English
Related papers

Related papers: On Spinfoam Models in Large Spin Regime

200 papers

We propose an explicit spin-foam amplitude for Lorentzian gravity in three dimensions, allowing for both space- and time-like boundaries. The model is based on two main requirements: that it should be structurally similar to its well-known…

General Relativity and Quantum Cosmology · Physics 2024-09-04 José Diogo Simão

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 examine the four dimensional path integral for Euclidean quantum gravity in the context of the EPRL-FK spin foam model. The state sum is restricted to certain symmetric configurations which resembles the geometry of a flat homogeneous…

General Relativity and Quantum Cosmology · Physics 2017-10-25 Benjamin Bahr , Sebastian Kloser , Giovanni Rabuffo

The large $j$ asymptotic behavior of $4$-dimensional spin foam amplitude is investigated for the extended spin foam model (Conrady-Hnybida extension) on a simplicial complex. We study the most general situation in which timelike tetrahedra…

General Relativity and Quantum Cosmology · Physics 2019-05-01 Hongguang Liu , Muxin Han

A review of the present state of investigations of the pseudospin-electron model (PEM), which is used in the theory of strongly correlated electron systems, is given. The model is used to describe the systems with the locally anharmonic…

Strongly Correlated Electrons · Physics 2016-11-23 Ihor Stasyuk

Gravitational waves from spin-precessing binaries exhibit equatorial asymmetries absent in non-precessing systems, leading to net linear momentum emission and contributing to the remnant's recoil. This effect, recently incorporated into…

General Relativity and Quantum Cosmology · Physics 2026-03-12 Héctor Estellés , Alessandra Buonanno , Raffi Enficiaud , Cheng Foo , Lorenzo Pompili

Spin foam models, an approach to defining the dynamics of loop quantum gravity, make use of the Plebanski formulation of gravity, in which gravity is recovered from a topological field theory via certain constraints called simplicity…

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

We study the quantum group deformation of the Lorentzian EPRL spin-foam model. The construction uses the harmonic analysis on the quantum Lorentz group. We show that the quantum group spin-foam model so defined is free of the infra-red…

General Relativity and Quantum Cosmology · Physics 2011-10-25 Muxin Han

We study spin-1/2 fermions in spin dependent potentials under the \emph{spin model approximation}, in which interatomic collisions that change the total occupation of single-particle modes are ignored. The spin model approximation maps the…

Quantum Gases · Physics 2020-09-02 Michael L. Wall

It was recently noted that the on-shell Einstein-Hilbert action with York-Gibbons-Hawking boundary term has an imaginary part, proportional to the area of the codimension-2 surfaces on which the boundary normal becomes null. We discuss the…

General Relativity and Quantum Cosmology · Physics 2013-09-13 Norbert Bodendorfer , Yasha Neiman

We calculate the most divergent contribution to the non-degenerate sector of the self-energy (or "melonic") graph in the context of the Lorentzian EPRL-FK Spin Foam model of Quantum Gravity. We find that such a contribution is…

General Relativity and Quantum Cosmology · Physics 2013-07-16 Aldo Riello

The relativistic precession model (RPM) is widely-considered as a benchmark framework to interpret quasi-periodic oscillations (QPOs), albeit several observational inconsistencies suggest that the model remains incomplete. The RPM ensures…

General Relativity and Quantum Cosmology · Physics 2025-12-16 Gabriele Bianchini , Orlando Luongo , Marco Muccino

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. Our result follows from the simultaneous…

General Relativity and Quantum Cosmology · Physics 2024-02-27 Pietro Dona , Francesco Gozzini , Alessandro Nicotra

We systematically test a quasi-classical spin model of a large spin-lattice in energy space, with a tunable, reversible Hamiltonian and effective long-range interactions. The system is simulated by a weakly interacting Fermi gas undergoing…

Quantum Gases · Physics 2023-12-04 J. Huang , Camen A. Royse , I. Arakelyan , J. E. Thomas

The behaviour of resonances in the spin-orbit coupling in Celestial Mechanics is investigated. We introduce a Hamiltonian nearly-integrable model describing an approximation of the spin-orbit interaction. A parametric representation of…

chao-dyn · Physics 2007-05-23 Alessandra Celletti , Luigi Chierchia

Using the coherent state techniques developed for the analysis of the EPRL model we give the asymptotic formula for the Ponzano-Regge model amplitude for non-tardis triangulations of handlebodies in the limit of large boundary spins. The…

General Relativity and Quantum Cosmology · Physics 2012-01-23 R. Dowdall , 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

We study the semiclassical limit of a class of invariant tensors for infinite-dimensional unitary representations of $\mathrm{SL}(2,\mathbb{C})$ of the principal series, corresponding to generalized Clebsch-Gordan coefficients with $n\geq3$…

General Relativity and Quantum Cosmology · Physics 2024-02-27 Pietro Dona , Marco Fanizza , Pierre Martin-Dussaud , Simone Speziale

We study a model of N-component complex fermions with a kinetic term that is second order in derivatives. This symplectic fermion model has an Sp(2N) symmetry, which for any N contains an SO(3) subgroup that can be identified with…

High Energy Physics - Theory · Physics 2009-04-17 André LeClair , Matthias Neubert

This work is dedicated to the study of both large-$N$ and perturbative quantum behaviors of Lifshitz nonlinear sigma models with dynamical critical exponent $z=2$ in 2+1 dimensions. We discuss renormalization and renormalization group…

High Energy Physics - Theory · Physics 2016-07-01 Pedro R. S. Gomes , M. Gomes