Results 81 to 90 of about 180,985 (262)
Trans-Planckian problem of inflationary cosmology [PDF]
, 2000 In most current models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, the period of inflation lasts so long that, at the beginning of the inflationary period, the physical wavelengths of comoving scales ...
Jérôme Martin, R. Brandenberger
semanticscholar +1 more source
Lessons from the void: What Boltzmann brains teach
Analytic Philosophy, Volume 66, Issue 4, Page 594-621, December 2025.Abstract Some physical theories predict that almost all brains in the universe are Boltzmann brains, that is, short‐lived disembodied brains that are accidentally assembled as a result of thermodynamic or quantum fluctuations. Physicists and philosophers of physics widely regard this proliferation as unacceptable, and so take its prediction as a basis ...
Bradford Saad
wiley +1 more source
WMAP normalization of inflationary cosmologies [PDF]
Physical Review D, 2006 We use the three-year WMAP observations to determine the normalization of the matter power spectrum in inflationary cosmologies. In this context, the quantity of interest is not the normalization marginalized over all parameters, but rather the normalization as a function of the inflationary parameters n and r with marginalization over the remaining ...
Liddle, Andrew R. +3 more
openaire +4 more sources
Physics Letters B, 2019 Combining intervals of ekpyrotic (ultra-slow) contraction with a (non-singular) classical bounce naturally leads to a novel cyclic theory of the universe in which the Hubble parameter, energy density and temperature oscillate periodically, but the scale ...
Anna Ijjas, Paul J. Steinhardt
doaj +1 more source
Cosmology Due to Thermodynamics of Apparent Horizon
Annalen der Physik, Volume 537, Issue 11, November 2025.Effective cosmological constant as a function of the Hubble rate H for different entropy parameters b. Figure shows the asymptotic of the effective cosmological constant. At H = 0 the effective cosmological constant vanishes. Abstract This study proposes new entropy of the apparent horizon Sh=(1/β)arctan(βSBH)$S_h=(1/\beta)\arctan (\beta S_{BH ...
S. I. Kruglov
wiley +1 more source
The Berry phase in inflationary cosmology [PDF]
, 2011 We derive an analogue of the Berry phase associated with inflationary cosmological perturbations of a quantum-mechanical origin by obtaining the corresponding wavefunction.
B. Pal +3 more
semanticscholar +1 more source
Inner Magnetospheric and Geomagnetic Responses to Solar Wind Driving During Omega Band Events
Journal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.Abstract Omega bands are mesoscale auroral structures that appear as quasi‐periodic eastward drifting protrusions of the poleward edge of the diffuse aurora. Cribb et al. (2024), https://doi.org/10.1029/2024gl109756 demonstrated that the appearance of omega bands is associated with solar wind driving consistent with stream interaction regions. However,
V. Cribb +6 more
wiley +1 more source
Postinflationary scalar tensor cosmology and inflationary parameters [PDF]
Physical Review D, 2018 19 pages, 2 figures. References added, minor changes.
Maharana, Anshuman, Zavala, Ivonne
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Gravity Modeling of Lunar Lava Tubes: Insights From a Terrestrial Analog
Journal of Geophysical Research: Planets, Volume 130, Issue 11, November 2025.Abstract The exploration of lunar lava tubes can address challenges of human habitation on the Moon by identifying natural shelters against radiation, temperature extremes, and micrometeoroid impacts. This study shows the feasibility of detecting lunar lava tubes with gravimetry using Ape Cave in Washington State, USA, as a terrestrial analog. Ape Cave'
Sarai Montañez Muñoz +4 more
wiley +1 more source
Loop quantum cosmology: from pre-inflationary dynamics to observations [PDF]
, 2015 The Planck collaboration has provided us rich information about the early Universe, and a host of new observational missions will soon shed further light on the ‘anomalies’ that appear to exist on the largest angular scales.
A. Ashtekar, A. Barrau
semanticscholar +1 more source