Results 41 to 50 of about 1,109,861 (332)
Toward matter dynamics in spin foam quantum gravity [PDF]
Physical Review D, 2022 Any approach to pure quantum gravity must eventually face the question of coupling quantum matter to the theory. In the past, several ways of coupling matter to spin foam quantum gravity have been proposed, but the dynamics of the coupled matter-gravity ...
Masooma Ali, S. Steinhaus
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Geometry from local flatness in Lorentzian spin foam theories [PDF]
Physical Review D, 2022 Local flatness is a property shared by all the spin foam models. It ensures that the theory's fundamental building blocks are flat by requiring locally trivial parallel transport.
P. Donà
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Saddle-point finder and its application to the spin foam model [PDF]
Physical Review D, 2022 We introduce a saddle-point finder that can find the complex saddle points for any analytically continued action. We showcase our saddle-point finder by two examples in the EPRL spin foam model: the single vertex case and the case of triangulation ...
Zichang Huang, Shan-Chi Huang, Yidun Wan
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Relating spin-foam to canonical loop quantum gravity by graphical calculus [PDF]
Physical Review D, 2021 The graphical calculus method is generalized to study the relation between covariant and canonical dynamics of loop quantum gravity. On one hand, a graphical derivation of the partition function of the generalized Euclidean Engle-Pereira-Rovelli-Livine ...
Jinsong Yang, Cong Zhang, Yongge Ma
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Wick rotation for spin foam quantum gravity [PDF]
Physical Review D, 2021 We show that the Euclidean and Lorentzian EPRL vertex amplitudes of covariant Loop Quantum Gravity are related through a ``Wick rotation'' of the real Immirzi parameter to purely imaginary values.
P. Donà, F. Gozzini, Alessandro Nicotra
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Spin foams without spins [PDF]
Classical and Quantum Gravity, 2016 21 pages, 2 ...
Hnybida, J.T., Hnybida, J.T.
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International Journal of Modern Physics D, 2012 The central object of this paper is a holonomy formulation for spin foams. Within this new representation, we analyze three general requirements: locality, composition law and cylindrical consistency. In particular, cylindrical consistency is shown to fix the arbitrary normalization of the vertex amplitude in the case of Euclidean signature.
Magliaro, Elena, Perini, Claudio
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Energies, 2021 The effects of doping manganese ions into a cerium oxide lattice for a thermochemical two-step water-splitting cycle to produce oxygen and hydrogen and new synthesis methods were experimentally investigated.
Hyun-Seok Cho +4 more
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Effective Spin Foam Models for Four-Dimensional Quantum Gravity. [PDF]
Physical Review Letters, 2020 A number of approaches to four-dimensional quantum gravity, such as loop quantum gravity and holography, situate areas as their fundamental variables. However, this choice of kinematics can easily lead to gravitational dynamics peaked on flat spacetimes.
Seth K. Asante +2 more
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Spin foams with timelike surfaces [PDF]
Classical and Quantum Gravity, 2010 22 pages, no figures; v2: remarks on operator formalism added in discussion; correction: the spin 1/2 irrep of the discrete series does not appear in the Plancherel ...
Florian Conrady
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