Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T04:37:13.501Z Has data issue: false hasContentIssue false

The probability that a point of a tree is fixed

Published online by Cambridge University Press:  24 October 2008

Frank Harary
Affiliation:
University of Michigan, Ann Arbor, U.S.A.
Edgar M. Palmer
Affiliation:
Michigan State University, East Lansing, U.S.A.

Abstract

Using arguments involving combinatorial enumeration and asymptotics we compute the probability that a point of a random tree is fixed. The method is also applied to homeomorphically irreducible trees to illustrate how it works for other species of trees. To the nearest per cent, the limiting probability of a fixed point in a randomtree is 70%, and for homeomorphically irreducible trees it is 20%.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1979

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

REFERENCES

(1)Harary, F. and Palmer, E. M.Graphical Enumeration (New York, Academic Press, 1973).Google Scholar
(2)Harary, F. and Palmer, E. M.Orbits in random trees. Annals New York Acad. Sci. (To appear.)Google Scholar
(3)Harary, F. and Prins, G.The number of homeomorphically irreducible trees, and other species. Acta Math. 101, (1959), 141162.CrossRefGoogle Scholar
(4)Harary, F. and Read, R. C. Is the null graph a pointless concept? Graphs and combinatorics, p. 38, ed. Bari, R. A. and Harary, F.. (New York, Springer, 1974).Google Scholar
(5)Harary, F., Robinson, R. W. and Schwenk, A. J.Twenty-step algorithm for determining the asymptotic number of trees of various species. J. Austral. Math. Soc. 20 (Series A) (1975), 483503.Google Scholar
(6)Otter, R.The number of trees. Ann. of Math. 49, (1948), 583599.CrossRefGoogle Scholar
(7)Palmer, E. M. and Schwenk, A. J.The number of trees in a random forest, J. Combinatorial Theory (To appear.)Google Scholar
(8)Pólya, G.Kombinatorische Anzahlbestimmungen für Gruppen, Graphen und chemische Verbindungen. Acta Math. 68, (1937), 145254.Google Scholar
(9)Robinson, R. W. and Schwenk, A. J.The distribution of degrees in a large random tree. Discrete Math. 12 (1975), 359372.Google Scholar