Cosmographic constraints from late-time probes including fast radio bursts

In this study, we use late-time probes, such as well-localized fast radio bursts (FRBs), baryon acoustic oscillations (BAO), supernovae (SNe), and cosmic chronometers (CC) to constrain cosmological parameters through a model-independent cosmographic approach. By integrating FRB data with BAO from DESI DR2, SNe, and CC, we derive constraints on the Hubble constant (H 0), the deceleration parameter (q 0), and the jerk parameter (j 0), using Markov Chain Monte Carlo (MCMC) analysis for parameter estimation. The cosmographic approach with FRBs alone provides H 0 = 66.35+4.13-5.04, km, s-1, Mpc-1, q 0 = -0.33+0.21-0.15, and j 0 = 0.83+0.57-0.67, corresponding to a precision of about 6% for the Hubble constant and showing consistency with the Λ CDM expectation. The DESI+CMB dataset yields H 0 = 65.59+1.25-1.24, km, s-1, Mpc-1, q 0 = -0.29+0.07-0.08, and j 0 = 0.58+0.03-0.04, providing a about 2% precision on H 0 and may suggest a possible tension in the late-time kinematic sector relative to the Λ CDM expectation when BAO measurements are calibrated with a Planck-inferred sound horizon. Combining the FRB, SNe, DESI+CMB, and CC datasets further tightens the constraints to H 0 = 68.03+0.53-0.52, km, s-1, Mpc-1, q 0 = -0.41 plus or minus 0.02, and j 0 = 0.55 plus or minus 0.02, with the jerk parameter remaining lower than j 0 = 1 at the 1σ confidence level. These findings hint at a possible late-time kinematic tension, as indicated by the inferred value of the jerk parameter, which is primarily driven by the DESI+CMB dataset under standard early-Universe assumptions for the sound horizon.