2026/01/15 by Santosh V. Lohakare, S. K. Maurya, Aaisha Al Qassabi +1 · 2 citations
Physics and Astronomy · #Cosmological perturbation theory #Cosmology #Cosmology and Gravitation Theories #Dark energy #Friedmann–Lemaître–Robertson–Walker metric #Galaxies: Formation, Evolution, Phenomena #Hubble volume #Hubble's law #Markov chain Monte Carlo #Noncommutative and Quantum Gravity Theories #Redshift #Scalar (mathematics) #Shape of the universe
paper · pdf · doi:10.1088/1475-7516/2026/07/024
openalex publication_date 2026/07/01 · openalex created_date 2026/07/09 · openalex updated_date 2026/07/30
Abstract We explore the cosmological dynamics of a teleparallel Gauss-Bonnet gravity model defined by the torsion scalar T and the torsion-based Gauss-Bonnet invariant T 𝒢 , deriving modified Friedmann equations for a flat FLRW Universe and corresponding linear scalar perturbation equations. Using a numerical approach, we solve these equations for pressureless matter, predicting the redshift evolution of the Hubble parameter H ( z ). Using a Bayesian Markov chain Monte Carlo analysis based on late-time observations from Cosmic Chronometers, Pantheon + without SH0ES, and DESI BAO Data Release 1 and Data Release 2, we constrain the model parameters and show that this class of f ( T , T 𝒢 ) cosmologies can mimic an effective dark-energy component without introducing an explicit cosmological constant. We further examine the scalar perturbation sector of the posterior-supported cosmological branch and find that the solutions considered in this work remain well-behaved within the adopted perturbative treatment. The model yields a present-day effective equation-of-state parameter in the range ω eff ( z = 0) ≈ -0.664 to -0.693, consistent with late-time observations, and shifts the inferred value of H 0 toward 69–71.5 km s -1 Mpc -1 , suggesting a partial alleviation, though not a complete resolution, of the Hubble tension.