Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-27T08:15:18.975Z Has data issue: false hasContentIssue false

On the N-tower problem and related problems

Published online by Cambridge University Press:  01 July 2016

F. Thomas Bruss*
Affiliation:
Université Libre de Bruxelles
Guy Louchard*
Affiliation:
Université Libre de Bruxelles
John W. Turner*
Affiliation:
Université Libre de Bruxelles
*
Postal address: Université Libre de Bruxelles, Département de Mathématique, CP 210 Boulevard du Triomphe, B-1050 Bruxelles, Belgium.
∗∗ Postal address: Université Libre de Bruxelles, Département d'Informatique, CP 212, Boulevard du Triomphe, B-1050 Bruxelles, Belgium. Email address: louchard@ulb.ac.be
∗∗∗ Postal address: Université Libre de Bruxelles, Département de Physique, CP 231, Boulevard du Triomphe, B-1050 Bruxelles, Belgium.

Abstract

Consider N towers each made up of a number of counters. At each step a tower is chosen at random, a counter removed which is then added to another tower also chosen at random. The probability distribution for the time needed to empty one of the towers is obtained in the case N = 3. Arguments are set forward as to why no simple formulae can be expected for N > 3. An asymptotic expression for the mean time before one of the towers becomes empty is derived in the case of four towers when they all initially contain a comparably large number of counters. We then study related problems, in particular the ruin problem for three players. Here we use simple martingale methodology as well as a solution proposed by T. S. Ferguson for a slightly modified problem. Throughout the paper it is our main objective to shed light on the reasons why the case N > 3 is so substantially different from the case N ≤ 3.

Type
General Applied Probability
Copyright
Copyright © Applied Probability Trust 2003 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Benedetti, R. and Petronio, C. (1992). Lectures on Hyperbolic Geometry. Springer, Berlin.CrossRefGoogle Scholar
Billingsley, P. (1995). Probability and Measure, 3rd edn. John Wiley, New York.Google Scholar
Bruss, F. T. (1996). A note on Ferguson's ruin problem. Tech. Rep., ISRO, Université Libre de Bruxelles.Google Scholar
Engel, A. (1993). The computer solves the three tower problem. Amer. Math. Monthly 100, 6264.Google Scholar
Feller, W. (1968). Introduction to Probability Theory and Its Applications, Vol. I, 3rd edn. John Wiley, New York.Google Scholar
Ferguson, T. S. (1995). Gambler's ruin in three dimensions. Unpublished manuscript. Available at http://www.math.ucla.edu/simtom/.Google Scholar
Itô, K. and McKean, H. P. Jr. (1974). Diffusion Processes and their Sample Paths, 2nd printing. Springer, Berlin.Google Scholar
Lavrentiev, M. A. and Chabat, B. V. (1972). Méthodes de la théorie des fonctions d'une variable complexe. Éditions Mir, Moscow.Google Scholar
Lévy, P., (1948). Processus Stochastiques et Mouvement Brownien. Gauthier-Villars, Paris.Google Scholar
Li, S. Y. R. (1980). A martingale approach to the study of the occurrence of patterns in repeated experiments. Ann. Prob. 8, 11711175.Google Scholar
Sansone, G. and Gerretsen, J. (1969). Lectures on the Theory of Functions of a Complex Variable. II: Geometric Theory. Wolters-Noordhoff, Groningen.Google Scholar
Spitzer, F. (1964). Principles of Random Walk. Van Nostrand, D., Princeton, NJ.Google Scholar
Stirzaker, D. (1994). Tower problems and martingales. Math. Scientist 19, 5259.Google Scholar
Turner, J. W. (1984). On the quantum particle in a polyhedral box. J. Phys. A 17, 27912797.Google Scholar