The Constrainton Causal Relaxation of Boundary-Induced Configuration Space Updates

This paper identifies a causal gap in how time-dependent boundaries are treated in effective electromagnetic and cavity formalisms. While fundamental physics enforces locality and finite propagation speed, commonly used boundary descriptions update the availability of field configurations instantaneously when a boundary moves, which is formally acausal if that availability has physical consequences. The paper argues that if configuration space availability is physically meaningful—as evidenced by which field modes can or cannot exist—then changes to it must relax locally over time. It proposes the Constrainton as the minimal, non-electromagnetic constraint-field excitation representing this finite-rate relaxation of the vacuum’s configuration space following non-adiabatic boundary motion, without modifying established physics. A clear, falsifiable prediction is given: a temporary “temporal configuration shadow” in which specific field modes remain unavailable even after electromagnetic signals from the moving boundary have arrived.