Spin-Sourced Torsion in Pulsars and Magnetars: A Null Result with Its Margin Printed

In Einstein-Cartan gravity, torsion is sourced by the intrinsic spin density of matter. In the frame defined by the Aldred Limit, rho_A = 9.72e54 g/cm^3, this paper computes the spin-density and timing channel for a canonical pulsar, a millisecond pulsar, and a magnetar (central density 1.0e15 g/cm^3), for full spin alignment (unphysical, used as an upper bound) and for realistic Pauli polarisation f = |mu_n| B / E_F. The fully aligned core spin density is 3.15e11 erg s/cm^3, but alignment multiplies the quadratic torsion term by only a factor of two: the fractional correction is 2.06e-40 at full alignment and 1.03e-40 at realistic polarisation, roughly forty orders of magnitude below unity. Over a ten-year timing baseline the spin-down channel accumulates at most 7.5e-34 s against achieved residuals of 1e-2 to 1e-7 s (a shortfall of about thirty-two orders of magnitude); a generous linear precession bound remains 2.4-4.7 orders below achieved precision at full alignment and 8.7-14.1 orders below it at realistic polarisation. Detection would require timing residuals of order 1e-39 s or a central density of 1.45e47 g/cm^3. The channel is closed; the paper is a negative result with its margin printed. AI-use disclosure: this work was prepared with the assistance of Dave, an artificial intelligence system built and operated by Aldred Industries. The computations were performed by a saved, deposited script (compute.py); the author reviewed the results and takes responsibility for the contents.