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SUMMARY:Hubble tension and statistical processing of astronomical data
DTSTART;VALUE=DATE-TIME:20220928T143000Z
DTEND;VALUE=DATE-TIME:20220928T163000Z
DTSTAMP;VALUE=DATE-TIME:20220924T220520Z
UID:indico-event-1198612@indico.cern.ch
DESCRIPTION:Many of you have either processed experimental data yourself
or used the results of processing done by someone else. I want to demonst
rate that processing\, even standard processing\, is not at all a simple
procedure and can be a source of errors\, in particular those caused by bi
as. This is what can explain Hubble tension\, i.e. a statistically signifi
cant difference in the values of the Hubble constant obtained as a result
of processing observations in the early and late Universe.This report is
based on my paper BIAS OF THE HUBBLE CONSTANT VALUE CAUSED BY ERRORS IN G
ALACTIC DISTANCE INDICATORS (arxiv 2109.09645\, Ukrainian Journal of Phy
sics\, Vol. 66 No. 11 (2021))The bias in the determination of the Hubble
parameter and the Hubble constant in the modern Universe is discussed. It
could appear due to statistical processing of data on galaxies redshifts
and estimated distances based on some statistical relations with limited
accuracy. This causes a number of effects leading to either underestimatio
n or overestimation of the Hubble parameter when using any methods of sta
tistical processing\, primarily the least squares method (LSM). The value
of the Hubble constant is underestimated when processing a whole sample\;
when the sample is constrained by distance\, especially when constrained
from above\, it is significantly overestimated due to data selection. The
bias significantly exceeds the values of the error the Hubble constant ca
lculated by the LSM formulae.These effects are demonstrated both analytica
lly and using Monte Carlo simulations\, which introduce deviations in both
velocities and estimated distances to the original dataset described by
the Hubble law. The characteristics of the deviations are similar to real
observations. Errors in estimated distances are up to 20%. They lead to th
e fact that when processing the same mock sample using LSM\, it is possib
le to obtain an estimate of the Hubble constant from 96% of the true value
when processing the entire sample to 110% when processing the subsample
with distances limited from above.The impact of these effects can lead to
a bias in the Hubble constant obtained from real data and an overestimatio
n of the accuracy of determining this value. This may call into question
the accuracy of determining the Hubble constant and significantly reduce t
he tension between the values obtained from the observations in the early
and modern Universe\, which were actively discussed during the last year.
\n\nhttps://indico.cern.ch/event/1198612/
LOCATION:CERN 4/3-006 - TH Conference Room
URL:https://indico.cern.ch/event/1198612/
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