Unraveling the Hubble Tension: Beyond Early Dark Energy

The Hubble Tension problem, which refers to the disagreement between various measures of the Hubble parameter, is a deep mystery in cosmology. While much effort has been focused on understanding dark energy to resolve this tension, a recent article outlines seven reasons to suspect that dark energy alone may not be enough. These reasons include discrepancies between cosmic and stellar ages, Baryon Acoustic Oscillation and Cosmic Microwave Background observations, model-independent measures of the Hubble parameter, variations in the Hubble parameter with redshift, the Integrated Sachs-Wolfe effect, and constraints on matter density. Solving the Hubble Tension problem may require a combination of adjustments or a radical new understanding of physics.