How robust are tension claims in cosmology?

par Lukas Hergt (IJCLab, IN2P3, CNRS)

jeudi 2 avr. 2026, 14:00 → 16:00 Europe/Paris

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Recent combined analyses of CMB, BAO, and supernova data have fuelled claims that LCDM must give way to dynamical dark energy. But how robust are these conclusions? We present a unified Bayesian assessment of model comparison and cross-dataset consistency for LCDM and minimal extensions (curvature, neutrino mass, constant and evolving dark energy), systematically varying the underlying data products — including multiple Planck likelihood implementations, SDSS and DESI BAO measurements, and alternative supernova catalogues. We find that apparent tensions and model preferences depend sensitively on specific data pairings: plausible alternatives can shift inferred tensions by more than 1 sigma and even reverse the preferred model.  Updated Planck processing and revised supernova calibrations further erode several previously reported discrepancies. We conclude that, at present, claims of a required departure from LCDM are premature.