Improved bounds for the number of forests and acyclic orientations in the square lattice
The electronic journal of combinatorics, Tome 10 (2003)
Voir la notice de l'article provenant de la source The Electronic Journal of Combinatorics website
Zbl EuDML
In a recent paper Merino and Welsh (1999) studied several counting problems on the square lattice $L_n$. There the authors gave the following bounds for the asymptotics of $f(n)$, the number of forests of $L_n$, and $\alpha(n)$, the number of acyclic orientations of $L_n$: $$3.209912 \le \lim_{n\to\infty} f(n)^{1/n^2} \le 3.84161$$ and $$22/7 \le \lim_{n\to\infty} \alpha(n)^{1/n^2} \le 3.70925.$$ In this paper we improve these bounds as follows: $$3.64497 \le \lim_{n\to\infty} f(n)^{1/n^2} \le 3.74101$$ and $$3.41358 \le \lim_{n\to\infty} \alpha(n)^{1/n^2} \le 3.55449.$$ We obtain this by developing a method for computing the Tutte polynomial of the square lattice and other related graphs based on transfer matrices.
DOI :
10.37236/1697
Classification :
05C50, 05C35, 05A16
Mots-clés : asymptotics, forests, Tutte polynomial
Mots-clés : asymptotics, forests, Tutte polynomial
N. Calkin; C. Merino; S. Noble; M. Noy. Improved bounds for the number of forests and acyclic orientations in the square lattice. The electronic journal of combinatorics, Tome 10 (2003). doi: 10.37236/1697
@article{10_37236_1697,
author = {N. Calkin and C. Merino and S. Noble and M. Noy},
title = {Improved bounds for the number of forests and acyclic orientations in the square lattice},
journal = {The electronic journal of combinatorics},
year = {2003},
volume = {10},
doi = {10.37236/1697},
zbl = {1020.05041},
url = {http://geodesic.mathdoc.fr/articles/10.37236/1697/}
}
TY - JOUR AU - N. Calkin AU - C. Merino AU - S. Noble AU - M. Noy TI - Improved bounds for the number of forests and acyclic orientations in the square lattice JO - The electronic journal of combinatorics PY - 2003 VL - 10 UR - http://geodesic.mathdoc.fr/articles/10.37236/1697/ DO - 10.37236/1697 ID - 10_37236_1697 ER -
%0 Journal Article %A N. Calkin %A C. Merino %A S. Noble %A M. Noy %T Improved bounds for the number of forests and acyclic orientations in the square lattice %J The electronic journal of combinatorics %D 2003 %V 10 %U http://geodesic.mathdoc.fr/articles/10.37236/1697/ %R 10.37236/1697 %F 10_37236_1697
Cité par Sources :