Archived weekly pre-prints 23-04-10

Authors: Pietropaolo Frisoni
Subjects: General Relativity and Quantum Cosmology (gr-qc); Computational Physics (physics.comp-ph); Quantum Physics (quant-ph)
Arxiv link: https://arxiv.org/abs/2304.02691
Abstract We outline an algorithm to compute numerically the black-to-white hole transition amplitude, using the loop quantum gravity covariant formulation and the Lorentzian Engle-Pereira-Rovelli-Livine model. We apply the algorithm to calculate the crossing time of the transition in the deep quantum regime, comparing our result with previous analytical estimates of the same physical observable in the semiclassical limit. Furthermore, we show how to evaluate the crossing time analytically using an alternative approach with respect to the one currently present in the literature. This method requires much easier calculations and emphasizes that the crossing time does not depend on the extrinsic geometry of the transition.

There is no new related paper today

[2304.03055] - Axial perturbations of black holes in scalar-tensor gravity: near-horizon behaviour - Karim Noui, Hugo Roussille, David Langlois
[2304.03263] - Regular hairy black holes through Minkowski deformation - Jorge Ovalle, Roberto Casadio, Andrea Giusti
[2304.02668] - Coupling Fields to 3D Quantum Gravity via Chern-Simons Theory - Alejandra Castro, Ioana Coman, Jackson R. Fliss, Claire Zukowski
[2304.02673] - Approximate observables from non-isometric maps: de Sitter tensor networks with overlapping qubits - Chunjun Cao, Wissam Chemissany, Alexander Jahn, Zoltán Zimborás
[2304.03224] - On the renormalization group fixed point of the two-dimensional Ising model at criticality - Tobias J. Osborne, Alexander Stottmeister

There is no new related paper today

There is no new related paper today

[2304.01995] - Synge’s World function and the quantum spacetime - Dawood Kothawala
[2304.01292] - Holographic Quantum Gravity and Horizon Instability - Vaibhav Kalvakota
[2304.01414] - Maxwell’s Demon for Emergent Page Curve and Split Property - Yang An
[2304.01550] - Non-invertible symmetries and boundaries in four dimensions - Masataka Koide, Yuta Nagoya, Satoshi Yamaguchi
[2304.01936] - Shooting null geodesics into holographic spacetimes - Shunichiro Kinoshita, Keiju Murata, Daichi Takeda

Authors: Emanuele Alesci, Ilkka Mäkinen, Jinsong Yang
Subjects: General Relativity and Quantum Cosmology (gr-qc)
Arxiv link: https://arxiv.org/abs/2304.00268
Abstract Graphical techniques provide a very useful practical device for calculations involving the so-called spin network states, which encode the quantum degrees of freedom of spatial geometry in loop quantum gravity. Graphical calculus of SU(2), which has been originally introduced in the literature in order to deal with calculations arising from the coupling of angular momenta in quantum mechanics, can be used as a simple but powerful method for computing the action of various physically interesting operators in the spin network representation. Compared with conventional manipulation of algebraic expressions, calculations in the graphical approach are typically more convenient, concise and visually transparent. The goal of this chapter is to provide an accessible introduction to graphical methods in SU(2) recoupling theory and a brief description of their use as a tool for practical calculations in loop quantum gravity. We introduce the basics of the graphical formalism, and establish the representation of the elementary states and operators of loop quantum gravity in graphical form. Several example calculations are given to illustrate the use of the graphical techniques, including a computation of the matrix elements of a Hamiltonian constraint operator in the spin network basis.

Authors: Ilkka Mäkinen
Subjects: General Relativity and Quantum Cosmology (gr-qc)
Arxiv link: https://arxiv.org/abs/2304.00271
Abstract We introduce a new operator representing the three-dimensional scalar curvature in loop quantum gravity. The operator is constructed by writing the Ricci scalar classically as a function of the Ashtekar variables and regularizing the resulting expression on a cubical spin network graph. While our construction does not apply to the entire Hilbert space of loop quantum gravity, the proposed operator can be applied to concrete calculations in various approaches which are derived from the framework of full loop quantum gravity using states defined on cubical graphs.

There is no new related paper today

[2304.00088] - Synge’s world function applied to causal diamonds and causal sets - Arad Nasiri
[2304.00183] - Investigating the Connection between Generalized Uncertainty Principle and Asymptotically Safe Gravity in Black Hole Signatures through Shadow and Quasinormal Modes - Gaetano Lambiase, Reggie C. Pantig, Dhruba Jyoti Gogoi, Ali Övgün
[2304.00421] - Signatures of discretization in quantum black hole spectra - Joshua Foo, Robert B. Mann, Magdalena Zych
[2304.00940] - On the microstructure of higher-dimensional Reissner-Nordström black holes in quantum regime - Syed Masood A. S. Bukhari, Behnam Pourhassan, Houcine Aounallah, Mahdi Atashi, Li-Gang Wang
[2304.01154] - The neutrino pair annihilation ($ν+\barν\longrightarrow e^{-}+e^{+}$)around a Schwarzschild black hole in asymptotic safety - Yuxuan Shi, Hongbo Cheng
[2304.00166] - Thermal quantum gravity in a general background gauge - F. T. Brandt, J. Frenkel, D. G. C. McKeon, G. S. S. Sakoda
[2304.00982] - Eternal black holes and quantum temporal correlations - Ovidiu Racorean

Authors: Thomas Thiemann, Kristina Giesel
Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
Arxiv link: https://arxiv.org/abs/2303.18172
Abstract This chapter focuses on the status of the implementation of the dynamics in the canonical version of Loop Quantum Gravity (LQG). Concretely this means to provide a mathematical meaning of the quantum Einstein equations, sometimes called Wheeler-DeWitt equations, to give a physical interpretation and Hilbert space structure to its solutions and to construct a representation of the algebra of observables including a physical Hamiltonian. This is a structural overview intentionally skipping technical details.

There is no new related paper today

[2303.17640] - Quantum entanglement of masses with non-local gravitational interaction - Ulrich K. Beckering Vinckers, Álvaro de la Cruz-Dombriz, Anupam Mazumdar
[2303.17623] - Non-supersymmetric heterotic branes - Justin Kaidi, Kantaro Ohmori, Yuji Tachikawa, Kazuya Yonekura
[2303.17635] - Beyond AdS$_2$/dCFT$_1$: Insertions in Two Wilson Loops - Diego H. Correa, Alberto Faraggi, Wolfgang Mück, Leopoldo A. Pando Zayas, Guillermo A. Silva