Definitive test of the Rh = ct universe using redshift drift

The redshift drift of objects moving in the Hubble flow has been proposed as a powerful model-independent probe of the underlying cosmology. A measurement of the first- and second-order redshift derivatives appears to be well within the reach of upcoming surveys using as the Extremely Large Telescop...

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Bibliographic Details
Main Author: Melia, Fulvio
Other Authors: Univ Arizona, Dept Phys, Appl Math Program, Dept Astron
Language:en
Published: OXFORD UNIV PRESS 2016
Subjects:
Online Access:http://hdl.handle.net/10150/622477
http://arizona.openrepository.com/arizona/handle/10150/622477
Description
Summary:The redshift drift of objects moving in the Hubble flow has been proposed as a powerful model-independent probe of the underlying cosmology. A measurement of the first- and second-order redshift derivatives appears to be well within the reach of upcoming surveys using as the Extremely Large Telescope high resolution spectrometer (ELT-HIRES) and the Square Kilometer Phase 2 Array (SKA). Here we show that an unambiguous prediction of the R-h = ct cosmology is zero drift at all redshifts, contrasting sharply with all other models in which the expansion rate is variable. For example, multiyear monitoring of sources at redshift z = 5 with the ELT-HIRES is expected to show a velocity shift Delta v = -15 cm s(-1) yr(-1) due to the redshift drift in Planck I > CDM, while Delta v = 0 cm s(-1) yr(-1) in R-h = ct. With an anticipated ELT-HIRES measurement error of +/- 5 cm s(-1) yr(-1) after 5 yr, these upcoming redshift drift measurements might therefore be able to differentiate between R-h = ct and Planck I > CDM at similar to 3 sigma, assuming that any possible source evolution is well understood. Such a result would provide the strongest evidence yet in favour of the R-h = ct cosmology. With a 20-yr baseline, these observations could favour one of these models over the other at better than 5 sigma.