The Kerr Constant from Artian Geometry and Quantum Traction Theory

The Kerr constant as a material rail, not a fitted table entry Concept DOI: 10.5281/zenodo.20539673 Author: Ali Attar Website: quantumtraction.org Main book anchor: Quantum Traction Theory: Main Book v10.01 This paper develops the QTT source rail for the optical Kerr constant. The classical quantity is normally handled as a material-dependent empirical coefficient; here the aim is to separate the Artian field-response skeleton from the material rail that must be supplied by the molecule or medium. The laboratory row is the induced birefringence law \[ \Delta n = K\lambda E^2, \] while the QTT decomposition reads the measured coefficient through a source rail and a material access rail, schematically \[ K_{\mathrm{mat}}^{\mathrm{QTT}} =K_{\mathrm{src}}^{\mathrm{Artian}}\,\mathcal M_{\mathrm{mat}}^{\mathrm{access}}. \] The purpose is not to hide material physics inside a symbol, but to give a controlled place for polarizability, density, wavelength, and molecular symmetry to enter without turning the universal source law into a fit. Core labels: Σ-KERR-SOURCE-RAIL, Σ-MATERIAL-ACCESS-RAIL, Σ-NONLINEAR-OPTICS-QTT-CORRIDOR.