A Substrate Origin of Gravity

This work formulates a gravitational sector derived from Unified Substrate Theory (UST), in which gravity emerges as an effective response of an underlying structured substrate rather than as a fundamental interaction. The substrate is assumed to exhibit discrete scale invariance, implying that its linear gravitational response acquires fixed log-periodic structure across scale.

An explicit, falsifiable prediction is derived for cosmological lensing observables: a small log-periodic modulation of the CMB lensing power spectrum with dimensionless frequencies fixed by the substrate structure and not tuned to data. This prediction is tested against two independent measurements of CMB lensing, Planck 2018 and ACT DR6, using covariance-aware generalized least squares fits in logarithmic space.

Both datasets show their largest improvement relative to a smooth baseline for the same fundamental substrate mode. While the statistical preference is modest and does not constitute a detection, the coherence across independent experiments demonstrates that the proposed gravitational sector is internally consistent, testable, and compatible with current precision cosmology.