Results 91 to 100 of about 75,052 (218)

Spaceborne and spaceborn: Physiological aspects of pregnancy and birth during interplanetary flight

open access: yesExperimental Physiology, EarlyView.
Abstract Crewed interplanetary return missions that are on the planning horizon will take years, more than enough time for initiation and completion of a pregnancy. Pregnancy is viewed as a sequence of processes – fertilization, blastocyst formation, implantation, gastrulation, placentation, organogenesis, gross morphogenesis, birth and neonatal ...
Arun V. Holden
wiley   +1 more source

Observational Exclusion of a Consistent Quantum Cosmology Scenario

open access: yes, 2015
It is often argued that inflation erases all the information about what took place before it started. Quantum gravity, relevant in the Planck era, seems therefore mostly impossible to probe with cosmological observations.
Barrau, Aurelien   +3 more
core   +3 more sources

Inflationary Cosmology and Quantization Ambiguities in Semi-Classical Loop Quantum Gravity [PDF]

open access: yes, 2004
In loop quantum gravity, modifications to the geometrical density cause a self-interacting scalar field to accelerate away from a minimum of its potential.
A. Ashtekar   +30 more
core   +3 more sources

Nonadiabatic evolution of primordial perturbations and non-Gaussinity in hybrid approach of loop quantum cosmology [PDF]

open access: yesPhysical Review D, 2018
While loop quantum cosmology (LQC) predicts a robust quantum bounce of the background evolution of a Friedmann-Robertson-Walker (FRW) spacetime prior to the standard slow-roll inflation, whereby the big bang singularity is resolved, there are several ...
Qiang Wu, Tao Zhu, Anzhong Wang
semanticscholar   +1 more source

Mimicking Symmetry‐Breaking Einstein Ring by Optical Lens

open access: yesAdvanced Photonics Research, Volume 6, Issue 6, June 2025.
This article uses an optical lens to emulate the gravitational lensing effect and observe the Einstein ring (ER) patterns. The symmetry‐breaking ER, i.e., Einstein cross, is observed utilizing a rotation‐symmetry‐breaking hemi‐ellipsoid lens. Deformed Einstein cross patterns induced by noncollinearly alignment of the light source–lens–observer are ...
Jun‐Liang Duan   +5 more
wiley   +1 more source

Quantization ambiguities and bounds on geometric scalars in anisotropic loop quantum cosmology [PDF]

open access: yes, 2013
We study quantization ambiguities in loop quantum cosmology that arise for space-times with non-zero spatial curvature and anisotropies. Motivated by lessons from different possible loop quantizations of the closed Friedmann-Lemaitre-Robertson-Walker ...
Singh, Parampreet, Wilson-Ewing, Edward
core   +3 more sources

Phenomenology of loop quantum cosmology [PDF]

open access: yesJournal of Physics: Conference Series, 2010
After introducing the basic ingredients of Loop Quantum Cosmology, I will briefly discuss some of its phenomenological aspects. Those can give some useful insight about the full Loop Quantum Gravity theory and provide an answer to some long-standing questions in early universe cosmology.
openaire   +2 more sources

Tachyonic inflation in loop quantum cosmology

open access: yesEuropean Physical Journal C: Particles and Fields, 2019
A tachyon field might be responsible for cosmological inflation at an early time and contribute to cosmological dark matter at a later time. We investigate tachyonic inflation by analyzing a tachyon field with different potentials in the framework of ...
Kui Xiao
doaj   +1 more source

Thermodynamics in new model of loop quantum cosmology

open access: yesEuropean Physical Journal C: Particles and Fields, 2021
The thermodynamic properties of loop quantum cosmology (LQC) without considering the Lorentz term were established in Li and Zhu (Adv High Energy Phys 2009:905705, 2009).
Xiangdong Zhang
doaj   +1 more source

DeWitt Boundary Condition in One-Loop Quantum Cosmology

open access: yesUniverse, 2023
DeWitt’s suggestion that the wave function of the universe should vanish at the classical Big Bang singularity is considered here within the framework of one-loop quantum cosmology.
Giampiero Esposito
doaj   +1 more source

Home - About - Disclaimer - Privacy