$\hat{I}{›}_{\mathrm{s}}$CDM model: A promising scenario for alleviation of cosmological tensions

Abstract

We present a comprehensive analysis of the $\hat{I}{›}_{\mathrm{s}}$CDM model, which explores the recent conjecture suggesting a rapid transition of the Universe from anti-de Sitter vacua to de Sitter vacua (viz., the cosmological constant switches sign from negative to positive) at redshift $z_{†}\sim 2$, inspired by the graduated dark energy (gDE) model. Our analysis shows that, predicting $z_{†}\approx 1.7$, $\hat{I}{›}_{\mathrm{s}}$CDM simultaneously addresses the major cosmological tensions of the standard $\hat{I}›$CDM model, viz., the Hubble constant $H_0$, the Type Ia Supernovae absolute magnitude $M_{\mathrm{B}}$, and the growth parameter $S_8$ tensions, along with other less significant tensions such as the BAO Lyman-$\hat{I}\pm$ discrepancy.

7 pages, 3 figures, 1 table, and Supplemental material (7 pages, 8 figures, 2 tables)