6–31 juil. 2026
Galileo Galilei Institute
Fuseau horaire Europe/Paris

Model Independent Reconstruction of the Cosmological Evolution at Low Redshifts and Possible Theoretical Explanation

28 juil. 2026, 14:00
1h 15m
Galileo Galilei Institute

Galileo Galilei Institute

Orateur

Anjan Ananda Sen (Jamia Millia Islamia Central University)

Description

We investigate the late-time expansion history of the Universe using a model-independent reconstruction of
cosmological distances based on the latest DESI-DR2 BAO measurements and the DES Dovekie Type Ia
Supernova compilation. We reconstruct the expansion rate over the full redshift range probed by the data and
compare it with the prediction of the Planck 2018 ΛCDM model. We identify a localized deviation in the
reconstructed expansion history at intermediate redshifts. We show that this feature persists under variations
of the reconstruction methodology, dataset composition, sound-horizon calibration, and H0 priors. The
persistence of the deviation under these tests suggests that it is a robust feature preferred by current low-redshift
distance measurements and may not be fully explained by modifications affecting only early-Universe physics. We
subsequently model this deviation using a RG-Flow like Logistic Evolution that gives a statistically better fit than other
most studied cosmological evolution.

Documents de présentation

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