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Related papers: A new spinfoam vertex for quantum gravity

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A dual formulation of group field theories, obtained by a Fourier transform mapping functions on a group to functions on its Lie algebra, has been proposed recently. In the case of the Ooguri model for SO(4) BF theory, the variables of the…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Aristide Baratin , Daniele Oriti

Within the twistorial parametrization of Loop Quantum Gravity we investigate the consequences of choosing a spacelike normal vector in the linear simplicity constraints. The amplitudes for the $SU(2)$ boundary states of Loop Quantum…

General Relativity and Quantum Cosmology · Physics 2017-01-13 Julian Rennert

This paper focuses on the semiclassical behavior of the spinfoam quantum gravity in 4 dimensions. There has been long-standing confusion, known as the flatness problem, about whether the curved geometry exists in the semiclassical regime of…

General Relativity and Quantum Cosmology · Physics 2022-08-12 Muxin Han , Zichang Huang , Hongguang Liu , Dongxue Qu

An important challenge in loop quantum gravity is to find semiclassical states - states that are as close to classical as quantum theory allows. This is difficult because the states in the Hilbert space used in LQG are excitations over a…

General Relativity and Quantum Cosmology · Physics 2020-06-01 Hanno Sahlmann , Robert Seeger

Coherent states on the quantum group $SU_q(2)$ are defined by using harmonic analysis and representation theory of the algebra of functions on the quantum group. Semiclassical limit $q\rightarrow 1$ is discussed and the crucial role of…

High Energy Physics - Theory · Physics 2010-11-01 I. Ya. Aref'eva , R. Parthasarathy , K. S. Viswanathan , I. V. Volovich

We derive the the Barrett-Crane spin foam model for Euclidean 4 dimensional quantum gravity from a discretized BF theory, imposing the constraints that reduce it to gravity at the quantum level. We obtain in this way a precise prescription…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Daniele Oriti , Ruth M. Williams

We investigate the quantum geometry of $2d$ surface $S$ bounding the Cauchy slices of 4d gravitational system. We investigate in detail and for the first time the symplectic current that naturally arises boundary term in the first order…

General Relativity and Quantum Cosmology · Physics 2015-07-10 Laurent Freidel , Alejandro Perez

A spinfoam model of 3D gravity non-minimally coupled with a scalar field is studied. By discretization of the scalar field, the model is worked out precisely in a purely combinational way. It is shown that the quantum physics of the scalar…

General Relativity and Quantum Cosmology · Physics 2010-04-30 Peng Xu , Yongge Ma

In a recent work, a dual formulation of group field theories as non-commutative quantum field theories has been proposed, providing an exact duality between spin foam models and non-commutative simplicial path integrals for constrained BF…

High Energy Physics - Theory · Physics 2013-05-30 Aristide Baratin , Daniele Oriti

In this article we give a systematic definition of the recently introduced spin foam models for four dimensional quantum gravity reviewing the main results on their semiclassical limit on fixed discretizations.

General Relativity and Quantum Cosmology · Physics 2012-05-07 Alejandro Perez

The evolution of quantum states influenced by semiclassical gravity is distinct from that in quantum gravity theory due to the presence of a state-dependent gravitational potential. This state-dependent potential introduces nonlinearity…

Quantum Physics · Physics 2025-03-14 Yubao Liu , Wenjie Zhong , Yanbei Chen , Yiqiu Ma

Nonclassicality of quantum states is expressed in many shades, the most stringent of them being a new standard introduced recently in [Phys. Rev. A 89, 062110 (2014)]. This is accomplished by expanding the notion of local hidden variables…

Quantum Physics · Physics 2017-03-08 S. Adhikary , I. Panda , V. Ravishankar

A finite-dimensional pseudo-unitary framework is set up for describing the dynamics of free elementary particles in a purely relativistic quantum mechanical way. States of any individual particles or antiparticles are defined as suitably…

Mathematical Physics · Physics 2015-02-03 Jorge G. Cardoso

The mathematical apparatus of quantum--mechanical angular momentum (re)coupling, developed originally to describe spectroscopic phenomena in atomic, molecular, optical and nuclear physics, is embedded in modern algebraic settings which…

Quantum Physics · Physics 2010-04-14 V. Aquilanti , A. C. P. Bitencourt , C. da S. Ferreira , A. Marzuoli , M. Ragni

We construct normalizable, semi-classical states for the previously proposed model of quantum gravity which is formulated as a spectral triple over holonomy loops. The semi-classical limit of the spectral triple gives the Dirac Hamiltonian…

High Energy Physics - Theory · Physics 2011-03-02 Johannes Aastrup , Jesper M. Grimstrup , Mario Paschke , Ryszard Nest

Spin Foam Models (SFMs) are covariant formulations of Loop Quantum Gravity (LQG) in 4 dimensions. This work studies the perturbations of SFMs on a flat background. It demonstrates for the first time that smooth curved spacetime geometries…

General Relativity and Quantum Cosmology · Physics 2019-08-07 Muxin Han , Zichang Huang , Antonia Zipfel

We investigate a formulation of continuum 4d gravity in terms of a constrained BF theory, in the spirit of the Plebanski formulation, but involving only linear constraints, of the type used recently in the spin foam approach to quantum…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Steffen Gielen , Daniele Oriti

In this thesis we study the flat model, the main buidling block for the spinfoam approach to quantum gravity, with an emphasis on its divergences. Besides a personal introduction to the problem of quantum gravity, the manuscript consists in…

General Relativity and Quantum Cosmology · Physics 2012-01-25 Matteo Smerlak

Spin Foam and Loop approaches to Quantum Gravity reformulate Einstein's theory of relativity in terms of connection variables. The metric properties are encoded in face bivectors/conjugate fluxes that are required to satisfy certain…

General Relativity and Quantum Cosmology · Physics 2019-05-17 Vadim Belov

The Hamiltoinian analysis of the vector-tensor theory of gravity is performed. The resulting geometrical dynamics is reformulated into the connection dynamics, with the real SU(2)-connection serving as one of the configuration variables.…

General Relativity and Quantum Cosmology · Physics 2026-02-24 Shengzhi Li , Yongge Ma