Results 11 to 20 of about 20,249 (29)

Relational Motivation for Conformal Operator Ordering in Quantum Cosmology

, 2009
Operator-ordering in quantum cosmology is a major as-yet unsettled ambiguity with not only formal but also physical consequences. We determine the Lagrangian origin of the conformal invariance that underlies the conformal operator-ordering choice in ...
Anderson, Edward
core   +1 more source

Loop quantum gravity corrections to gravitational wave dispersion [PDF]

, 1997
Cosmological tensor perturbations equations are derived for Hamiltonian cosmology based on Ashtekar's formulation of general relativity, including typical quantum gravity effects in the Hamiltonian constraint as they are expected from loop quantum ...
Bojowald, Martin, Hossain, Golam Mortuza
core   +3 more sources

Singularities and Quantum Gravity

, 2007
Although there is general agreement that a removal of classical gravitational singularities is not only a crucial conceptual test of any approach to quantum gravity but also a prerequisite for any fundamental theory, the precise criteria for non-singular
Bojowald, Martin
core   +2 more sources

(Loop) quantum gravity and the inflationary scenario [PDF]

, 2015
Quantum gravity, as a fundamental theory of space-time, is expected to reveal how the universe may have started, perhaps during or before an inflationary epoch.
Bojowald, Martin
core   +2 more sources

Switching internal times and a new perspective on the 'wave function of the universe'

, 2019
Despite its importance in general relativity, a quantum notion of general covariance has not yet been established in quantum gravity and cosmology, where, given the a priori absence of coordinates, it is necessary to replace classical frames with ...
Hoehn, Philipp A
core   +1 more source

Quantum Inflation of Classical Shapes [PDF]

, 2014
I consider a quantum system that possesses key features of quantum shape dynamics and show that the evolution of wave-packets will become increasingly classical at late times and tend to evolve more and more like an expanding classical system.
Koslowski, Tim A.
core  

Nonmetricity formulation of general relativity and its scalar-tensor extension

, 2018
Einstein's celebrated theory of gravitation can be presented in three forms: general relativity, teleparallel gravity, and the rarely considered before symmetric teleparallel gravity.
Järv, Laur, Rünkla, Mihkel, Saal, Margus, Vilson, Ott   +3 more
core   +1 more source

The Semiclassical Limit of Loop Quantum Cosmology [PDF]

, 2001
The continuum and semiclassical limits of isotropic, spatially flat loop quantum cosmology are discussed, with an emphasis on the role played by the Barbero-Immirzi parameter \gamma in controlling space-time discreteness.
Ashtekar A, Ashtekar A, Ashtekar A, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bombelli L, Bombelli L, Corichi A, Karasev M V, Martin Bojowald, Rovelli C, Sahlmann H, Thiemann T, Thiemann T, Varadarajan M   +20 more
core   +3 more sources

Hubble operator in isotropic loop quantum cosmology

, 2003
We present a construction of the Hubble operator for the spatially flat isotropic loop quantum cosmology. This operator is a Dirac observable on a subspace of the space of physical solutions.
Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M Vandersloot K, Date G, Dirac P A M, Fernando J, Gaul M, Golam Mortuza Hossain, Immirzi G, Kodama H, Misner C W, Perez A Rovelli C, Rovelli C, Rovelli C, Smolin L, Thiemann T, Thiemann T, Thiemann T   +26 more
core   +1 more source

Group field theory condensate cosmology: An appetizer

, 2019
This contribution is an appetizer to the relatively young and fast evolving approach to quantum cosmology based on group field theory condensate states. We summarize the main assumptions and pillars of this approach which has revealed new perspectives on
Pithis, A. G. A., Sakellariadou, M.
core   +1 more source