ArticleOriginal scientific text

Title

Destroying symmetry by orienting edges: complete graphs and complete bigraphs

Authors 1, 2

Affiliations

  1. Department of Computer Science, New Mexico State University, Las Cruces, NM 88003, USA
  2. Department of Mathematics, University of Louisville, Louisville, KY 40292, USA

Abstract

Our purpose is to introduce the concept of determining the smallest number of edges of a graph which can be oriented so that the resulting mixed graph has the trivial automorphism group. We find that this number for complete graphs is related to the number of identity oriented trees. For complete bipartite graphs Ks,t, s ≤ t, this number does not always exist. We determine for s ≤ 4 the values of t for which this number does exist.

Keywords

oriented graph, automorphism group

Bibliography

  1. G. Chartrand and L. Lesniak, Graphs & Digraphs, third edition (Chapman & Hall, New York, 1996).
  2. F. Harary, Graph Theory (Addison-Wesley, Reading MA 1969).
  3. F. Harary, R. Norman and D. Cartwright, Structural Models: An Introduction to the Theory of Directed Graphs (Wiley, New York, 1965).
  4. F. Harary and E.M. Palmer, Graphical Enumeration (Academic Press, New York, 1973).
  5. A. Blass and F. Harary, Properties of almost all graphs and complexes, J. Graph Theory 3 (1979) 225-240, doi: 10.1002/jgt.3190030305.
  6. E.M. Palmer, Graphical Evolution (Wiley, New York, 1983).
  7. F. Harary and G. Prins, The number of homeomorphically irreducible trees and other species, Acta Math. 101 (1959) 141-162, doi: 10.1007/BF02559543.
  8. F. Harary and R.W. Robinson, The number of identity oriented trees (to appear).
  9. D.J. McCarthy and L.V. Quintas, A stability theorem for minimum edge graphs with given abstract automorphism group, Trans. Amer. Math. Soc. 208 (1977) 27-39, doi: 10.1090/S0002-9947-1975-0369148-4.
  10. L.V. Quintas, Extrema concerning asymmetric graphs, J. Combin. Theory 5 (1968) 115-125.
Pages:
149-158
Main language of publication
English
Received
1999-12-21
Accepted
2001-07-02
Published
2001
Exact and natural sciences