English
Related papers

Related papers: Energy-momentum and dark energy in $\boldsymbol{SU…

200 papers

$SU(\infty)-QGR$ is a foundationally quantum approach to cosmology and gravity. It assumes that the Hilbert space of the Universe as a whole represents the symmetry group $SU(\infty)$, and demonstrates this symmetry for Hilbert spaces of…

General Relativity and Quantum Cosmology · Physics 2025-02-21 Houri Ziaeepour

We highlight the structure and properties of an abstract approach to quantum cosmology and gravity, dubbed $SU(\infty)$-QGR. Beginning from the concept of the Universe as an isolated quantum system, the main axiom of is the existence of an…

General Relativity and Quantum Cosmology · Physics 2025-05-27 Houri Ziaeepour

Our Universe is ruled by quantum mechanics and should be treated as a quantum system. $SU(\infty)$-QGR is a recently proposed quantum model for the Universe, in which gravity is associated to $SU(\infty)$ symmetry of its Hilbert space.…

General Relativity and Quantum Cosmology · Physics 2025-05-27 Houri Ziaeepour

$SU(\infty)$-QGR is a quantum approach to Universe and gravity. Its main assumption is infinite mutually commuting observables in the Universe, leading to representation of $SU(\infty)$ by its Hilbert spaces and those of its subsystems. The…

General Relativity and Quantum Cosmology · Physics 2023-04-07 Houri Ziaeepour

In a previous work [arXiv:2009.03428] we proposed a new model for Quantum GRavity(QGR) and cosmology, dubbed $SU(\infty)$-QGR. One of the axioms of this model is that Hilbert spaces of the Universe and its subsystems represent $SU(\infty)$…

General Relativity and Quantum Cosmology · Physics 2022-01-04 Houri Ziaeepour

So far, none of attempts to quantize gravity has led to a satisfactory model that not only describe gravity in the realm of a quantum world, but also its relation to elementary particles and other fundamental forces. Here, we outline the…

General Relativity and Quantum Cosmology · Physics 2021-11-29 Houri Ziaeepour

We use the idea of the symmetry between the spacetime coordinates x^\mu and the energy-momentum p^\mu in quantum theory to construct a momentum space quantum gravity geometry with a metric s_{\mu\nu} and a curvature P^\lambda_{\mu\nu\rho}.…

General Relativity and Quantum Cosmology · Physics 2016-03-08 J. W. Moffat

We start with the Hamiltonian formulation of the first order action of pure gravity with a full $\mathfrak{sl}(2,\mathbb C)$ internal gauge symmetry. We make a partial gauge-fixing which reduces $\mathfrak{sl}(2,\mathbb C)$ to its…

General Relativity and Quantum Cosmology · Physics 2017-06-28 Hongguang Liu , Karim Noui

We construct a model of quantum gravity in which dimension, topology and geometry of spacetime are dynamical. The microscopic degree of freedom is a real rectangular matrix whose rows label internal flavours, and columns label spatial…

High Energy Physics - Theory · Physics 2020-12-14 Sung-Sik Lee

In this work we propose the $f(Q,T_{\mu\nu}T^{\mu\nu})$ gravity as a further extension of the $f(Q)$ and $f(Q,T)$ gravity theories. The action involves an arbitrary function of the non-metricity $Q$ and $T_{\mu\nu}T^{\mu\nu}$ in the gravity…

General Relativity and Quantum Cosmology · Physics 2022-06-22 Prabir Rudra

The quantization of the reduced phase-space of the Einstein-Hilbert action for gravity in $2+1D$ has been shown to bring about the emergence, at the quantum level, of a topological quantum field theory endowed with an $SU_q(2)$ quantum…

General Relativity and Quantum Cosmology · Physics 2023-03-08 Niels Gresnigt , Antonino Marciano , Emanuele Zappala

One of the standard approaches of incorporating the quantum gravity (QG) effects into the semiclassical analysis is to adopt the notion of a quantum-corrected spacetime arising from the QG model. This procedure assumes that the expectation…

General Relativity and Quantum Cosmology · Physics 2023-12-29 Harkirat Singh Sahota , Kinjalk Lochan

We present in detail a four-dimensional unified quantum theory. In this theory, we identify three class of parameters, coordinate-momentum, spin and gauge, as all and as the only fundamental parameters to describe quantum fields. The…

General Physics · Physics 2009-11-23 Chang-Yu Zhu , Heng Fan

We study de Sitter JT gravity in the canonical formulation to illustrate constructions of Hilbert spaces in quantum gravity, which is challenging due to the Hamiltonian constraints. The key ideas include representing states as "invariants"…

High Energy Physics - Theory · Physics 2025-10-17 Jesse Held , Henry Maxfield

In this study, we examine the energy-momentum squared modified theory of gravity, where the squared term $T_{\mu\nu}T^{\mu\nu}$ is incorporated into the conventional gravitational Lagrangian. This modification aims to account for dark…

General Relativity and Quantum Cosmology · Physics 2025-02-03 H. R. Fazlollahi , H. Velten , H. Shojaie

This paper elaborates on an intrinsically quantum approach to gravity, which begins with a general framework for quantum mechanics and then seeks to identify additional mathematical structure on Hilbert space that is responsible for gravity…

High Energy Physics - Theory · Physics 2019-03-27 Steven B. Giddings

The quantum geometric tensor (QGT) characterizes the Hilbert space geometry of the eigenstates of a parameter-dependent Hamiltonian. In recent years, the QGT and related quantities have found extensive theoretical and experimental utility,…

Statistical Mechanics · Physics 2024-11-20 Rustem Sharipov , Anastasiia Tiutiakina , Alexander Gorsky , Vladimir Gritsev , Anatoli Polkovnikov

In this work, we present a review of Energy-Momentum Squared Gravity (EMSG) -- more specifically, $f(R,T_{\mu\nu}T^{\mu\nu})$ gravity, where $R$ represents the Ricci scalar and $T_{\mu\nu}$ denotes the energy-momentum tensor. The inclusion…

General Relativity and Quantum Cosmology · Physics 2024-08-27 Ricardo A. C. Cipriano , Nailya Ganiyeva , Tiberiu Harko , Francisco S. N. Lobo , Miguel A. S. Pinto , João Luís Rosa

First, we describe the construction of a new type of gravity-matter models based on the formalism of non-Riemannian space-time volume forms - alternative generally covariant integration measure densities (volume elements) defined in terms…

General Relativity and Quantum Cosmology · Physics 2017-12-29 Eduardo Guendelman , Emil Nissimov , Svetlana Pacheva

Based on a family of indefinite unitary representations of the diffeomorphism group of an oriented smooth $4$-manifold, a manifestly covariant $4$ dimensional and non-perturbative algebraic quantum field theory formulation of gravity is…

High Energy Physics - Theory · Physics 2017-01-18 Gabor Etesi
‹ Prev 1 2 3 10 Next ›