author: | Philippe Andary |
title: | Finely homogeneous computations in free Lie algebras |
keywords: | Lie algebras, finely homogeneous computations
|
abstract: | We first give a fast algorithm to compute the maximal Lyndon word (with respect to lexicographic order) of Ly-alpha(A)
for every given multidegree alpha in Nk. We then give an algorithm to compute
all the words living in Ly-alpha(A) for any given alpha in Nk. The best known
method for generating Lyndon words is that of Duval [1], which gives a way
to go from every Lyndon word of length n to its successor (with respect to
lexicographic order by length), in space and worst case time complexity O(n).
Finally, we give a simple algorithm which uses Duvals method (the one
above) to compute the next standard bracketing of a Lyndon word for lexicographic
order by length. We can find an interesting application of this algorithm
in control theory, where one wants to compute within the command Lie algebra
of a dynamical system (letters are actually vector fields).
|
reference: |
Philippe Andary (1997),
Finely homogeneous computations in free Lie algebras,
Discrete Mathematics and Theoretical Computer Science 1, pp. 101-114 |
ps.gz-source: | dm010107.ps.gz |
ps-source: | dm010107.ps ( 139 K
) |
pdf-source: | dm010107.pdf ( 1742 K
) |