Description
I will discuss a model-independent reconstruction of the late-time expansion history of the Universe based on characteristic redshifts extracted from low-redshift distance data. Using DESI DR2 BAO and DES supernova observations, we identify seven anchor redshifts that allow a direct determination of H(z) without assuming any specific dark energy parametrization. The reconstruction reveals the strongest departures from the Planck 2018 LambdaCDM prediction at low redshift, especially near z ~ 0.35-0.55, whereas agreement is mostly recovered for z > 0.7. I will further show that using the Raychaudhuri equation as a physics-based prior leads to tighter constraints on the dark energy pressure and improves the consistency of the reconstruction. In this framework, the results closely reproduce CPL-like dark energy behaviour. Together, these results suggest that characteristic redshifts, combined with physics-informed kinematic reconstruction, provide a robust way to probe possible new physics in the late-time Universe. Based on: Rept.Prog.Phys. 88 (2025) 9, 098401; arXiv: 2510.09602