APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Toshifumi Futamase (Tohoku University)
Title: Possible interpretation of DESI BAO result
Date (JST): Thu, Aug 27, 2026, 13:30 - 15:00
Place: Seminar Room A
Abstract: Observations of Baryon Acoustic Oscillations (BAO) by DESI (Dark Energy Spectroscopic Instrument) revealed a time evolution of the Hubble parameter that is inconsistent with the standard cosmological model. This discrepancy is interpreted as a potential sign of the time-varying nature of dark energy. However, based on the existence of a low-density region on the 300 Mpc scale—revealed by infrared galaxy surveys— we propose an alternative interpretation.

In this talk, we first discuss the impact of large-scale matter inhomogeneities on cosmic expansion, and then explain the mechanism by which these inhomogeneities can naturally account for the DESI results and supernova m-z observational data.