Is local H0 at odds with dark energy EFT?

Local H-0 determinations currently fall in a window between H-0 similar to 70 km/s/Mpc (TRGB) and H-0 similar to 76 km/s/Mpc (Tully-Fisher). In contrast, BAO data calibrated in an early Lambda CDM universe are largely consistent with Planck-Lambda CDM, H-0 similar to 67.5 km/s/Mpc. Employing a generic two parameter family of evolving equations of state (EoS) for dark energy (DE) w(DE)(z) and mock BAO data, we demonstrate that if i) w(DE)(z = 0) < -1 and ii) integrated DE density less than Lambda CDM, then H-0 increases. EoS that violate these conditions at best lead to modest H-0 increases within 1 sigma. Tellingly, Quintessence and K-essence satisfy neither condition, whereas coupled Quintessence can only satisfy ii). Beyond these seminal DE Effective Field Theories (EFTs), we turn to explicit examples. Working model agnostically in an expansion in powers of redshift z, we show that Brans-Dicke/f(R) and Kinetic Gravity Braiding models within the Horndeski class can lead to marginal and modest increases in H-0, respectively. We confirm that as far as increasing H-0 is concerned, no DE EFT model can outperform the phenomenological two parameter family of the DE models. Evidently, the late universe may no longer be large enough to accommodate H-0, BAO and DE described by EFT.

Automated summary

Local determinations of H-0 fall within a range of approximately 70 km/s/Mpc (TRGB) to 76 km/s/Mpc (Tully-Fisher). In contrast, BAO data calibrated in an early Lambda CDM universe indicate H-0 of approximately 67.5 km/s/Mpc, consistent with Planck-Lambda CDM. By studying different dark energy equations of state and mock BAO data, it is shown that H-0 can increase under certain conditions. Specific models such as Brans-Dicke/f(R) and Kinetic Gravity Braiding within the Horndeski class can also lead to modest increases in H-0.