Speaker
Description
"Symmetric teleparallel gravity provides a geometrically distinct route to extending General Relativity, but a viable cosmological model must remain consistent across both cosmological and local gravitational regimes. We investigate an analytic infrared-completed f(Q) model designed as a controlled deformation of the symmetric teleparallel equivalent of General Relativity (STEGR).
The cosmological branch is calibrated by E(0)=1 and the present deceleration parameter q0, with no additional hidden background-level fitting freedom once the cosmological parameters are specified. We examine its viability through branch continuity, fQ>0, background regularity, present acceleration, and recovery of the matter-dominated regime. The cosmological evolution is further characterized using the jerk hierarchy and the Om(z) diagnostic and benchmarked against cosmic-chronometer H(z) measurements together with supernova- and BAO-style distance residuals relative to ΛCDM.
We then independently examine the local weak-field sector. The model recovers the Newtonian limit at O(v^2), while the resulting leading PPN envelope remains below the tested Cassini/Shapiro scale for the fiducial branch. This provides a reproducible framework for studying how modified gravitational dynamics can connect cosmological evolution with controlled recovery of General Relativity at local scales [1].
[1] D. Kaykı, L. Yıldız, and E. Güdekli, “Cosmographic Admissibility and Weak-Field Recovery in an Analytic Infrared-Completed f(Q) Gravity Model,” International Journal of Geometric Methods in Modern Physics, 2650316 (2026). https://doi.org/10.1142/S0219887826503160"