Speaker
Description
We present a unified analysis of the late-time cosmic expansion by bridging model-independent cosmography with modified gravity, using the latest DESI DR2 BAO data. A comparative study of Taylor, Padé, and Chebyshev expansions shows that while Taylor breaks down beyond low redshift, Padé approximants, especially (2,1), deliver stable, high-redshift reconstructions and are strongly preferred by information criteria, closely tracking LCDM. Leveraging this, we embed the Padé (2,1) framework within f(T) gravity and contrast it with direct dynamical solutions of the modified Friedmann equations. A comprehensive MCMC analysis with DESI DR2 and complementary probes reveals remarkable agreement between the two approaches, with both outperforming LCDM. Our results establish Padé cosmography as a powerful and reliable interface between data-driven reconstruction and fundamental gravity.
