Monoids of O-type, subword reversing, and ordered groups

We describe a simple scheme for constructing finitely generated monoids in which left-divisibility is a linear ordering and for practically investigating these monoids. The approach is based on subword reversing, a general method of combinatorial group theory, and connected with Garside theory, here in a non-Noetherian context. As an application we describe several families of ordered groups whose space of left-invariant orderings has an isolated point, including torus knot groups and some of their amalgamated products.Comment: updated version with new result

Factorability, Discrete Morse Theory and a Reformulation of K(π, 1)-conjecture

The first aim of this thesis is to study factorable groups and monoids. We give a new family of examples for factorability structures, provided by Garside theory, in particular, we provide a factorability structure on braid groups. Furthermore, we investigate the connection between factorability structures and rewriting systems, and give conditions under which a factorability structure yields a complete rewriting system on a monoid. Moreover, we exhibit a factorability structure on the orthogonal group O(n) and the induced factorability structure on the reflection subgroup of type B(n). Another aim of this thesis is the study of Artin groups and monoids. We exhibit several chain complexes computing the homology of an Artin monoid. Moreover, we give a new proof for Dobrinskaya's Theorem which states a reformulation of the K(π,1)-conjecture for Artin groups