Time:  10h30 Tuesday the 2nd of December 2025

Title: An inhomogeneous universe as a possible interpretation of DESI BAO result

Speaker: Prof. Toshi Futamase (Tohoku University)

Venue:  SC427, Science Building 3, NYCU

Abstract:

In 2024, DESI (Dark Energy Spectroscopic Instrument) reported the time variation of the Hubble parameter based on BAO (Baryon Acoustic Oscillation) observations, showing that it contradicts the predictions of standard cosmology. One interpretation of these discrepancies is to introduce an appropriate time variation to dark energy without changing the cosmological model. We do not take this point of view, but take a completely different point of view that is based on observations from infrared galaxy surveys, indicating that the Milky Way galaxy is located in a low-density region on a 300 Mpc scale.

In this talk, I will begin with a brief explanation of DESI, BAO, and the Hubble tension, and then consider the effect of inhomogeneous distribution of matter on the cosmological expansion. I will explain how this effect allows us to interpret the DESI results and simultaneously explain the Hubble tension.