Results 121 to 130 of about 75,052 (218)

New Hamiltonian constraint operator for loop quantum gravity

open access: yesPhysics Letters B, 2015
A new symmetric Hamiltonian constraint operator is proposed for loop quantum gravity, which is well defined in the Hilbert space of diffeomorphism invariant states up to non-planar vertices with valence higher than three. It inherits the advantage of the
Jinsong Yang, Yongge Ma
doaj   +1 more source

From the conformal anomaly to the Virasoro algebra

open access: yesProceedings of the London Mathematical Society, Volume 130, Issue 4, April 2025.
Abstract The conformal anomaly and the Virasoro algebra are fundamental aspects of two‐dimensional conformal field theory and conformally covariant models in planar random geometry. In this article, we explicitly derive the Virasoro algebra from an axiomatization of the conformal anomaly in terms of real determinant lines, one‐dimensional vector spaces
Sid Maibach, Eveliina Peltola
wiley   +1 more source

Tsallis, Rényi and Sharma-Mittal Holographic Dark Energy Models in Loop Quantum Cosmology

open access: yesSymmetry, 2018
The cosmic expansion phenomenon is being studied through the interaction of newly proposed dark energy models (Tsallis, Rényi and Sharma-Mittal holographic dark energy (HDE) models) with cold dark matter in the framework of loop quantum cosmology.
A. Jawad   +4 more
semanticscholar   +1 more source

Scalar spectra of primordial perturbations in loop quantum cosmology [PDF]

open access: yesPhysical Review D, 2018
This article is devoted to the study of scalar perturbations in loop quantum cosmology. It aims at clarifying the situation with respect to the way initial conditions are set and to the specific choice of an inflaton potential.
A. Barrau   +3 more
semanticscholar   +1 more source

Euler–Heisenberg Black Hole Surrounded by Quintessence in the Background of Perfect Fluid Dark Matter: Thermodynamics, Shadows, and Quasinormal Modes

open access: yesFortschritte der Physik, Volume 73, Issue 3, March 2025.
Abstract Current observations show that a significant fraction of the Universe is composed of dark energy and dark matter. In this paper, the simultaneous effects of these dark sectors on the Euler–Heisenberg black hole are investigated, using the quintessence matter field and perfect fluid to model them. In particular, the black hole's thermodynamics,
Bilel Hamil, Bekir Can Lütfüoğlu
wiley   +1 more source

No-boundary wave function for loop quantum cosmology [PDF]

open access: yesPhysical Review D, 2018
Proposing smooth initial conditions is one of the most important tasks in quantum cosmology. On the other hand, the low-energy effective action, appearing in the semiclassical path integral, can get nontrivial quantum corrections near classical ...
Suddhasattwa Brahma, Dong-han Yeom
semanticscholar   +1 more source

Visible GeV ALP from TeV Vector‐Like Leptons

open access: yesFortschritte der Physik, Volume 73, Issue 3, March 2025.
Abstract A model is presented where a GeV axion‐like‐particle (ALP) is predicted in a large portion of the parameter space due to the presence of explicit Peccei–Quinn (PQ) symmetry‐breaking terms in an exotic leptonic sector. The latter provides a solution to the muon g−2$g-2$ anomaly, within the framework of the Linear Seesaw neutrino mechanism.
Arturo de Giorgi   +2 more
wiley   +1 more source

Inhomogeneous Loop Quantum Cosmology: Hybrid Quantization of the Gowdy Model [PDF]

open access: yes, 2010
The Gowdy cosmologies provide a suitable arena to further develop Loop Quantum Cosmology, allowing the presence of inhomogeneities. For the particular case of Gowdy spacetimes with the spatial topology of a three-torus and a content of linearly polarized
A. Ashtekar   +6 more
core   +4 more sources

Mathematical Structure of Loop Quantum Cosmology: Homogeneous Models

open access: yesSymmetry, Integrability and Geometry: Methods and Applications, 2013
The mathematical structure of homogeneous loop quantum cosmology is analyzed, starting with and taking into account the general classification of homogeneous connections not restricted to be Abelian.
Martin Bojowald
doaj   +1 more source

Purpose and Providence in Evolutionary Perspective: Considerations for Theological Anthropology in Light of Biocultural Evolution and Genetic Engineering

open access: yesThe Heythrop Journal, Volume 66, Issue 2, Page 157-173, March 2025.
Abstract We argue here that bringing insights from evolution and bioengineering to bear on traditional accounts of divine providence helps to illustrate just how complex providence is and how difficult it is to achieve. While other non‐human animals might exhibit greater agency in creation and its evolutionary development than has traditionally been ...
Michael Burdett, Andrew Jackson
wiley   +1 more source

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