The Hubble horizon at matter-radiation equality () and the sound horizon at the last scattering surface () provides interesting consistency check for the CDM model and its extensions. It is well known that the reduction of can be compensated by the increase of , while the same is true for the standard rulers . Adding extra radiational component to the early universe can reduce . The addition of early dark energy (EDE), however, tends to increase . We perform - and -based analyses in both the EDE model and the Wess-Zumino Dark Radiation (WZDR) model. In the latter case we find between the - and -based datasets, while in the former case we find . This result suggests that the dark radiation scenario is more consistent in the fit of the two standard rulers ( and ). As a forecast analyses, we fit the two models with a mock prior derived from \emph{Planck} best-fit CDM model. Compared with the best-fit in baseline CDM model, we find for WZDR model and for EDE model.

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