Speaker
Description
The newly released data of DESI has suggested an unexpected dynamical evolution of our Universe that indicates new physics beyond the standard cosmological paradigm of the LCDM.
We reconstructed the H(z) function to get the effective dark-energy equation-of-state parameter w(z) by virtue of the Gaussian Process method using the DESI-BAO + Previous BAO data. We discovered that w(z) exhibits a surprising behavior of crossing -1 from the phantom to quintessence regime along with the cosmic expansion, dubbed as quintom-B scenario. Theoretically, however, such a scenario is one of the most difficult phenomenon that could be explained by the knowledge of traditional field theories, and hence poses new challenges to the current theoretical paradigm. As a demonstration of probing new physics, we further reconstruct the actions for a series of modified gravity theories including f(R), f(T), and f(Q) gravity appropriately by applying the data-driven H(z) function. Our results have delicately illustrated the reasonable interpretations of such a nontrivial dynamic of the Universe from gravitational physics beyond General Relativity.
