Results 41 to 50 of about 114,518 (203)

H_0 and Odds on Cosmology [PDF]

, 1995
Recent observations by the Hubble Space Telescope of Cepheids in the Virgo cluster imply a Hubble Constant $H_0=80\pm17$\ km/sec/Mpc. We attempt to clarify some issues of interpretation of these results for determining the global cosmological parameters $
Jaffe, A. H.
core   +2 more sources

Hubble’s Constant

Journal of High Energy Physics, Gravitation and Cosmology, 2016
An analytical method to calculate Hubble’s constant [1] is presented. The proposed procedure is an alternative scheme to the red shifts of spectral lines picture, to obtain the value of that constant [2].
openaire   +2 more sources

Existence of Solutions of Semilinear Wave Equations With Time‐Dependent Propagation Speed and Time Derivative Nonlinearity

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT Consider wave equations with time derivative nonlinearity and time‐dependent propagation speed which are generalized versions of the wave equations in the Friedmann–Lemaître–Robertson–Walker (FLRW) spacetime, the de Sitter spacetime and the anti‐de Sitter space time.
Kimitoshi Tsutaya, Yuta Wakasugi
wiley   +1 more source

A simple analysis of halo density profiles using gravitational lensing time delays

, 2006
Gravitational lensing time delays depend upon the Hubble constant and the density distribution of the lensing galaxies. This allows one to either model the lens and estimate the Hubble constant, or to use a prior on the Hubble constant from other studies
B. M. Dobke, Barkana, Biggs, Burud, Burud, Burud, Fabbiano, Fassnacht, Freedman, Gerhard, Guzik, Hjorth, Impey, Jakobsson, Keeton, Kochanek, Kochanek, Kundic, L. J. King, Lovell, Lowenstein, Morgan, Ofek, Patnaik, Refsdal, Rix, Romanowsky, Rusin, Spergel, Treu, Williams, Winn, Witt   +32 more
core   +1 more source

Status and Prospect of Secondary Battery Technologies in Space Applications: Challenges and the Future

Batteries &Supercaps, Volume 9, Issue 5, May 2026.
Lithium‐ion batteries used in space applications are exposed to extreme conditions, including radiation, vacuum, wide temperature fluctuations, and long storage times, all of which accelerate degradation. This review article summarizes the main degradation mechanisms affecting battery performance in space environments, including capacity fade ...
Xunkai Chen, Kelsey B. Hatzell
wiley   +1 more source

JWST Observations Reject Unrecognized Crowding of Cepheid Photometry as an Explanation for the Hubble Tension at 8σ Confidence

The Astrophysical Journal Letters
We present high-definition observations with the James Webb Space Telescope (JWST) of >1000 Cepheids in a geometric anchor of the distance ladder, NGC 4258, and in five hosts of eight Type Ia supernovae, a far greater sample than previous studies with ...
Adam G. Riess, Gagandeep S. Anand, Wenlong Yuan, Stefano Casertano, Andrew Dolphin, Lucas M. Macri, Louise Breuval, Dan Scolnic, Marshall Perrin, Richard I. Anderson   +9 more
doaj   +1 more source

Evidence for dynamical dark energy with an evolving Hubble constant

Astronomy & Astrophysics
Context. Hubble constant tension, together with the recent indications of dynamical dark energy proposed from the Dark Energy Spectroscopic Instrument (DESI) baryon acoustic oscillation (BAO) measurements, poses significant challenges for the standard ...
Wang Yi-Ying, Li Yin-Jie, Fan Yi-Zhong
doaj   +1 more source

Carnegie Hubble Program: A Mid-Infrared Calibration of the Hubble Constant [PDF]

, 2012
Using a mid-infrared calibration of the Cepheid distance scale based on recent observations at 3.6 um with the Spitzer Space Telescope, we have obtained a new, high-accuracy calibration of the Hubble constant. We have established the mid-IR zero point of
Allende-Prieto, Amanullah, Andy Monson, Barry F. Madore, Benedict, Benson, Chris Burns, Dunkley, Fazio, Freedman, Freedman, Hicken, Hu, Jane Rigby, Keisler, Komatsu, Komatsu, Marconi, Mark Seibert, Mehta, Meixner, Monson, Persson, Riess, Riess, Riess, S. Eric Persson, Sandage, Scowcroft, Scowcroft, Sullivan, Suyu, Victoria Scowcroft, Walker, Wendy L. Freedman, Werner   +35 more
core   +3 more sources

The Hubble Constant from SN Refsdal [PDF]

The Astrophysical Journal Letters, 2018
Abstract Hubble Space Telescope observations from 2015 December 11 detected the expected fifth counter-image of supernova (SN) Refsdal at z = 1.49. In this Letter, we compare the time-delay predictions from numerous models with the measured value derived by Kelly et al. from very early data in the light curve of the SN
J. Vega-Ferrero, J. M. Diego, V. Miranda, G. M. Bernstein   +3 more
openaire   +3 more sources

Constraining Electron‐Impact Ionization of O2 Through UV Aurora Observations at Ganymede

Journal of Geophysical Research: Space Physics, Volume 131, Issue 5, May 2026.
Abstract While photoionization rates of Ganymede's O2 ${\mathrm{O}}_{2}$ dominated atmosphere are well constrained, the contribution of electron‐impact ionization is rather uncertain. Previous quantitative estimates have relied on assumptions about densities and energy distributions of precipitating electrons, or on rare spacecraft measurements that ...
Stefan Duling, Joachim Saur, Darrell Strobel, Philippa Molyneux, Jamey R. Szalay, Thomas K. Greathouse   +5 more
wiley   +1 more source