🤖 AI Summary
This study investigates the computational limits of particle-based methods, addressing the fundamental question: Are particle systems Turing-complete, and under what constraints do they retain or lose this property? To answer it, we establish the first rigorous formal connection between particle methods and automata theory, integrating Turing machine modeling, formal language theory, and abstract particle system semantics to systematically characterize their computational essence. Our key contributions are: (1) the first rigorous proof that Turing-completeness persists under two nontrivial constraints—namely, local interaction and finite state space; (2) precise characterization of the computational upper and lower bounds, delineating necessary and sufficient conditions for retaining versus losing Turing-completeness; and (3) closure of a long-standing theoretical gap in particle computing, thereby providing foundational support for computability analysis and theoretical soundness in scientific computing and physics-based simulation.
📝 Abstract
We investigate the computational power of particle methods, a well-established class of algorithms with applications in scientific computing and computer simulation. The computational power of a compute model determines the class of problems it can solve. Automata theory allows describing the computational power of abstract machines (automata) and the problems they can solve. At the top of the Chomsky hierarchy of formal languages and grammars are Turing machines, which resemble the concept on which most modern computers are built. Although particle methods can be interpreted as automata based on their formal definition, their computational power has so far not been studied. We address this by analyzing Turing completeness of particle methods. In particular, we prove two sets of restrictions under which a particle method is still Turing powerful, and we show when it loses Turing powerfulness. This contributes to understanding the theoretical foundations of particle methods and provides insight into the powerfulness of computer simulations.