Speaker
Description
The Cosmic Distance Duality Relation (CDDR) is a fundamental geometric relation that connects the luminosity distance and the angular diameter distance at a given redshift. It holds in any metric theory of gravity with standard photon propagation and number conservation, and is therefore independent of any specific cosmological model. Since distance measurements form the basis of our understanding of the expansion history, CDDR provides a powerful and robust consistency test between different cosmological probes. In this work, combining the two distance probes - BAO and Type Ia Supernovae - we show that distance duality serves as an anchor bridging the early-late calibration by constraining a specific combination of $r_d-M_b$, in a model-independent fashion. We further demonstrate that, under the assumption of the CDDR, the joint SNIa and BAO analysis imposes stringent, model-independent constraints on the Hubble constant, effectively ruling out a broad class of late-time solutions to the Hubble tension.