Results 41 to 50 of about 467 (173)
, 2014 To appear as a Chapter of "The Springer Handbook of Spacetime," edited by A. Ashtekar and V. Petkov. (Springer-Verlag, at Press).
Agullo, Ivan, Corichi, Alejandro
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Guiding and Manipulating Light Fields in Microstructured Liquid Crystals
Advanced Physics Research, EarlyView.This review summarizes recent advances in guided‐wave optics enabled by microstructured liquid crystal (LC) devices, covering their fundamental material properties, key degree of freedom for dynamic light field manipulations. The advances of linear guided‐wave optics, nonlinear‐optics with spatial optical solitons, and microlasers in LC‐based devices ...
Shan‐shan Chang +2 more
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Loop quantum cosmology: I. Kinematics [PDF]
Classical and Quantum Gravity, 2000 The framework of quantum symmetry reduction is applied to loop quantum gravity with respect to transitively acting symmetry groups. This allows to test loop quantum gravity in a large class of minisuperspaces and to investigate its features - e.g. the discrete volume spectrum - in certain cosmological regimes.
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Probability of inflation in loop quantum cosmology [PDF]
General Relativity and Gravitation, 2011 34 pages, 3 ...
Ashtekar, Abhay, Sloan, David
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Tachyonic inflation in loop quantum cosmology
European 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
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Frontiers in Astronomy and Space Sciences, 2021 While the standard, six-parameter, spatially flat ΛCDM model has been highly successful, certain anomalies in the cosmic microwave background bring out a tension between this model and observations.
Abhay Ashtekar +3 more
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Magnetic properties of geraisites, the first tektite strewn field identified in Brazil
Meteoritics &Planetary Science, EarlyView.Abstract Geraisites are a newly recognized class of tektite from Brazil. They occur as centimeter‐sized, elongated to subspherical bodies scattered across surface gravel and shallow subsurface layers within a ~90‐km‐long strewn field extending between the municipalities of São João do Paraíso and Curral de Dentro, near the border between the states of ...
Melissa De Andrade Nunes +7 more
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Nonlinear (loop) quantum cosmology
Physical Review D, 2012 Inhomogeneous quantum cosmology is modeled as a dynamical system of discrete patches, whose interacting many-body equations can be mapped to a non-linear minisuperspace equation by methods analogous to Bose-Einstein condensation. Complicated gravitational dynamics can therefore be described by more-manageable equations for finitely many degrees of ...
Bojowald, Martin +4 more
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Universal features of quantum bounce in loop quantum cosmology
Physics Letters B, 2017 In this Letter, we study analytically the evolutions of the flat Friedmann–Lemaitre–Robertson–Walker (FLRW) universe and its linear perturbations in the framework of the dressed metric approach in loop quantum cosmology (LQC). Assuming that the evolution
Tao Zhu +4 more
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Nanoscale space weathering features in mature lunar soil revealed by TEM and APT
Meteoritics &Planetary Science, EarlyView.Abstract Space weathering significantly alters the optical, chemical, and structural properties of lunar regolith at micro‐ and nanoscales; yet detailed nanoscale variability within individual soils remains underexplored. Here we apply transmission electron microscopy (TEM) and atom probe tomography to four mineral grains (olivine, ilmenite, and two ...
Jennika Greer +6 more
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