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It is shown that the geometry of quantum theory can be derived from geometrical structure that may be considered more fundamental. The basic elements of this reconstruction of quantum theory are the natural metric on the space of…

Quantum Physics · Physics 2015-06-18 Marcel Reginatto

Assuming the minimal time to send a bit of information in the Einstein clock synchronization of the two clocks located at different positions, we introduce the extended metric to the information space. This modification of relativity…

General Relativity and Quantum Cosmology · Physics 2018-05-01 Akio Hosoya , Shunsuke Fujii

The application of the divergence theorem in a non-coordinated basis is shown to lead to a corrected variational principle for Class B Bianchi cosmological models. This variational principle is used to construct a Hamiltonian formulation…

General Relativity and Quantum Cosmology · Physics 2012-08-27 Michael P. Ryan, , Sergio M. Waller

This paper completes and comments on some aspects of our previous publications. In ref [1], we have derived a set of space-time transformations referred to as the extended space-time transformations. These transformations, which assume the…

General Physics · Physics 2008-03-27 Joseph Levy

We take J. S. Bell's commendation of ``frame-dependent'' perspectives to the limit here, and consider motion on a ``map'' of landmarks and clocks fixed with respect to a single arbitrary inertial-reference frame. The metric equation…

Physics Education · Physics 2008-02-03 P. Fraundorf

Emergent modified gravity presents a new set of generally covariant gravitational theories in which the space-time metric is not directly given by one of the fundamental fields. A metric compatible with the modified dynamics of gravity is…

General Relativity and Quantum Cosmology · Physics 2024-04-09 Martin Bojowald , Erick I. Duque

We show that there exist modified theories of gravity in which the metric satisfies second-order equations and in which the Big Bang singularity is replaced by a cosmic bounce without violating any energy condition. In fact, the bounce is…

General Relativity and Quantum Cosmology · Physics 2010-02-23 Carlos Barragan , Gonzalo J. Olmo , Helios Sanchis-Alepuz

The paper presents an attempt to suggest an alternative way of considering the fundamentals of Einstein's special relativity theory. Its formulation based on introducing an inertial reference system by rigid linking of clocks to a free…

Quantum Physics · Physics 2007-05-23 Ruvin Ferber

We propose a new type of cosmological model derived from the fractional variational principle when it is applied to the gravitational sector of action functional. In contrast to the fractional cosmological model developed earlier by the…

General Relativity and Quantum Cosmology · Physics 2013-04-30 V. K. Shchigolev

By applying Schwinger's variational principle to the Einstein$-$Cartan action for the gravitational field, we derive quantum commutation relations between the metric and torsion tensors.

General Relativity and Quantum Cosmology · Physics 2026-03-11 Nikodem Popławski

Development of the contemporary theory of physical phenomena in the microcosm is considered to be a result of development of Einstein's ideas on a possibility of the event space modification and on a possibility of stochastic (Brownian)…

General Physics · Physics 2007-05-23 Yuri A. Rylov

An introduction to extended theories of gravity formulated in metric-affine (or Palatini) spaces is presented. Focusing on spherically symmetric configurations with electric fields, we will see that in these theories the central singularity…

High Energy Physics - Theory · Physics 2016-07-25 Gonzalo J. Olmo

Alternative gravitational theories described by Lagrangians depending on general functions of the Ricci scalar have been proven to give coherent theoretical models to describe the experimental evidence of the acceleration of universe at…

High Energy Physics - Theory · Physics 2011-07-19 G. Allemandi , A. Borowiec , M. Francaviglia

We present a new variational principle for the gyrokinetic system, similar to the Maxwell-Vlasov action presented in Ref. 1. The variational principle is in the Eulerian frame and based on constrained variations of the phase space fluid…

Plasma Physics · Physics 2013-02-15 J. Squire , H. Qin , W. M. Tang , C. Chandre

Gravity is derived from an entropic action coupling matter fields with geometry. The fundamental idea is to relate the metric of Lorentzian spacetime to a quantum operator, playing the role of an renormalizable effective density matrix and…

General Relativity and Quantum Cosmology · Physics 2025-03-20 Ginestra Bianconi

The method of variational completion allows one to transform an (in principle, arbitrary) system of partial differential equations -- based on an intuitive ``educated guess'' -- into the Euler-Lagrange one attached to a Lagrangian, by…

Mathematical Physics · Physics 2024-06-17 Ludovic Ducobu , Nicoleta Voicu

I present an analysis of the physical assumptions needed to obtain the metric structure of space-time. For this purpose I combine the axiomatic approach pioneered by Robb with ideas drawn from works on Weyl's "Raumproblem". The concept of a…

General Relativity and Quantum Cosmology · Physics 2010-09-29 Jochen Rau

Einstein's vierbein formulation of general relativity based on the notion of distant parallelism (teleparallelism) naturally introduces a covariant surface term in addition to the Einstein-Hilbert action. We investigate the action principle…

General Relativity and Quantum Cosmology · Physics 2017-09-06 Naritaka Oshita , Yi-Peng Wu

We continue our study of the mixed Einstein-Hilbert action as a functional of a pseudo-Riemannian metric and a linear connection. Its geometrical part is the total mixed scalar curvature on a smooth manifold endowed with a distribution or a…

Differential Geometry · Mathematics 2020-07-27 Vladimir Rovenski , Tomasz Zawadzki

Metric-affine theories of gravity provide an interesting alternative to General Relativity: in such an approach, the metric and the affine (not necessarily symmetric) connection are independent quantities. Furthermore, the action should…

General Relativity and Quantum Cosmology · Physics 2012-11-08 Vincenzo Vitagliano , Thomas P. Sotiriou , Stefano Liberati