This record presents version v18b+ of the Geometric Relay Theory (GRT), a theoretical framework developed by Olivier Larquey and built on Olivier Minazzoli’s Entangled Relativity action Lₘ²/R. GRT interprets the non-minimal matter–geometry coupling of Entangled Relativity through an effective scalar relay σ mediating between matter content and geometry. This version gathers several connected developments: Wald entropy for Lₘ²/R, informational selection of Entangled Relativity, variation of effective constants, a modified Maxwell sector with Q = 2Lₘ/R, a complete Kaluza–Klein derivation, radion stabilization, an effective Yukawa coupling of the relay, and a cyclic relay cosmology with horizon–bounce duality. The new v18b+ contribution is a parametrized observational test for M87*. The model predicts an effective Maxwell-Q correction in strongly magnetized plasma near the black-hole environment, with δQ/Q in the range 5%, 80% and a corresponding polarization-angle residual δχ at 230 GHz in the range 3°, 30°, depending on plasma conditions. The discriminating signature is not merely a non-zero polarization deviation, but a structured residual correlated with the local magnetic state of the plasma, especially low plasma beta regions, inner MAD zones, and jet-base environments. The document also lists testable predictions and failure criteria, including signatures related to magnetars, M87* polarization, compact-object quasi-normal modes, rare B transitions, and cosmological sectors. The status is theoretical and exploratory: the framework is presented as a falsifiable research programme, not as an experimentally validated theory. Further work requires GRMHD simulations including the variable Maxwell-Q sector and polarimetric ray-tracing comparisons with EHT data.
Olivier Lane-larquey (Sat,) studied this question.