English
Related papers

Related papers: The two-vertex model of loop quantum gravity: anis…

200 papers

We study the low energy states of finite spin chains with isotropic (Heisenberg) and anisotropic (XY and Ising-like) exchange interaction with uniform and non-uniform coupling constants. We show that for an odd number of sites a spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Florian Meier , Jeremy Levy , Daniel Loss

In this paper, we develop two anisotropic solutions for static self-gravitating spherical structure in the presence of electromagnetic field through gravitational decoupling approach in $f(G,T)$ theory, where $G$ and $T$ denote the…

General Relativity and Quantum Cosmology · Physics 2022-11-04 M. Sharif , Komal Hassan

Over the last two years, the canonical approach to quantum gravity based on connections and triads has been put on a firm mathematical footing through the development and application of a new functional calculus on the space of gauge…

High Energy Physics - Theory · Physics 2015-06-26 Abhay Ashtekar

This article sheds new light on the problem of cosmological reduction in Loop Quantum Gravity. We critically analyze Quantum Reduced Loop Gravity -- an attempt to extract the cosmological sector of the full theory. We reconsider the…

General Relativity and Quantum Cosmology · Physics 2021-01-12 Jakub Bilski , Antonino Marciano

We describe the quantum flat universe in QRLG in terms of states based at cuboidal graphs with six-valent nodes. We investigate the action of the scalar constraint operator at each node and we construct proper semiclassical states. This…

General Relativity and Quantum Cosmology · Physics 2015-11-04 Emanuele Alesci , Francesco Cianfrani

In the framework of Loop Quantum Cosmology, inhomogeneous models are usually quantized by means of a hybrid approach that combines loop quantization techniques with standard quantum field theory methods. This approach is based on a…

General Relativity and Quantum Cosmology · Physics 2016-08-23 B. Elizaga Navascués , M. Martín-Benito , G. A. Mena Marugán

We generalize the scalar tensor bigravity models to the non-minimal kinetic coupling scalar tensor bigravity models with two scalar fields whose kinetic terms are non-minimally coupled to two Einstein tensors constructed by two metrics. We…

General Relativity and Quantum Cosmology · Physics 2015-08-06 F. Darabi , M. Mousavi

We study the number of propagating degrees of freedom, at non-linear order, in torsion gravity theories, a class of modified theories of gravity that include a propagating torsion in addition to the metric. We focus on a three-parameter…

General Relativity and Quantum Cosmology · Physics 2025-01-23 Thibault Damour , Tamanna Jain

We perform the scattering analysis of the evolution operator of quantum walks with an anisotropic coin, and we prove a weak limit theorem for their asymptotic velocity. The quantum walks that we consider include one-defect models, two-phase…

Mathematical Physics · Physics 2018-06-13 S. Richard , A. Suzuki , R. Tiedra de Aldecoa

The discrete picture of geometry arising from the loop representation of quantum gravity can be extended by a quantum deformation. The operators for area and volume defined in the q-deformation of the theory are partly diagonalized. The…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Roumen Borissov , Seth Major , Lee Smolin

The use of techniques from loop quantum gravity for cosmological models may solve some difficult problems in quantum cosmology. The solutions under a number of circumstances have been well studied. We will analyse the behaviour of solutions…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Daniel Green , William G. Unruh

We consider the quantization of space-times which can possess different topologies within a symmetry reduced version of Wheeler-DeWitt theory. The quantum states are defined from a natural decomposition as an outer-product of a topological…

General Relativity and Quantum Cosmology · Physics 2014-04-17 Johan Brannlund , Andrew DeBenedictis , Alison Lauman

We investigate the cosmological applications of a bi-scalar modified gravity that exhibits partial conformal invariance, which could become full conformal invariance in the absence of the usual Einstein-Hilbert term and introducing…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Emmanuel N. Saridakis , Minas Tsoukalas

We give a standard introduction to loop quantum gravity, from the ADM variables to spin network states. We include a discussion on quantum geometry on a fixed graph and its relation to a discrete approximation of general relativity.

General Relativity and Quantum Cosmology · Physics 2010-09-21 Pietro Doná , Simone Speziale

We derive the most general homogeneous and isotropic teleparallel geometries, defined by a metric and a flat, affine connection. We find that there are five branches of connection solutions, which are connected via several limits, and can…

General Relativity and Quantum Cosmology · Physics 2023-04-25 Lavinia Heisenberg , Manuel Hohmann , Simon Kuhn

We describe the basic assumptions and key results of loop quantum gravity, which is a background independent approach to quantum gravity. The emphasis is on the basic physical principles and how one deduces predictions from them, at a level…

High Energy Physics - Theory · Physics 2017-08-23 Lee Smolin

We study the quantum evolution of a two-spin system described by the isotropic Heisenberg Hamiltonian in the external magnetic field. It is shown that this evolution happens on a two-parametric closed manifold. The Fubini-Study metric of…

Quantum Physics · Physics 2016-01-20 A. R. Kuzmak , V. M. Tkachuk

Measuring bipartite fluctuations of a conserved charge, such as the particle number, is a powerful approach to understanding quantum systems. When the measured region has sharp corners, the bipartite fluctuation receives an additional…

Mesoscale and Nanoscale Physics · Physics 2025-01-14 Pok Man Tam , Jonah Herzog-Arbeitman , Jiabin Yu

In this article, we investigate the quantum circuit complexity and entanglement entropy in the recently studied black hole gas framework using the two-mode squeezed states formalism written in arbitrary dimensional spatially flat…

High Energy Physics - Theory · Physics 2021-09-03 Kiran Adhikari , Sayantan Choudhury , Satyaki Chowdhury , K. Shirish , Abinash Swain

Recent results in the construction of anomaly-free models of loop quantum gravity have shown obstacles when local physical degrees of freedom are present. Here, a set of no-go properties is derived in polarized Gowdy models, raising the…

General Relativity and Quantum Cosmology · Physics 2015-09-09 Martin Bojowald , Suddhasattwa Brahma