English
Related papers

Related papers: Studying the EPRL spinfoam self-energy

200 papers

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. We…

General Relativity and Quantum Cosmology · Physics 2024-02-27 Pietro Dona

The semiclassical limit of a 4-simplex amplitude for a spin foam quantum gravity model with an Immirzi parameter is studied. If the boundary state represents a non-degenerate 4-simplex geometry, the asymptotic formula contains the Regge…

General Relativity and Quantum Cosmology · Physics 2010-01-15 John W. Barrett , R. J. Dowdall , Winston J. Fairbairn , Henrique Gomes , Frank Hellmann

We review the basic steps in building the asymptotic analysis of the Euclidean sector of new spin foam models using coherent states, for Immirzi parameter less than one. We focus on conceptual issues and by so doing omit peripheral proofs…

General Relativity and Quantum Cosmology · Physics 2015-05-14 John W. Barrett , Richard J. Dowdall , Winston J. Fairbairn , Henrique Gomes , Frank Hellmann

In previous work, the Lorentzian proper vertex amplitude for a spin-foam model of quantum gravity was derived. In the present work, the asymptotics of this amplitude are studied in the semi-classical limit. The starting point of the…

General Relativity and Quantum Cosmology · Physics 2016-09-14 Jonathan Engle , Ilya Vilensky , Antonia Zipfel

We study the asymptotic properties of four-simplex amplitudes for various four-dimensional spin foam models. We investigate the semi-classical limit of the Ooguri, Euclidean and Lorentzian EPRL models using coherent states for the boundary…

General Relativity and Quantum Cosmology · Physics 2015-05-18 John W. Barrett , Richard J. Dowdall , Winston J. Fairbairn , Henrique Gomes , Frank Hellmann , Roberto Pereira

We present explicit expressions for the high-frequency asymptotic behavior of electron self-energy of general quantum impurity models, which may be useful for improving the convergence of dynamical mean-field calculations and for the…

Strongly Correlated Electrons · Physics 2011-08-16 Xin Wang , Hung The Dang , Andrew J. Millis

We study the semiclassical behavior of Lorentzian Engle-Pereira-Rovelli-Livine (EPRL) spinfoam model, by taking into account of the sum over spins in the large spin regime. The large spin parameter \lambda and small Barbero-Immirzi…

General Relativity and Quantum Cosmology · Physics 2013-09-09 Muxin Han

Utilizing the most recent experimental data, we reanalyze high energy \pbar p and pp data, using the asymptotic amplitude analysis, under the assumption that we have reached `asymptopia'. This analysis gives strong evidence for a $\log…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. M. Block , A. R. White , B. Margolis

A certain operator $\T=\int_{\SL}\dd g\, Y^{\dagger}gY$ can be found in various Lorentzian EPRL calculations. The properties of this operator has been studied here in large $j$ limit. The leading order of $\T$ is proportional to the…

General Relativity and Quantum Cosmology · Physics 2013-07-19 Jacek Puchta

As established in a prior work of the author, the linear simplicity constraints used in the construction of the so-called `new' spin-foam models mix three of the five sectors of Plebanski theory as well as two dynamical orientations, and…

General Relativity and Quantum Cosmology · Physics 2013-09-16 Jonathan Engle

We investigate the asymptotic behavior of the eigenvalues of the Laplacian with homogeneous Robin boundary conditions, when the (positive) Robin parameter is diverging. In this framework, since the convergence of the Robin eigenvalues to…

Analysis of PDEs · Mathematics 2025-07-15 Roberto Ognibene

We numerically estimate the divergence of several two-vertex diagrams that contribute to the radiative corrections for the Lorentzian EPRL spin foam propagator. We compute the amplitudes as functions of a homogeneous cutoff over the bulk…

General Relativity and Quantum Cosmology · Physics 2022-11-04 Pietro Donà , Pietropaolo Frisoni , Edward Wilson-Ewing

We numerically study the next-to-leading order corrections of the Lorentzian Engle-Pereira-Rovelli-Livine (EPRL) 4-simplex amplitude in the large-$j$ expansions. We perform large-$j$ expansions of Lorentzian EPRL 4-simplex amplitudes with…

General Relativity and Quantum Cosmology · Physics 2021-03-02 Muxin Han , Zichang Huang , Hongguang Liu , Dongxue Qu

We consider a general second-order elliptic differential operator on a domain with a cylindrical end. We impose Dirichlet boundary conditions on the boundary with the exception of a small set, where we impose Neumann boundary conditions.…

Spectral Theory · Mathematics 2017-10-06 André Froehly

In this note we obtain an asymptotic estimate for growth behavior of variational eigenvalues of the $p-$fractional eigenvalue problem on a smooth bounded domain with Dirichlet boundary condition.

Analysis of PDEs · Mathematics 2021-11-08 Ariel Salort , Eugenio Vecchi

The spectrum of the Dirichlet Laplacian on conical layers is analysed through two aspects: the infiniteness of the discrete eigenvalues and their expansions in the small aperture limit. On the one hand, we prove that, for any aperture, the…

Numerical Analysis · Mathematics 2017-11-23 Monique Dauge , Thomas Ourmières-Bonafos , Nicolas Raymond

The purpose of this paper is to explore the asymptotics of the eigenvalue spectrum of the Laplacian on 2 dimensional spaces of constant curvature, giving strong experimental evidence for a conjecture of the second author…

Analysis of PDEs · Mathematics 2018-09-25 Timothy Murray , Robert S. Strichartz

We compute transition amplitudes between two spin networks with dipole graphs, using the Lorentzian EPRL model with up to two (non-simplicial) vertices. We find power-law decreasing amplitudes in the large spin limit, decreasing faster as…

General Relativity and Quantum Cosmology · Physics 2018-04-11 Giorgio Sarno , Simone Speziale , Gabriele V. Stagno

We contemplate the pair of the purely imaginary delta-function potentials on a finite interval with Dirichlet boundary conditions. The two parameter model exhibits nicely the expected quantitative features of the unavoided level crossing…

Quantum Physics · Physics 2007-05-23 Vit Jakubsky , Miloslav Znojil

We study the semiclassical behavior of Lorentzian Engle-Pereira-Rovelli-Livine (EPRL) spinfoam model, by taking into account the sum over spins in the large spin regime. We also employ the method of stationary phase analysis with parameters…

General Relativity and Quantum Cosmology · Physics 2013-11-18 Muxin Han
‹ Prev 1 2 3 10 Next ›