigit Kain, Andrea Menichetti, Mehmet Kurt, Mehmet Kurt   +5 more
doaj   +1 more source

Spin Foam Vertex Amplitudes on Quantum Computer—Preliminary Results

Universe, 2019
Vertex amplitudes are elementary contributions to the transition amplitudes in the spin foam models of quantum gravity. The purpose of this article is to make the first step towards computing vertex amplitudes with the use of quantum algorithms.
Jakub Mielczarek
doaj   +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

Lorentzian Quantum Cosmology from Effective Spin Foams

Universe
Effective spin foams provide the most computationally efficient spin foam models yet and are therefore ideally suited for applications, e.g., to quantum cosmology.
Bianca Dittrich, José Padua-Argüelles
doaj   +1 more source

Asymptotics of 4d spin foam models [PDF]

General Relativity and Gravitation, 2010
10 pages, Proceedings for the 2nd Corfu summer school and workshop on quantum gravity and quantum geometry, talk given by Winston J ...
Frank Hellmann, John W. Barrett, Richard J. Dowdall, Henrique Gomes, Roberto Pereira, Winston J. Fairbairn, Winston J. Fairbairn   +6 more
openaire   +5 more sources

The Feynman propagator for quantum gravity: spin foams, proper time, orientation, causality and timeless-ordering

, 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

Towards a spin foam model description of black hole entropy

, 2008
We propose a way to describe the origin of black hole entropy in the spin foam models of quantum gravity. This stimulates a new way to study the relation of spin foam models and loop quantum gravity.Comment: 5 pages, 1 ...
Corichi A, Domagala M, Freidel L, J Manuel García-Islas, Kloster S, Manuel Garcia-Islas J, Tamaki T, Tanaka T Tamaki T   +7 more
core   +1 more source

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., Dittrich, Bianca, Steinhaus, Sebastian   +2 more
openaire   +2 more sources

Atomic Size Misfit for Electrocatalytic Small Molecule Activation

Advanced Functional Materials, EarlyView.
This review explores the application and mechanisms of atomic size misfit in catalysis for small molecule activation, focusing on how structural defects and electronic properties can effectively lower the energy barriers of chemical bonds in molecules like H2O, CO2, and N2.
Ping Hong, Changfan Xu, Huaping Zhao, Yong Lei   +3 more
wiley   +1 more source