TY - GEN

T1 - A hopf-algebraic formula for compositions of noncommuting flows

AU - Gehrig, Eric

AU - Kawski, Matthias

PY - 2008/12/1

Y1 - 2008/12/1

N2 - The Chen-Fliess series is known to be an exponential Lie series. Previously explicit formulas for the iterated integral coefficients were known only for its factorization into a directed infinite product of exponentials. This factorization uses Hall sets and the Zinbiel product. We use the underlying Hopf algebra structure to derive explicit formulas for the corresponding coefficients in the logarithm of the series. This allows one to express the series as a single exponential. This work is closely related to Fer and Magnus expansions, and has interpretations in terms of a continuous Campbell-Baker-Hausdorff formula. The result facilitates work in nonlinear control, numerical integration and various applications that involve compositions of noncommuting flows.

AB - The Chen-Fliess series is known to be an exponential Lie series. Previously explicit formulas for the iterated integral coefficients were known only for its factorization into a directed infinite product of exponentials. This factorization uses Hall sets and the Zinbiel product. We use the underlying Hopf algebra structure to derive explicit formulas for the corresponding coefficients in the logarithm of the series. This allows one to express the series as a single exponential. This work is closely related to Fer and Magnus expansions, and has interpretations in terms of a continuous Campbell-Baker-Hausdorff formula. The result facilitates work in nonlinear control, numerical integration and various applications that involve compositions of noncommuting flows.

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U2 - 10.1109/CDC.2008.4738914

DO - 10.1109/CDC.2008.4738914

M3 - Conference contribution

AN - SCOPUS:62949191326

SN - 9781424431243

T3 - Proceedings of the IEEE Conference on Decision and Control

SP - 1569

EP - 1574

BT - Proceedings of the 47th IEEE Conference on Decision and Control, CDC 2008

T2 - 47th IEEE Conference on Decision and Control, CDC 2008

Y2 - 9 December 2008 through 11 December 2008

ER -