$q$-Series Invariants of Three-Manifolds and Knots-Quivers Correspondence

Abstract

The Gukov-Pei-Putrov-Vafa (GPPV) conjecture is a relationship between two three-manifold invariants: the Witten-Reshetikhin-Turaev (WRT) invariant and the \(\widehat{Z}\) (``Z-hat'') invariant. In fact, WRT invariant is defined at roots of unity, $\mathbbm{q}\left(\exp\left(\frac{2πi}{k+2}\right),~k\in\mathbb{Z}_+,~\text{for}~SU(2)\right)$, and is generally a complex number, whereas $\hat{Z}$-invariant is a $q$-series with integer coefficients such that $|q|<1$. Therefore, $\hat{Z}$-invariant can be obtained from WRT-invariant by performing a particular analytic continuation, $\mathbbm{q}\rightarrow q$. In this thesis, we first examine this conjecture for $SO(3)$ and the ortho-symplectic supergroup $OSp(1|2)$. This is done by setting up the WRT invariant for the respective groups and then performing the particular analytic continuation to extract $\hat{Z}$. As a result of this exercise, we found that ${\hat{Z}}^{SU(2)}={\hat{Z}}^{SO(3)}$ and identified a relation between ${\hat{Z}}^{SU(2)}$ and ${\hat{Z}}^{OSp(1|2)}$. Motivated by the equality of $\hat{Z}$ for $SU(2)$ and $SO(3)$ groups, we study this conjecture for $SU(N)/{\mathbb{Z}}_m$ groups, where ${\mathbb{Z}}_m$ is a subgroup of ${\mathbb{Z}}_N$, in our second paper. We subsequently found that ${\hat{Z}}^{SU(N)/{\mathbb{Z}}_m}={\hat{Z}}^{SU(N)}$. Another theme of the thesis is to study a conjecture between knot theory and quiver representation theory. More precisely, this conjecture relates the generating function of the symmetric $r$-colored HOMFLY-PT polynomial with the motivic generating series associated with a symmetric quiver. In particular, we obtain a quiver representation for a family of knots called double twist knots $K(p,-m)$. Primarily, we exploit the reverse engineering of Melvin-Morton-Rozansky (MMR) formalism to deduce the pattern of the matrix for these quivers.

PhD Thesis, IIT Bombay, September 2024