The study of orderable groups is a topic that is all too often overlooked as a topic in algebra. The subject of orderable groups is a field of study which is directly associated with algebraic group theory, algebraic topology, and set theory. This paper will act as a guide into the world of orderable groups. It begins by enlightening the reader to the fundamental axioms of orderable groups, as well as, noting various important groups on which orders are often considered. We will then consider more interesting groups, on which the placement of orders is considered less often. After considering the orderings placed on various groups, we wish to consider in further detail the topologies of the sets of these orders. In particular, it is important to consider whether the set of orders placed on a particular group is finite or uncountable. We prove the latter by creating a homeomorphism from the group to the Cantor set, a set which is known for its uncountability. / Master of Science

Suppose K is a fibered knot with bi-orderable knot group. We perform a topological winding operation to half-twist bands in a free incompressible Seifert surface Σ of K. This results in a Seifert surface Σ' with boundary that is a non-fibered knot K'. We call K a fibered base of K'. A fibered base exists for a large class of non-fibered knots. We prove K' has a bi-orderable knot group if Σ' is obtained from applying the winding operation to only one half-twist band of Σ. Utilizing a Seifert surface gluing technique, we obtain HNN extension group presentations for both knot groups that differ by only one relation. To show the knot group of K' is bi-orderable, we apply the following: Let G be a bi-ordered free group with order preserving automorphism ɑ. It is well known that the semidirect product ℤ ×ɑG is a bi-orderable group. If X is a basis of G, a presentation of ℤ ×ɑG is ⟨ t,X | R ⟩, where the relations are R = {txt-1}ɑ(x)-1 : x ∈ X}. If R' is any subset of R, we prove that the group H =⟨ t,X | R' ⟩ is bi-orderable. H is a special case of an HNN extension of G. Finally, we add new relations to the group presentation of H such that bi-orderability is preserved.

Let p and q be distinct primes, and G an elementary amenable group that is a residually finite p-group and a residually finite q-group. We conjecture that such groups G are left orderable. In this paper we show some results which came as attempts to prove this conjecture. In particular we give a condition under which split extensions of residually finite p-groups are again residually finite p-groups. We also give an example which shows that even for elementary amenable groups, it is not sufficient for biorderablity that the group be a residually finite p-group and a residually finite q-group. / Master of Science

In this paper, we present techniques for proving a group to be non-left-orderable or a unique product group. These methods involve the existence of a mapping from the group to R which obeys a left-multiplication criterion. By determining the existence or non-existence of such a mapping, the desired information about the group can be concluded. As examples, we apply this technique to groups of transformations in hyperbolic 2- and 3- space, and Fibonacci groups. / Master of Science

Nous pre´sentons une condition sur les groupes de Garside que nous appelons la structure de Dehornoy. Une ite´ration d’une telle structure conduit a` une ordre a` gauche sur le groupe. Nous montrons des conditions pour qu’un groupe de Garside admet une structure de Dehornoy, et nous appliquons ce crite`re pour prouver que les groupes d’Artin de type A et I2(m), m ≥ 4, ont des structures de Dehornoy. Nous montrons que les ordres a` gauche sur les groupes d’Artin de type A obtenus a` partir de leurs structures de Dehornoy sont les ordres de Dehornoy. Dans le cas des groupes d’Artin du type I2(m), m ≥ 4, nous montrons que les ordres a` gauche de´rive´es de leurs structures de Dehornoy co¨ıncident avec les ordres obtenus a` partir des plongements de ces groupes dans les groupes de tresses. / We introduce a condition on Garside groups that we call Dehornoy structure. An iteration of such a structure leads to a left order on the group. We show conditions for a Garside group to admit a Dehornoy structure, and we apply these criteria to prove that the Artin groups of type A and I2(m), m ≥ 4, have Dehornoy structures. We show that the left orders on the Artin groups of type A obtained from their Dehornoy structures are the Dehornoy orders. In the case of the Artin groups of type I2(m), m ≥ 4, we show that the left orders derived from their Dehornoy structures coincide with the orders obtained from embeddings of the groups into braid groups.