Stress-momentum geometry and the stability of charged particle dynamics

The classical dynamics of charged particles remains conceptually incomplete due to long-standing pathologies of radiation reaction, including runaway solutions, pre-acceleration, and ambiguities associated with uniformly accelerated motion. These difficulties arise from enforcing energy-momentum conservation at the level of point trajectories while discarding the near-field stress-energy generated by the charge itself. Here we present a covariant stress-momentum formulation in which a localized charged state is represented by a finite world-tube supporting internal stress-momentum degrees of freedom. Applying exact conservation laws to this region yields a closed dynamical system in which radiation reaction emerges from stress-momentum transport across the tube boundary together with reversible exchange with a near-field momentum reservoir. Retaining the lowest internal moment produces a causal, well-posed evolution free of runaway and pre-accelerated solutions, while reducing to the Landau-Lifshitz equation in the appropriate limit. The framework provides a transparent resolution of uniform (hyperbolic) acceleration, in which radiation occurs without local damping due to near-field energy exchange. By treating localization as an emergent property of stress-momentum geometry rather than a point constraint, the approach resolves classical self-force pathologies and makes testable predictions for high-frequency deviations from the Landau-Lifshitz equation.