Entropy Density Ceiling Implied by a Finite Maximum Density

This paper examines what maximum entropy per unit volume follows when both the Bekenstein bound and a finite maximum density are imposed. The calculation is performed in a frame with a finite maximum density, the neutron-branch value rho_A = 9.718e+57 kg per cubic metre, with the electron branch at 2.874e+51 kg per cubic metre for comparison. Headline results include a bounce temperature of 3.278e+22 K, a Landauer cost at that temperature of 3.137e-01 J per bit against 2.871e-21 J per bit at 300 K, a Bekenstein allowance of 1.049e+94 bits for the stated centimetre reference region, and a Margolus-Levitin rate of 2.209e+103 per second for the same region. The entropy density ceiling grows with radius under the bekenstein form, so a single universal entropy density cannot be quoted without stating the region size. All numbers are computed from the stated assumptions in the accompanying script; the study is simulated and computed, not measured.