AUTOMATIC STRUCTURES FOR TORUS LINK GROUPS

A general result of Epstein and Thurston implies that all link groups are automatic, but the proof provides no explicit automaton. Here we show that the groups of all torus links are groups of fractions of so-called Garside monoids, i.e., roughly speaking, monoids with a good theory of divisibility, which allows us to reprove that those groups are automatic, but, in addition, gives a completely explicit description of the involved automata, thus partially answering a question of D. F. Holt.

[1]  W. Magnus,et al.  Combinatorial Group Theory: COMBINATORIAL GROUP THEORY , 1967 .

[2]  Patrick Dehornoy Groupes de Garside , 2001 .

[3]  Gunter Malle,et al.  COMPLEX REFLECTION GROUPS, BRAID GROUPS, HECKE ALGEBRAS , 1998 .

[4]  R. Lyndon,et al.  Combinatorial Group Theory , 1977 .

[5]  Patrick Dehornoy Complete positive group presentations , 2001 .

[6]  Y. Lafont,et al.  Homology of gaussian groups , 2001, math/0111231.

[7]  Explicit Presentations for the Dual Braid Monoids , 2001, math/0111280.

[8]  R. Tennant Algebra , 1941, Nature.

[9]  Bestvina's Normal Form Complex and the Homology of Garside Groups , 2002, math/0202228.

[10]  D. Rolfsen Knots and Links , 2003 .

[11]  Matthieu Picantin,et al.  The Center of Thin Gaussian Groups , 2001 .

[12]  A. Clifford,et al.  The algebraic theory of semigroups , 1964 .

[13]  M. C. Hughes,et al.  Complex reflection groups , 1990 .

[14]  Jean Michel,et al.  Springer theory in braid groups and the Birman-Ko-Lee monoid , 2000 .

[15]  John H. Remmers ON THE GEOMETRY OF SEMIGROUP PRESENTATIONS , 1980 .

[16]  F. A. Garside,et al.  THE BRAID GROUP AND OTHER GROUPS , 1969 .

[17]  Egbert Brieskorn,et al.  Artin-Gruppen und Coxeter-Gruppen , 1972 .

[18]  Ki Hyoung Ko,et al.  Positive presentations of the braid groups and the embedding problem , 1999 .

[19]  Joan S. Birman,et al.  A new approach to the word and conjugacy problems in the braid groups , 1997 .

[20]  David Bessis The dual braid monoid , 2001 .

[21]  Matthieu Picantin Petits groupes gaussiens , 2000 .

[22]  J. Birman Braids, Links, and Mapping Class Groups. , 1975 .

[23]  Patrick Dehornoy,et al.  Braids and self-distributivity , 2000 .

[24]  Matthieu Picantin,et al.  THE CONJUGACY PROBLEM IN SMALL GAUSSIAN GROUPS , 2001 .

[25]  S. Adjan,et al.  Defining Relations and Algorithmic Problems for Groups and Semigroups , 1967 .

[26]  Peter M. Higgins,et al.  Techniques of semigroup theory , 1991 .

[27]  Emil Artin,et al.  Theorie der Zöpfe , 1925 .

[28]  Nicolas Bourbaki,et al.  Groupes et algèbres de Lie , 1971 .

[29]  Joan S. Birman,et al.  Braids, Links, and Mapping Class Groups. (AM-82) , 1975 .

[30]  Patrick Dehornoy,et al.  Groups with a complemented presentation , 1997 .

[31]  Patrick Dehornoy,et al.  Gaussian Groups and Garside Groups, Two Generalisations of Artin Groups , 1999 .

[32]  David B. A. Epstein,et al.  Word processing in groups , 1992 .