A comparative test of the ΛCDM and R_h = ct cosmologies based on upcoming redshift drift measurements

Abstract A measurement of the redshift drift constitutes a model-independent probe of fundamental cosmology. Several approaches are being considered to make the necessary observations, using i) the Extremely Large Telescope (ELT), ii) the Cosmic Accelerometer, and iii) the differential redshift drift methodology. Our focus in this letter is to assess how these upcoming measurements may be used to compare the predictions of ΛCDM with those of the alternative Friedmann-Lemaître-Robertson-Walker cosmology known as the universe, and several other models, including modified gravity scenarios. The ELT should be able to distinguish between and the other models at better than for after 20 years of monitoring, while the Cosmic Accelerometer may be able to achieve the same result with sources at after only 10 years.