Cosmographic constraints on a Gödel-type rotating universe

Abstract We investigate the possibility of global cosmic rotation using a Gödel-type rotating cosmological model, constrained through a cosmographic analysis of Type Ia supernovae (SNIa) from the Pantheon+ dataset. Employing a Taylor-expanded apparent magnitude–redshift relation derived via the Kristian-Sachs formalism, we analyze low-redshift SNIa data across five redshift bins (up to Z ≤ 0.5). Our results reveal a mild but consistent preference for cosmic rotation, with the dimensionless rotation parameter Ω 0 peaking at 0.29 +0.21 -0.15 for Z ≤ 0.2, and a broadly aligned anisotropy axis centered around equatorial coordinates (243°, -49°). The inferred Hubble constant h 0 ≈ 0.73 remains stable across all bins, while the deceleration parameter q 0 trends from near-zero to mildly negative values with increasing redshift. Model comparison using the Akaike Information Criterion (AIC) indicates a statistically significant preference for the rotating model over the standard ΛCDM cosmology at intermediate redshifts. A new result presented in the current work is the derivation of “ m-Z ” relation up to 𝒪( Z 2 ) using the Kristian-Sachs expansion. Parameter estimates thus obtained from the extended cosmographic expansion result in weaker estimates with broad posteriors. These results highlight the need for beyond-cosmographic approaches to robustly assess the possibility of cosmic rotation and its influence on late-time expansion history of the universe.