Phenomenology of Chan-Paton Defects on Open Strings
Ryan J. Buchanan, Parker Emmerson · 2025
This paper investigates the rôle of defects on extended quantum objects by generalizing the Chan-Paton factors of string theory as bimodules, wherein left-and right-actions encode brane dynamics. We introduce the concept of Chan-Paton defects on open strings, which partition the string worldsheet γ into stratified sectors γin and γout, separated by a defect modeled as a pseudoparticle. Both synthetic and analytic formulations are developed. Drawing on braidtheoretic considerations, we derive a generalized spin-statistics master equation that captures the behavior of fractional (anyonic) excitations. We demonstrate that Chan-Paton defects suppress entanglement between external degrees of freedom, attributing this to the dominance of internal interactions between non-defective string sectors. Building on prior investigations of the authors [7, 8], we show that such nonlocal or fractional statistics break epistemic harmony. In particular, we prove that inverse-limit (pyknotic) constructions for anyonic observables fail generically, precluding the existence of a fully nonperturbative anyonic regime. Two sources of this failure are identified: (a) measurement obstructions, and (b) breakdowns in domain-of-discourse-to-truth (DoD2T) mappings. These are addressed in the final section via categorical and modal completions. Taken together, these results suggest a unified framework for interpreting defects as both physical obstructions and semantic failures within extended quantum systems.