Article Contents
Article Contents

# Exponential growth rate for a singular linear stochastic delay differential equation

• We establish the existence of a deterministic exponential growth rate for the norm (on an appropriate function space) of the solution of the linear scalar stochastic delay equation $d X(t) = X(t-1) d W(t)$ which does not depend on the initial condition as long as it is not identically zero. Due to the singular nature of the equation this property does not follow from available results on stochastic delay differential equations. The key technique is to establish existence and uniqueness of an invariant measure of the projection of the solution onto the unit sphere in the chosen function space via asymptotic coupling and to prove a Furstenberg-Hasminskii-type formula (like in the finite dimensional case).
Mathematics Subject Classification: Primary: 34K50; Secondary: 60H10.

 Citation:

•  [1] L. Arnold, W. Kliemann and E. Oeljeklaus, Lyapunov exponents for linear stochastic systems, in "Lyapunov Exponents'' (eds. L. Arnold and V. Wihstutz) (Breman, 1984), Lecture Notes in Math., 1186, Springer, Berlin, (1986), 85-125.doi: 10.1007/BFb0076836. [2] G. Da Prato and J. Zabczyk, "Ergodicity for Infinite Dimensional Systems," London Mathematical Society Lecture Note Series, 229, Cambridge University Press, Cambridge, 1996.doi: 10.1017/CBO9780511662829. [3] H. Furstenberg, Noncommuting random products, Trans. Amer. Math. Soc., 108 (1963), 377-428. [4] M. Hairer, J. Mattingly and M. Scheutzow, Asymptotic coupling and a general form of Harris' theorem with applications to stochastic delay equations, Prob. Theory Rel. Fields, 149 (2011), 223-259.doi: 10.1007/s00440-009-0250-6. [5] P. Hall and C. Heyde, "Martingale Limit Theory and its Application," Probability and Mathematical Statistics, Academic Press, Inc. [Harcourt Brace Jovanovich, Publishers], New York-London, 1980. [6] R. Z. Has'minskiĭ, Necessary and sufficient conditions for asymptotic stability of linear stochastic systems, Theory Probability Appl., 12 (1967), 144-147. [7] R. S. Liptser and A. N. Shiryayev, "Statistics of Random Processes. I. General Theory," Translated by A. B. Aries, Applications of Mathematics, Vol. 5, Springer-Verlag, New York-Heidelberg, 1977. [8] S. Mohammed, Nonlinear flows of stochastic linear delay equations, Stochastics, 17 (1986), 207-213.doi: 10.1080/17442508608833390. [9] S. Mohammed and M. Scheutzow, Lyapunov exponents of linear stochastic functional differential equations driven by semimartingales. I. The multiplicative ergodic theory, Ann. Inst. H. Poincaré Probab. Statist., 32 (1996), 69-105. [10] S. Mohammed and M. Scheutzow, Lyapunov exponents of linear stochastic functional differential equations driven by semimartingales. II. Examples and case studies, Ann. Probab., 25 (1997), 1210-1240.doi: 10.1214/aop/1024404511. [11] M. Scheutzow, Exponential growth rates for stochastic delay differential equations, Stoch. Dyn., 5 (2005), 163-174.doi: 10.1142/S0219493705001468.