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相关论文: Effective cosmology from one-body operators in gro…

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We extend various recent results regarding the derivation of effective cosmological Friedmann equations from the dynamics of group field theory (GFT). Restricting ourselves to a single GFT field mode (or fixed values of Peter-Weyl…

广义相对论与量子宇宙学 · 物理学 2022-01-11 Steffen Gielen , Axel Polaczek

We derive an effective dynamics for scalar cosmological perturbations from quantum gravity, in the framework of group field theory (GFT) condensate cosmology. The emergent spacetime picture is obtained from the mean field hydrodynamic…

广义相对论与量子宇宙学 · 物理学 2022-07-19 Luca Marchetti , Daniele Oriti

We analyze the size and evolution of quantum fluctuations of cosmologically relevant geometric observables, in the context of the effective relational cosmological dynamics of GFT models of quantum gravity. We consider the fluctuations of…

广义相对论与量子宇宙学 · 物理学 2021-09-23 Luca Marchetti , Daniele Oriti

We identify a class of condensate states in the group field theory (GFT) approach to quantum gravity that can be interpreted as macroscopic homogeneous spatial geometries. We then extract the dynamics of such condensate states directly from…

广义相对论与量子宇宙学 · 物理学 2013-07-17 Steffen Gielen , Daniele Oriti , Lorenzo Sindoni

In loop quantum cosmology, Friedmann-LeMaitre-Robertson-Walker (FLRW) space-times arise as well-defined approximations to specific \emph{quantum} geometries. We initiate the development of a quantum theory of test scalar fields on these…

广义相对论与量子宇宙学 · 物理学 2009-11-06 Abhay Ashtekar , Wojciech Kaminski , Jerzy Lewandowski

We use the ideas of entropic gravity to derive the FRW cosmological model and show that for late time evolution we have an effective cosmological constant. By using the first law of thermodynamics and the modified entropy area relationship…

广义相对论与量子宇宙学 · 物理学 2018-06-15 I. Díaz-Saldaña , J. López-Domínguez , M. Sabido

We present a simple model of quantum cosmology based on the group field theory (GFT) approach to quantum gravity. The model is formulated on a subspace of the GFT Fock space for the quanta of geometry, with a fixed volume per quantum. In…

广义相对论与量子宇宙学 · 物理学 2018-04-17 Eugene Adjei , Steffen Gielen , Wolfgang Wieland

The quantized Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) model minimally coupled to a free massless scalar field is studied and interpreted in the Bohm-de Broglie framework. We analyze the quantum bohmian trajectories corresponding to…

广义相对论与量子宇宙学 · 物理学 2016-11-09 E. Sergio Santini

By using a solution ansatz we partially decouple the metric and the Stuckelberg sectors of the minimal massive gravity (MMGR). In this scheme for a diagonal physical metric we find the general solutions for the scalars of the theory and the…

高能物理 - 理论 · 物理学 2015-05-19 Nejat Tevfik Yilmaz

We present a unified dynamical systems framework for spatially flat FLRW cosmology in $f(Q)$ gravity, covering all three connection branches via a single set of Hubble-normalised variables without fixing $f(Q)$ \textit{a priori}. This…

广义相对论与量子宇宙学 · 物理学 2025-12-17 Jibitesh Dutta , Wompherdeiki Khyllep , Saikat Chakraborty , Daniele Gregoris , Khamphee Karwan

We show that the simplest FLRW cosmological system consisting in the homogeneous and isotropic massless Einstein-Scalar system enjoys a hidden conformal symmetry under the 1D conformal group $SL(2,\mathbb{R})$ acting as Mobius…

广义相对论与量子宇宙学 · 物理学 2025-02-06 Jibril Ben Achour , Etera R. Livine

In an open Friedmann-Robertson-Walker (FRW) space background, we study the classical and quantum cosmological models in the framework of the recently proposed nonlinear massive gravity theory. Although the constraints which are present in…

广义相对论与量子宇宙学 · 物理学 2015-06-04 Babak Vakili , Nima Khosravi

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…

广义相对论与量子宇宙学 · 物理学 2014-06-06 Steffen Gielen , Daniele Oriti , Lorenzo Sindoni

We study FLRW cosmology, taking into account quantum gravitational corrections in the formalism of the exact renormalization group flow of the effective action for gravity. We calculate the quantum corrected scale factor, energy density,…

广义相对论与量子宇宙学 · 物理学 2022-10-26 Rituparna Mandal , Sunandan Gangopadhyay , Amitabha Lahiri

We examine Friedmann-Lema\^itre-Robertson-Walker cosmology, incorporating quantum gravitational corrections through the functional renormalization group flow of the effective action for gravity. We solve the Einstein equation with quantum…

广义相对论与量子宇宙学 · 物理学 2025-10-15 Chiang-Mei Chen , Rituparna Mandal , Nobuyoshi Ohta

Considering the Friedmann--Lema\^{i}tre--Robertson--Walker (FLRW) metric and the Einstein scalar field system as an underlying gravitational model to construct fractional cosmological models has interesting implications in both classical…

广义相对论与量子宇宙学 · 物理学 2024-07-26 S. M. M. Rasouli , S. Cheraghchi , P. V. Moniz

We give, in some detail, a critical overview over recent work towards deriving a cosmological phenomenology from the fundamental quantum dynamics of group field theory (GFT), based on the picture of a macroscopic universe as a "condensate"…

广义相对论与量子宇宙学 · 物理学 2016-08-19 Steffen Gielen , Lorenzo Sindoni

This article explores the cosmological scenario of the universe in the context of the $f(T)$ power law model, where $T$ represent the torsion scalar. To obtain the deterministic solution of the field equations we parametrized the effective…

广义相对论与量子宇宙学 · 物理学 2024-11-11 S. R. Bhoyar , Yash B. Ingole

Quantum cosmology based on the Wheeler De Witt equation represents a simple way to implement plausible quantum effects in a gravitational setup. In its minisuperspace version wherein one restricts attention to FLRW metrics with a single…

广义相对论与量子宇宙学 · 物理学 2019-02-05 Patrick Peter

We present a Friedmann-Robertson-Walker (FRW) quantum cosmological model within the framework of Finslerian geometry. In this work, we consider a specific fluid. We obtain the corresponding Wheeler-DeWitt equation as the usual constraint…

综合物理 · 物理学 2019-11-04 S S De , Farook Rahaman , Nupur Paul
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