Abstract
Representations of solutions of boundary value problems for simple domains in the Monte Carlo algorithms are widely distributed [2]. In particular, widespread use is made of such a representation for the ball. It allows one to formally write an integral equation of the second kind for the required function in an arbitrary domain with regular boundary. Moreover, with the involvement of the joining conditions [1], one can picture a possible construction of a random process to “solve” the problem. However, the “walk in spheres” process, which solves the first boundary value problem for the Poisson equation, results in ɛ-biased estimators, and so the introduction of a regularization parameter is required.
The authors investigate in detail the “walk in hemispheres” method, which has been proposed earlier by A. S. Sipin [10] without full justification. The use of the Green’s function for the hemisphere makes it possible to obtain estimators for the first and the third boundary value problems, as well as for the problem with discontinuous derivative; for a broad class of domains, these estimators are shown to be unbiased. The algorithms proposed feature a high degree of parallelism. Results of solving model problems are presented.
Similar content being viewed by others
References
S. M. Ermakov, Monte Carlo Methods in Computational Mathematics: An Introductory Course (St. Petersburg, 2009).
S. M. Ermakov and G. A. Mikhailov, A Course in Statistical Modeling (Nauka, Moscow, 1976) [in Russian].
M. E. Muller, “Some Continuous Monte Carlo Methods for the Dirichlet Problem,” Ann. Math. Stat. 27(3), 569–589 (1956).
A. S. Sipin, “Solving First Boundary Value Problem for Elliptic Equation by Monte Carlo Method,” in Monte Carlo Methods in Comput. Math. and Math. Phys. (Novosibirsk, 1979), vol. 2, 113–119.
S. M. Ermakov, V. V. Nekrutkin, and A. S. Sipin, Random Processes for Classical Equations of Mathematical Physics (Nauka, Moscow, 1984; Kluwer, Dordrecht, 1989).
V. S. Vladimirov, Equations of Mathematical Physics (Nauka, Moscow, 1981; Marcel Dekker, New York, 1971).
G. A. Mikhailov, Weighted Algorithms for the Statistical Modeling (Institute of Computational Mathematics and Mathematical Geophysics SB RAS, Novosibirsk, 2003) [in Russian].
E. B. Dynkin and A. A. Yushkevich, Markov Processes—Theorems and Problems (Nauka, Moscow, 1967; Plenum, New York, 1969).
P. A. Meyer, Probability and Potentials (Blaisdell, New York, 1966; Mir, Moscow, 1973).
A. S. Sipin, “Walks inside Domains and Their Applications to Boundary Value Problems,” Proc. Conf. “Tikhonov and Contemporary Mathematics”, subsection “Computat. Math. and Informatics”. Moscow, 2006, 113–114.
N. A. Simonov, “Monte Carlo Methods for Solving Elliptic Equations with Boundary Conditions Containing the Normal Derivative,” Doklady Mathematics 74(2), 656–659 (2006).
N. A. Simonov, “Algorithms of Random Walks in Spheres for Solving Mixed Boundary Value Problem and the Neumann Problem,” Siberian J. Comput. Math 10(2), 209–220 (2007).
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © S.M. Ermakov, A.S. Sipin, 2009, published in Vestnik Sankt-Peterburgskogo Universiteta. Seriya 1. Matematika, Mekhanika, Astronomiya, 2009, No. 3, pp. 9–18.
About this article
Cite this article
Ermakov, S.M., Sipin, A.S. The “walk in hemispheres” process and its applications to solving boundary value problems. Vestnik St.Petersb. Univ.Math. 42, 155–163 (2009). https://doi.org/10.3103/S1063454109030029
Received:
Published:
Issue Date:
DOI: https://doi.org/10.3103/S1063454109030029