paper

Constraints on the gravitational potential from DESI DR2 BAO and its implications for the local void scenario

arXiv:2606.02712 · doi:10.3390/universe12080235

Abstract

We constrain the difference in gravitational potential between our location and sources at using datasets at those redshifts. Our motivation is that the Hubble tension might be caused by a local void, as suggested by galaxy number counts. This would increase the redshift through outflow and gravitational redshift (GR). Only the latter is important at high redshift, where a void contributes a fixed additional GR contribution of due to our location on a potential hill. This model has various subtle effects that were not previously considered, including a hotter CMB and reduced BAO scale . We test whether can have the previously expected value of 0.84%, which was based on fitting void parameters to galaxy number counts and local measurements. Combining BBN, CMB, BAO, and CC datasets at , we find that , which rises to when extending our analysis down to . Although the results prefer the standard value of , the best-fitting model with fits the data almost as well as CDM, with . We find that CDM faces a BAO anomaly in the standard parameter space, where different regions are preferred by BAO and non-BAO datasets from . Fixing reduces this to . This suggests that a local void large enough to solve the Hubble tension cannot be ruled out by higher-redshift datasets despite its novel impacts on them.

17 pages, 4 figures, 9 tables. Accepted for publication in Universe in this form

References in corpus (48)