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arXiv · 2603.16852

Beyond $\Lambda$CDM with a Logistic RG-like Flow of the Low Redshift Cosmic Evolution

Shibendu Gupta Choudhury·Anjan A Sen
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Abstract

Recent observations hint at possible late-time deviations from $\Lambda$CDM. We introduce a minimal phenomenological framework in which the total equation of state $w_{\rm T}(z)$ follows a logistic evolution motivated by renormalization-group-like flow between cosmological fixed points. Using DESI-DR2 BAO, DES supernova data, and CMB distance priors, we find that this parametrization provides an improved description of the expansion history relative to $\Lambda$CDM. The reconstructed evolution, though model specific, also shows statistically strong low-redshift deviations from $\Lambda$CDM.

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Shibendu Gupta Choudhury, Anjan A Sen. 2026-03-17. Beyond $\Lambda$CDM with a Logistic RG-like Flow of the Low Redshift Cosmic Evolution. https://doi.org/10.1103/js6x-6lvq

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