CITA@40 Conference

Sound-horizon-agnostic approaches to the Hubble tension and an update on primordial magnetic fields

Not scheduled

20m

McLennan Physical Laboratories (60 St. George St.)

Oral

Speaker

Levon Pogosian (Simon Fraser University)

Description

The Hubble tension points to possible gaps in our understanding of physics around the epoch of recombination. A key aspect of the tension is its sensitivity to the sound horizon at decoupling, r_, whose value depends on the microphysics of recombination. It is therefore highly desirable to obtain empirical constraints on both H_0 and r_ without relying on model-dependent assumptions. I will present recent work that demonstrates how combining baryon acoustic oscillations with CMB lensing enables such sound-horizon-agnostic measurements of the Hubble constant. I will also provide an update on primordial magnetic fields as a potential mechanism for alleviating the Hubble tension.