A Kinematic Saturation Bound on Gravitational Acceleration (Pre-print)

We propose a minimal covariant kinematic bound on gravitational acceleration

by restricting the admissible spacetime congruences in strong-field regimes. The con-

struction introduces no new dynamical fields and does not modify Einstein’s field equa-

tions. The bound is formulated directly in terms of the four-acceleration of timelike

congruences and is shown explicitly to yield finite acceleration and curvature in the

Schwarzschild geometry when expressed in Painlev´e–Gullstrand form. The weak-field

limit recovers Newtonian gravity. The result provides a compact and physically trans-

parent constraint on strong gravitational dynamics.