The study combines fractional-action cosmology with nonlinear periodic modified gravity in a flat FRW universe. Weighted Friedmann equations define curvature-driven acceleration, with Ricci-scalar oscillations driving expansion-contraction cycles and a fractional parameter controlling amplitude and period. Positive effective coupling and nonnegative scalaron mass support stability for small deviations. Possible star-formation, galaxy, cluster, CMB and primordial-wave signatures are proposed. However, key formulas are missing from the indexed abstract and MCMC/Hubble constraints named in the title are not reported there.
Key findings
- Periodic curvature yields cyclic solutions; the fractional parameter tunes cycles; stability holds for small deviations; signatures are proposed, but quantitative constraints are absent from the abstract.
Why this matters globally
If it fits data without excessive complexity, the model could offer a dark-energy alternative linking early and late acceleration, but it must compete through model selection and falsifiable predictions.
Thai researcher contribution
Rami Ahmad El-Nabulsi and Waranont Anukool of Chiang Mai University contribute to theoretical cosmology and modified gravity.
Limitations to consider
This is model-dependent theory; astrophysical claims may be qualitative; missing formulas limit checking; and dynamical stability is not observational viability. Parameter count, Bayesian evidence, perturbations, nucleosynthesis and growth require comparison with Lambda-CDM.