English
Related papers

Related papers: Relational evolution of effectively interacting GF…

200 papers

We give a general procedure, in the group field theory (GFT) formalism for quantum gravity, for constructing states that describe macroscopic, spatially homogeneous universes. These states are close to coherent (condensate) states used in…

General Relativity and Quantum Cosmology · Physics 2014-06-06 Steffen Gielen , Daniele Oriti , Lorenzo Sindoni

We derive the interaction of fermions with a dynamical space-time based on the postulate that the description of physics should be independent of the reference frame, which means to require the form-invariance of the fermion action under…

General Relativity and Quantum Cosmology · Physics 2021-08-31 Jürgen Struckmeier , David Vasak

We discuss the relational strategy to solve the problem of time in quantum gravity and different ways in which it could be implemented, pointing out in particular the fundamentally new dimension that the problem takes in a quantum gravity…

General Relativity and Quantum Cosmology · Physics 2021-09-23 Luca Marchetti , Daniele Oriti

Isotropic models in loop quantum cosmology allow explicit calculations, thanks largely to a completely known volume spectrum, which is exploited in order to write down the evolution equation in a discrete internal time. Because of genuinely…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Martin Bojowald

We study the dynamics of perturbations representing deviations from perfect isotropy in the context of the emergent cosmology obtained from the group field theory formalism for quantum gravity. Working in the mean field approximation of the…

General Relativity and Quantum Cosmology · Physics 2017-12-12 Marco de Cesare , Daniele Oriti , Andreas G. A. Pithis , Mairi Sakellariadou

We develop a formalism to help calculate in quantum field theory the departures from the description of a system by classical field equations. We apply the formalism to a homogeneous condensate with attractive contact interactions and to a…

High Energy Physics - Phenomenology · Physics 2018-03-07 Sankha S. Chakrabarty , Seishi Enomoto , Yaqi Han , Pierre Sikivie , Elisa M. Todarello

We summarize the main ideas behind TGFT condensate cosmology and sketch the technical steps that bring from the fundamental theory to the effective cosmological dynamics. This framework is presented as an explicit illustration of (and…

General Relativity and Quantum Cosmology · Physics 2022-02-10 Daniele Oriti

A new set of field equations for a space-time dependent Newton's constant $G(x)$ and cosmological constant $\Lambda(x)$ in the presence of matter is presented. We prove that it represents the most general mathematically consistent,…

General Relativity and Quantum Cosmology · Physics 2021-05-19 Alfio Bonanno , Georgios Kofinas , Vasilios Zarikas

In a recent proposal using the group field theory approach, a spatially homogeneous (generally anisotropic) universe is described as a quantum gravity condensate of "atoms of space," which allows the derivation of an effective cosmological…

General Relativity and Quantum Cosmology · Physics 2015-02-23 Steffen Gielen

In recent work we developed a description of cosmic large scale structure formation in terms of non-equilibrium ensembles of classical particles, with time evolution obtained in the framework of a statistical field theory. In these works,…

Statistical Mechanics · Physics 2018-04-27 Felix Fabis , Elena Kozlikin , Robert Lilow , Matthias Bartelmann

In this review we focus on the main cosmological implications of the Group Field Theory approach, according to which an effective continuum macroscopic dynamics can be extracted from the underlying formalism for quantum gravity. Within this…

General Relativity and Quantum Cosmology · Physics 2022-04-27 Luciano Gabbanelli , Silvia De Bianchi

We present the case for a fundamentally discrete quantum spacetime and for Group Field Theories as a candidate consistent description of it, briefly reviewing the key properties of the GFT formalism. We then argue that the outstanding…

High Energy Physics - Theory · Physics 2008-11-26 Daniele Oriti

In this Letter, we investigate the effects of a time-dependent, short-ranged interaction on the long-time expansion dynamics of Fermi gases. We show that the effects of the interaction on the dynamics is dictated by how it changes under a…

Quantum Gases · Physics 2022-02-02 Jeff Maki , Shizhong Zhang , Fei Zhou

There has been a surge of recent interest in the role of anisotropy in interaction-induced phenomena in two-dimensional (2D) charged carrier systems. A fundamental question is how an anisotropy in the energy-band structure of the carriers…

Mesoscale and Nanoscale Physics · Physics 2017-07-12 Insun Jo , K. A. Villegas Rosales , M. A. Mueed , L. N. Pfeiffer , K. W. West , K. W. Baldwin , R. Winkler , Medini Padmanabhan , M. Shayegan

In a recent paper we discovered that a fermionic condensate is formed from gravitational interactions due to the covariant coupling of fermions in the presence of a torsion-fermion contact interaction. The condensate gap gives a negative…

High Energy Physics - Theory · Physics 2007-05-23 Stephon Alexander , Deepak Vaid

In this thesis, we perform investigations into the behaviour of finite-temperature degenerate Bose gases using a classical-field formalism, focussing in particular on the dynamics of quantum vortices in these systems. We demonstrate that…

Quantum Gases · Physics 2010-11-29 Tod M. Wright

We consider the non-equilibrium dynamics of the entanglement entropy of a one-dimensional quantum gas of hard-core particles, initially confined in a box potential at zero temperature. At $t=0$ the right edge of the box is suddenly released…

Statistical Mechanics · Physics 2021-09-10 Stefano Scopa , Alexandre Krajenbrink , Pasquale Calabrese , Jérôme Dubail

We analyse the emergent cosmological dynamics corresponding to the mean field hydrodynamics of quantum gravity condensates, in the tensorial group field theory formalism. We focus in particular on the cosmological effects of fundamental…

General Relativity and Quantum Cosmology · Physics 2022-01-05 Daniele Oriti , Xiankai Pang

We derive the dynamics of (isotropic) scalar perturbations from the mean-field hydrodynamics of full Lorentzian quantum gravity, as described by a two-sector (timelike and spacelike) Barrett-Crane group field theory (GFT) model. The rich…

General Relativity and Quantum Cosmology · Physics 2024-04-02 Alexander F. Jercher , Luca Marchetti , Andreas G. A. Pithis

We formulate quantum field theory in triangulated spacetime using compositional quantum field theory and tensor network methods. We show that gravitational interactions emerge as a low-energy effective phenomenon in this framework. For…

High Energy Physics - Theory · Physics 2025-05-13 Matti Raasakka