English
Related papers

Related papers: Cosmological constant from quantum spacetime

200 papers

We start from classical Hamiltonian constraint of general relativity to obtain the Einstein-Hamiltonian-Jacobi equation. We obtain a time parameter prescription demanding that geometry itself determines the time, not the matter field, such…

General Relativity and Quantum Cosmology · Physics 2015-06-25 S. Biswas , A. Shaw , B. Modak , D. Biswas

We investigate the line element of spacetime around a linear cosmic string in the presence of a cosmological constant. We obtain the metric and argue that it should be discarded because of asymptotic considerations. Then a time dependent…

General Relativity and Quantum Cosmology · Physics 2009-01-05 Amir H. Abbassi , Amir M. Abbassi

We generalize the well-known Bonnor-Melvin solution of the Einstein-Maxwell equations to the case of a non-vanishing cosmological constant. The spacetime is again cylindrically symmetric and static but, unlike the original solution, it…

General Relativity and Quantum Cosmology · Physics 2019-03-21 Martin Zofka

The dynamics of the expanding universe is analyzed in terms of the quantum geometrodynamical model. It is shown that the equations of quantum theory in the form of the eigenvalues equation similar to the stationary Schr\"{o}dinger equation…

General Relativity and Quantum Cosmology · Physics 2013-11-22 V. E. Kuzmichev , V. V. Kuzmichev

We study the quantum cosmology of a flat Friedmann-Lema\^{i}tre-Robertson-Walker universe filled with a (free) massless scalar field and a perfect fluid that represents radiation or a cosmological constant whose value is not fixed by the…

General Relativity and Quantum Cosmology · Physics 2020-10-01 Steffen Gielen , Lucía Menéndez-Pidal

It is very likely that the quantum description of spacetime is quite different from what we perceive at large scales, $l\gg (G\hbar/c^3)^{1/2}$. The long wave length description of spacetime, based on Einstein's equations, is similar to the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 T. Padmanabhan

In this paper we study how to include the cosmological constant in geometric scalar theory of gravity (GSG). Firstly we show that the cosmological constant could not be modeled by a matter field, unlike in General Relativity. We also show…

General Relativity and Quantum Cosmology · Physics 2015-09-11 I. C. Jardim , R. R. Landim

We introduce observables associated with the space-time position of a quantum point defined by the intersection of two light pulses. The time observable is canonically conjugated to the energy. Conformal symmetry of massless quantum fields…

Quantum Physics · Physics 2009-10-30 Marc-Thierry Jaekel , Serge Reynaud

The algebras of non-relativistic and of classical mechanics are unstable algebraic structures. Their deformation towards stable structures leads, respectively, to relativity and to quantum mechanics. Likewise, the combined relativistic…

Mathematical Physics · Physics 2009-10-31 R. Vilela Mendes

Physical spacetime geometry follows from some effective thermodynamics of quantum states of all fields and particles described in frames of General Relativity. In the sense of pure field theoretical Einstein's point of view on gravitation…

General Relativity and Quantum Cosmology · Physics 2008-08-27 L. A. Glinka

A scale invariant, Weyl geometric, Lagrangian approach to cosmology is explored, with a a scalar field phi of (scale) weight -1 as a crucial ingredient besides classical matter \cite{Tann:Diss,Drechsler:Higgs}. For a particularly simple…

Astrophysics · Physics 2009-11-18 Erhard Scholz

In absence of matter Einstein gravity with a cosmological constant $\La$ can be formulated as a scale-free theory depending only on the dimensionless coupling constant G \Lambda where G is Newton constant. We derive the conformal field…

High Energy Physics - Theory · Physics 2009-11-11 Mariano Cadoni

We show that a positive cosmological constant is incompatible with the quantum-corpuscular resolution of de Sitter metric in form of a coherent state. The reason is very general and is due to the quantum self-destruction of the coherent…

High Energy Physics - Theory · Physics 2014-12-30 Gia Dvali , Cesar Gomez

We argue that quantum theory should proceed not from a spacetime background but from a Lie algebra, which is treated as a symmetry algebra. Then the fact that the cosmological constant is positive means not that the spacetime background is…

General Physics · Physics 2021-09-06 Felix M. Lev

In the context of the Relativistic Quantum Geometry formalism, where the cosmological constant is promoted to a dynamical variable by attributing it a geometric interpretation as a result of a flux on the boundary of a manifold and…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Juan Ignacio Musmarra , Claudia Moreno , Rafael Hernández-Jiménez

A contribution of quantum vacuum to the energy momentum tensor is inevitably experienced in the present universe. One requires the presence of non-zero cosmological constant ($\Lambda$) to make the various observations consistent. A case of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ishwaree P. Neupane

Much of twentieth century physics, whether it be Classical or Quantum, has been based on the concept of spacetime as a differentiable manifold. While this work has culminated in the standard model, it is now generally accepted that in the…

General Physics · Physics 2007-05-23 B. G. Sidharth

A modification of the Einstein-Hilbert theory, the Covariant Canonical Gauge Gravity (CCGG), leads to a cosmological constant that represents the energy of the space-time continuum when deformed from its (A)dS ground state to a flat…

General Relativity and Quantum Cosmology · Physics 2023-11-28 D. Vasak , J. Kirsch , J. Struckmeier , H. Stoecker

We introduce the notion of background independent quantum field theory. The distinguishing feature of this theory is that the dynamics can be formulated without recourse to a background metric structure. We show in a simple model how the…

High Energy Physics - Theory · Physics 2007-05-23 Olaf Dreyer

We study homogeneous cosmological models in formulations of general relativity with cosmological constant based on a (complexified) connection rather than a spacetime metric, in particular in a first order theory obtained by integrating out…

General Relativity and Quantum Cosmology · Physics 2023-05-10 Steffen Gielen , Elliot Nash
‹ Prev 1 8 9 10 Next ›