## LSU Doctoral Dissertations

#### Degree

Doctor of Philosophy (PhD)

#### Department

Department of Mathematics

Dissertation

#### Abstract

Suppose $(\M,\xi)$ be an overtwisted contact 3-manifold. We prove that any Legendrian and transverse link in $(\M,\xi)$ having overtwisted complement can be coarsely classified by their classical invariants. Next, we defined an invariant called the support genus for transverse links and extended the definition of support genus of Legendrian knots to Legendrian links and prove that any coarse equivalence class of Legendrian and transverse loose links has support genus zero. Further, we show that the converse is not true by explicitly constructing an example. We also find a relationship between the support genus of the transverse link and its Legendrian approximation. As a corollary to this, we show that loose, null-homologous, transverse knots have support genus zero and also give a condition when non-loose Legendrian knots have non-loose transverse push offs.

Vela-Vick, Shea