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 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.Amherst CollegeThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu