scholarly journals Reference frame dependence of the local measurement of the Hubble constant

2020 ◽  
Vol 101 (10) ◽  
Author(s):  
Zhe Chang ◽  
Qing-Hua Zhu
Keyword(s):  
Reference Frame ◽  
Hubble Constant ◽  
Local Measurement ◽  
Frame Dependence

scholarly journals Distant foreground and the Planck-derived Hubble constant

2020 ◽  
Vol 492 (4) ◽  
pp. 5052-5056 ◽  
Author(s):  
V N Yershov ◽  
A A Raikov ◽  
N Yu Lovyagin ◽  
N P M Kuin ◽  
E A Popova
Keyword(s):  
Hubble Constant ◽  
Temperature Fluctuations ◽  
Coarse Grain ◽  
Model Parameters ◽  
Local Measurement ◽  
Microwave Background ◽  
Random Samples ◽  
Local Measurements ◽  
Grain Dust ◽  
Cmb Temperature

ABSTRACT It is possible to reduce the discrepancy between the local measurement of the cosmological parameter H0 and the value derived from the Planck measurements of the cosmic microwave background (CMB) by considering contamination of the CMB by emission from some medium around distant extragalactic sources, such as extremely cold coarse-grain dust. Though being distant, such a medium would still be in the foreground with respect to the CMB, and, as any other foreground, it would alter the CMB power spectrum. This could contribute to the dispersion of CMB temperature fluctuations. By generating a few random samples of CMB with different dispersions, we have checked that the increased dispersion leads to a smaller estimated value of H0, the rest of the cosmological model parameters remaining fixed. This might explain the reduced value of the Planck-derived parameter H0 with respect to the local measurements. The signature of the distant foreground in the CMB traced by supernovae (SNe) was previously reported by the authors of this paper – we found a correlation between the SN redshifts, zSN, and CMB temperature fluctuations at the SNe locations, TSN. Here we have used the slopes of the regression lines $T_{\rm SN}\, /\, z_{\rm SN}$ corresponding to different Planck wavebands in order to estimate the possible temperature of the distant extragalactic medium, which turns out to be very low, about 5 K. The most likely ingredient of this medium is coarse-grain (grey) dust, which is known to be almost undetectable, except for the effect of dimming remote extragalactic sources.

scholarly journals Haptic mental rotation revisited: multiple reference frame dependence

2009 ◽  
Vol 130 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Robert Volcic ◽  
Maarten W.A. Wijntjes ◽  
Astrid M.L. Kappers
Keyword(s):  
Mental Rotation ◽  
Reference Frame ◽  
Frame Dependence ◽  
Multiple Reference

scholarly journals Dark Energy with Phantom Crossing and the H0 Tension

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 404
Author(s):  
Eleonora Di Valentino ◽  
Ankan Mukherjee ◽  
Anjan A. Sen
Keyword(s):  
Dark Energy ◽  
Confidence Level ◽  
Hubble Constant ◽  
Acoustic Oscillation ◽  
Energy Sector ◽  
Local Measurement ◽  
Microwave Background ◽  
Perfect Agreement ◽  
Cosmological Observations ◽  
Phantom Crossing

We investigate the possibility of phantom crossing in the dark energy sector and the solution for the Hubble tension between early and late universe observations. We use robust combinations of different cosmological observations, namely the Cosmic Microwave Background (CMB), local measurement of Hubble constant (H0), Baryon Acoustic Oscillation (BAO) and SnIa for this purpose. For a combination of CMB+BAO data that is related to early universe physics, phantom crossing in the dark energy sector was confirmed at a 95% confidence level and we obtained the constraint H0=71.0−3.8+2.9 km/s/Mpc at a 68% confidence level, which is in perfect agreement with the local measurement by Riess et al. We show that constraints from different combinations of data are consistent with each other and all of them are consistent with phantom crossing in the dark energy sector. For the combination of all data considered, we obtained the constraint H0=70.25±0.78 km/s/Mpc at a 68% confidence level and the phantom crossing happening at the scale factor am=0.851−0.031+0.048 at a 68% confidence level.

Practical Realization of a Reference System for Earth Dynamics by Satellite Methods

1975 ◽  
Vol 26 ◽  
pp. 341-380 ◽  
Author(s):  
R. J. Anderle ◽  
M. C. Tanenbaum
Keyword(s):  
Reference Frame ◽  
Polar Motion ◽  
Pole Position ◽  
Control Points ◽  
Significant Information ◽  
Crustal Motion ◽  
Average Reference ◽  
Future Data ◽  
Existing Data

AbstractObservations of artificial earth satellites provide a means of establishing an.origin, orientation, scale and control points for a coordinate system. Neither existing data nor future data are likely to provide significant information on the .001 angle between the axis of angular momentum and axis of rotation. Existing data have provided data to about .01 accuracy on the pole position and to possibly a meter on the origin of the system and for control points. The longitude origin is essentially arbitrary. While these accuracies permit acquisition of useful data on tides and polar motion through dynamio analyses, they are inadequate for determination of crustal motion or significant improvement in polar motion. The limitations arise from gravity, drag and radiation forces on the satellites as well as from instrument errors. Improvements in laser equipment and the launch of the dense LAGEOS satellite in an orbit high enough to suppress significant gravity and drag errors will permit determination of crustal motion and more accurate, higher frequency, polar motion. However, the reference frame for the results is likely to be an average reference frame defined by the observing stations, resulting in significant corrections to be determined for effects of changes in station configuration and data losses.

How Do Task Instructions Alter the Spatial Reference Frame of Scene-Based Processing?

2011 ◽  
Author(s):  
Mark Mills ◽  
Stefan Van Der Stigchel ◽  
Andrew Hollingworth ◽  
Michael D. Dodd
Keyword(s):  
Reference Frame ◽  
Spatial Reference ◽  
Task Instructions ◽  
Spatial Reference Frame
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