Abstract
Let L(Q t) denote the number of linear extensions of the t-dimensional Boolean lattice Q t. We use the entropy method of Kahn to show that
where the logarithms are base 2. We also find the exact maximum number of linear extensions of a d-regular bipartite order on n elements, in the case when n is a multiple of 2d.
Similar content being viewed by others
References
Bollobás, B.: Combinatorics, Cambridge University Press, 1986.
Bollobás, B. and Brightwell, G. R.: The number of k-SAT functions, Random Structures Algorithms 22 (2003), 227–247.
Brightwell, G. R.: The number of linear extensions of ranked posets, LSE-CDAM Research Report LSE-CDAM-2003-18, 2003.
Chung, F. R. K., Frankl, P., Graham R. and Shearer, J. B.: Some intersection theorems for ordered sets and graphs, J.Combin.Theory Ser.A. 48 (1986), 23–37.
Cover, T. and Thomas, J.: Elements of Information Theory, Wiley, New York, 1991.
Csiszár, I. and Körner, J.: Information Theory: Coding Theorems for Discrete Memoryless Systems, Academic Press, New York, 1981.
Fishburn, P. C. and Trotter, W. T.: Linear extensions of semiorders: A maximization problem, Discrete Math. 103 (1992), 25–40.
Galvin, D. and Tetali, P.: On weighted graph homomorphisms, Special DIMACS-AMS volume on Graph Homomorphisms and Statistical Physics Models, to appear.
Kahn, J.: An entropy approach to the hard-core model on bipartite graphs, Combin.Probab.Comp. 10 (2001), 219–237.
Kahn, J.: Entropy, independent sets and antichains: A new approach to Dedekind's problem, Proc.Amer.Math.Soc. 130 (2002), 371–378.
Kahn, J. and Kim, J. H.: Entropy and sorting, J.Comput.System Sci. 51 (1995), 390–399.
McEliece, R. J.: The Theory of Information and Coding, Addison-Wesley, London, 1977.
Radhakrishnan, J.: Entropy and counting, Preprint of a survey article (November 2001).
Sha, J. and Kleitman, D. J.: The number of linear extensions of subset ordering, Discrete Math. 63 (1987), 271–279.
A. Shastri, Number of linear extensions of symmetric KLYM posets, Utilitas Math. 53 (1998), 25–35.
Shepp, L. A.: The FKG inequality and some monotonicity properties of partial orders, SIAM J.Algebraic Discrete Methods 1 (1980), 295–299.
Shepp, L.: The XYZ conjecture and the FKG inequality, Ann.Probab. 10 (1982), 824–827.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Brightwell, G.R., Tetali, P. The Number of Linear Extensions of the Boolean Lattice. Order 20, 333–345 (2003). https://doi.org/10.1023/B:ORDE.0000034596.50352.f7
Issue Date:
DOI: https://doi.org/10.1023/B:ORDE.0000034596.50352.f7