The Crustal Shear Modulus Profile, Shear Wave Speeds, and the Absence of a Framework Shear Bound

The shear modulus of neutron-star crust matter determines how the crust responds to every stress applied to it, from spin-down to magnetic evolution to oscillations. This study computes the modulus profile from the Coulomb-lattice expression across the full crust density range and compares the resulting stresses with the largest scale the torsion framework supplies. The modulus rises from 2.7e+26 Pa at a density of 1e14 kg per cubic metre to 3.9e+29 Pa near the crust base, and the corresponding shear wave speed rises from 1.66e+06 to 1.74e+06 m per second. The largest elastic stress the crust can carry, about 3.9e+28 Pa, is smaller than the stress scale associated with the Aldred density bound by a factor of 4.5e-47. The framework therefore supplies no shear bound at crust conditions: it offers a density ceiling forty orders of magnitude above crust densities and no finite shear-failure density within the crust at all, a negative result stated plainly. Crust elasticity is a Coulomb-lattice problem end to end. This study is simulated and computed from stated assumptions; it is not a measurement.