Results 31 to 40 of about 507 (119)

A Non-Polynomial Gravity Formulation for Loop Quantum Cosmology Bounce

Galaxies, 2017
Recently the so-called mimetic gravity approach has been used to obtain corrections to the Friedmann equation of General Relativity similar to the ones present in loop quantum cosmology.
Stefano Chinaglia, Aimeric Colléaux, Sergio Zerbini   +2 more
doaj   +1 more source

A Wheeler–DeWitt Quantum Approach to the Branch-Cut Gravitation with Ordering Parameters

Universe, 2023
In this contribution to the Festschrift for Prof. Remo Ruffini, we investigate a formulation of quantum gravity using the Hořava–Lifshitz theory of gravity, which is General Relativity augmented by counter-terms to render the theory regularized.
Benno August Ludwig Bodmann, César Augusto Zen Vasconcellos, Peter Otto Hess Bechstedt, José Antonio de Freitas Pacheco, Dimiter Hadjimichef, Moisés Razeira, Gervásio Annes Degrazia   +6 more
doaj   +1 more source

Brane-World Gravity

Living Reviews in Relativity, 2004
The observable universe could be a 1+3-surface (the "brane") embedded in a 1+3+$d$-dimensional spacetime (the "bulk"), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk.
Maartens Roy
doaj  

Loop Quantum Cosmology

Living Reviews in Relativity, 2008
Quantum gravity is expected to be necessary in order to understand situations in which classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a ...
Bojowald Martin
doaj  

Loop Quantum Cosmology

Living Reviews in Relativity, 2005
Quantum gravity is expected to be necessary in order to understand situations where classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical
Bojowald Martin
doaj  

Granice fizyki w kosmologii

Zagadnienia Filozoficzne w Nauce, 2015
The message is that physics has an „outward bound” of scientific inquiry in the field of cosmology. I present it in the historical development. Physics and astronomy, developing since the seventeenth century, inherited from the early Greek philosophers ...
Leszek M. Sokołowski
doaj  

Unitary evolution and cosmic acceleration in Loop Quantum Cosmology

Physics Letters B
Loop quantum cosmology was shown to interpolate between de Sitter and FLRW Universe phases through a bounce by including Euclidean and Lorentzian terms of the Hamiltonian constraint with weight one -that corresponding to classical General Relativity ...
Omar Gallegos, Tonatiuh Matos, Hugo A. Morales-Técotl   +2 more
doaj   +1 more source

Matematyka i kosmologia

Zagadnienia Filozoficzne w Nauce, 2012
The mathematical and cosmological works of a group associated with the Copernicus Center for Interdisciplinary Studies in Cracow are summarized. The group consists mainly of M. Heller, L. Pysiak, W. Sasin, Z. Odrzygóźdź and J. Gruszczak.
Michał Heller
doaj  

Complex degenerate metrics in general relativity: a covariant extension of the Moore–Penrose algorithm

European Physical Journal C: Particles and Fields
The Moore–Penrose algorithm provides a generalized notion of an inverse, applicable to degenerate matrices. In this paper, we introduce a covariant extension of the Moore–Penrose method that permits to deal with general relativity involving complex non ...
Arthur Garnier, Emmanuele Battista
doaj   +1 more source

Darkness without dark matter and energy – generalized unimodular gravity

Physics Letters B, 2017
We suggest a Lorentz non-invariant generalization of the unimodular gravity theory, which is classically equivalent to general relativity with a locally inert (devoid of local degrees of freedom) perfect fluid having an equation of state with a constant ...
A.O. Barvinsky, A.Yu. Kamenshchik
doaj   +1 more source