The Iglesias Constant: A Geometric Interpretation of Cosmic Acceleration

We introduce a geometric constant $K_i$ modifying the Einstein field equations
through an additional curvature scale. The resulting framework produces
cosmic acceleration without invoking a cosmological constant or exotic
dark energy fluid.

Within the Friedmann–Lemaître–Robertson–Walker metric, the Iglesias constant
generates an effective vacuum contribution that naturally reproduces the
observed expansion history of the Universe. Predictions are compared with the
standard $\Lambda$CDM cosmology and potential observational signatures at
high redshift are discussed