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Related papers: The Time Surface Term in Quantum Gravity

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Deformations of minimal surfaces lying in constant time slices in static space-times are studied. An exact and universal formula for a change of the area of a minimal surface under shifts of nearby point-like particles is found. It allows…

High Energy Physics - Theory · Physics 2014-11-21 Dmitri V. Fursaev

Our recent theory (Ref. 1) enables us to choose arbitrary quantities as the basic variables of the density functional theory. In this paper we apply it to several cases. In the case where the occupation matrix of localized orbitals is…

Materials Science · Physics 2009-11-10 K. Higuchi , M. Higuchi

The Einstein-Hilbert action has a bulk term and a surface term (which arises from integrating a four divergence). I show that one can obtain Einstein's equations from the surface term alone. This leads to: (i) a novel, completely self…

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

In the context of thermodynamics applied to our cosmological apparent horizon, we explicit in greater details our previous work which established the Friedmann Equations from projection of Hayward's Unified First Law. In particular, we show…

General Relativity and Quantum Cosmology · Physics 2015-02-17 Alexis Helou

Scale invariance is considered in the context of gravitational theories where the action, in the first order formalism, is of the form $S = \int L_{1} \Phi d^4x$ + $\int L_{2}\sqrt{-g}d^4x$ where the volume element $\Phi d^4x$ is…

High Energy Physics - Theory · Physics 2007-05-23 E. I. Guendelman

It is possible to describe a universal scalar field of time but not a universal coordinate of time and to attribute its non-geodesic alignment to the electromagnetic phenomena. A very surprising outcome is that not only mass generates…

General Physics · Physics 2025-09-29 Eytan H. Suchard

We derive the scalar-tensor Hamiltonian constraint to all orders of momenta when the canonical constraint algebra is deformed by a phase space function as predicted by some studies into loop quantum cosmology. We find that the momenta and…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Rhiannon Cuttell , Mairi Sakellariadou

A new covariant generalization of Einstein's general relativity is developed which allows the existence of a term proportional to $T_{\alpha\beta}T^{\alpha\beta}$ in the action functional of the theory ($T_{\alpha\beta}$ is the…

General Relativity and Quantum Cosmology · Physics 2016-08-04 Mahmood Roshan , Fatimah Shojai

Evolution of the scale factor a(t) in Friedmann models (those with zero pressure and a constant cosmological term Lambda) is well understood, and elegantly summarized in the review of Felten and Isaacman [Rev. Mod. Phys. 58, 689 (1986)].…

Astrophysics · Physics 2008-11-26 J. M. Overduin , F. I. Cooperstock

We use graphical field gradients in an adynamical, background independent fashion to propose a new approach to quantum gravity and unification. Our proposed reconciliation of general relativity and quantum field theory is based on a…

Quantum Physics · Physics 2015-04-01 W. M. Stuckey , Michael Silberstein , Timothy McDevitt

A version of the cosmological perturbation theory in general relativity (GR) is developed, where the cosmological scale factor is identified with spatial averaging of the metric determinant logarithm and the cosmic evolution acquires the…

General Relativity and Quantum Cosmology · Physics 2011-07-19 B. M. Barbashov , V. N. Pervushin , A. F. Zakharov , V. A. Zinchuk

Refraction, interference, and diffraction serve as distinguishing features for wave-like phenomena. While they are normally associated only with a purely spatial wave-propagation pattern, analogs to interference and diffraction involving…

Quantum Physics · Physics 2011-05-17 M. Jaaskelainen , M. Lombard , U. Zuelicke

Quantum operators of coordinates and momentum components of a particle in Minkowski space-time belong to a noncommutative algebra and give rise to a quantum phase space. Under some constraints, in particular, the Lorentz invariance…

High Energy Physics - Theory · Physics 2009-10-20 V. V. Khruschov

We study perfect fluid Stephani quantum cosmological model. In the present work the Schutz's variational formalism which recovers the notion of time is applied. This gives rise to Wheeler-DeWitt equation for the scale factor. We use the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 P. Pedram , S. Jalalzadeh , S. S. Gousheh

We review how reparametrization of space and time, namely the procedure where both are made to depend on yet another parameter, can be used to formulate quantum physics in a way that is naturally conducive to relativity. This leads us to a…

Quantum Physics · Physics 2020-09-24 Vlatko Vedral

Positive-energy solutions of the Klein-Gordon equation form a Hilbert space of holomorphic functions on the future tube. This domain is interpreted as an extended phase space for the associated classical particle, the extra dimensions being…

Mathematical Physics · Physics 2023-05-23 Gerald Kaiser

Doplicher, Fredenhagen, and Roberts (1994, 1995) proposed a simple model of a particle in quantum spacetime. We give a new formulation of the model and propose some small changes and additions which improve the physical interpretation. In…

High Energy Physics - Theory · Physics 2008-11-26 Jan Naudts , Maciej Kuna

Our attempts to find an explanation for quantum behavior of the Early Universe appeal, as a rule, to the Wheeler - DeWitt Quantum Geometrodynamics which relies upon Hamiltonian formulation of General Relativity proposed by Arnowitt, Deser…

General Relativity and Quantum Cosmology · Physics 2013-02-21 T. P. Shestakova

We explore the canonical description of a scalar field as a parameterized field theory on an extended phase space that includes additional embedding fields that characterize spacetime hypersurfaces $\mathsf{X}$ relative to which the scalar…

Quantum Physics · Physics 2023-11-27 Philipp A. Hoehn , Andrea Russo , Alexander R. H. Smith

Spacetime foam is analyzed within the simplistic model of a set of scalar fields on a flat background. We suggest the formula for the path integral which allows to account for the all possible topologies of spacetime. We show that the…

General Relativity and Quantum Cosmology · Physics 2008-09-11 A. A. Kirillov , E. P. Savelova
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