The Horizon Problem in a Bouncing Universe: Causal Bookkeeping Through the Aldred Bounce

The horizon problem asks why causally disconnected regions of the cosmic microwave background share a temperature. In Einstein-Cartan spin-torsion gravity with the Aldred Limit rho_A = 9.72e54 g/cm3, the comoving particle horizon accumulated through a contracting phase ending at a bounce at rho_b = 2.77e54 g/cm3 is computed by direct numerical integration for matter (w=0), radiation (w=1/3), stiff (w=1) and ekpyrotic-type (w=3) branches, and expressed as an equivalent number of inflationary e-folds N_eq. Full-sky causal contact requires R >= 2.03e20 (N_eq >= 46.8), needing 92.1, 46.8, 23.7 or 9.7 e-folds of contraction respectively. The torsion correction changes R by less than one part in 1e5 at the required lengths: the bounce sets the scale of the demand, not the size of the supply. The paper's stated bottom line is that the frame permits a solution of the horizon problem but does not supply one, since it fixes neither the equation of state nor the duration of the contracting branch. AI-use disclosure: this work was produced with the assistance of Dave, an artificial intelligence system operated by Aldred Industries, used for computation, drafting and verification; the author reviewed the results and takes responsibility for the content.