Observational constraints on the modified cosmology inspired by string T-duality

Abstract

We explore the cosmological consequences of a modified cosmology inspired by string T-duality. We incorporate the zero-point length correction, $l_0$, into the gravitational potential and derive the modified Friedmann equations via thermodynamic approach at the apparent horizon of a Friedmann-Robertson-Walker (FRW) universe. The resulting framework introduces a dimensionless coupling parameter $\beta \sim l_0^2{H}_0^2$ quantifying deviations from the standard $\Lambda$CDM model. Using Bayesian inference with \textsc{Cobaya} and MCMC sampling, we constrain the model parameter against late-time observations, including PantheonPlus and Union3 Type~Ia supernovae, cosmic chronometers, DESI~DR2 BAO measurements, and Amati-calibrated GRBs. The joint analysis yields an upper bound $\beta \lesssim \mathcal{O}(10^{-3})$ (68\% C.L.), implying that departures from $\Lambda$CDM are extremely small within current precision. Model comparison through the Akaike Information Criterion shows that the $\Lambda$CDM and T-duality models provide statistically equivalent fits to the data, exhibiting only a marginal preference for $\Lambda$CDM. These results provide the first quantitative observational constraints on string T-duality inspired modified cosmology and underscore the potential of future high-precision surveys to test quantum-gravity induced corrections in a late-time universe.

10 pages, 2 figures, 2 tables. Comments are welcome

References in corpus (11)

• Thermodynamic Behavior of Friedmann Equation at Apparent Horizon of FRW Universe
• Unified First Law and Thermodynamics of Apparent Horizon in FRW Universe
• Thermodynamic route to Field equations in Lanczos-Lovelock Gravity
• Thermodynamical Properties of Apparent Horizon in Warped DGP Braneworld
• Eppur è piatto? The cosmic chronometer take on spatial curvature and cosmic concordance
• Deep Connection Between Thermodynamics and Gravity in Gauss-Bonnet Braneworld
• Modified cosmology from extended entropy with varying exponent
• Modified cosmology through spacetime thermodynamics and Barrow horizon entropy
• Grin of the Cheshire cat: Entropy density of spacetime as a relic from quantum gravity
• Hints Beyond $\Lambda$CDM from Barrow and Tsallis Holographic Dark Energy with GO cutoff
• Probing dynamical embeddings in a five-dimensional spacetime in light of DESI BAO

Cited by in corpus (1)

• Breaking Free from the Swampland of Impossible Universes through the DESI Portal