Search for: All records

The proof of Witten's finiteness conjecture established that the Kauffman bracket skein modules of closed $$3$$-manifolds are finitely generated over $$\Q(A)$$. In this paper, we develop a novel method for computing these skein modules. We show that if the skein module $$S(M,\Q[A^\pmo])$$ of $$M$$ is tame (e.g. finitely generated over $$\Q[A^{\pm 1}]$$), and the $$SL(2, \C)$$-character scheme is reduced, then the dimension $$\dim_{\Q(A)}\, S(M, \Q(A))$$ is the number of closed points in this character scheme. This, in particular, verifies a conjecture in the literature relating $$\dim_{\Q(A)}\, S(M, \Q(A))$$ to the Abouzaid-Manolescu $$SL(2,\C)$$-Floer theoretic invariants, for infinite families of 3-manifolds. We prove a criterion for reducedness of character varieties of closed $$3$$-manifolds and use it to compute the skein modules of Dehn fillings of $(2,2n+1)$-torus knots and of the figure-eight knot. The later family gives the first instance of computations of skein modules for closed hyperbolic 3-manifolds. We also prove that the skein modules of rational homology spheres have dimension at least $$1$$ over $$\Q(A)$$. 

We use the degree of the colored Jones knot polynomials to show that the crossing number of a (p,q)‐cable of an adequate knot with crossing number c is larger than q^2 c. As an application, we determine the crossing number of 2‐cables of adequate knots. We also determine the crossing number of the connected sum of any adequate knot with a 2‐cable of an adequate knot. 

We point out that the strong slope conjecture implies that the degrees of the colored Jones knot polynomials detect the figure eight knot. Furthermore, we propose a characterization of alternating knots in terms of the Jones period and the degree span of the colored Jones polynomial. 

We consider hyperbolic links that admit alternating projections on surfaces in compact, irreducible 3-manifolds. We show that, under some mild hypotheses, the volume of the complement of such a link is bounded below in terms of a Kauffman bracket function defined on link diagrams on the surface. In the case that the 3-manifold is a thickened surface, this Kauffman bracket function leads to a Jones-type polynomial that is an isotopy invariant of links. We show that coefficients of this polynomial provide 2-sided linear bounds on the volume of hyperbolic alternating links in the thickened surface. As a corollary of the proof of this result, we deduce that the twist number of a reduced, twist reduced, checkerboard alternating link projection with disk regions, is an invariant of the link. 

We observe that the strong slope conjecture implies that the degree of the colored Jones polynomial detects all torus knots. As an application we obtain that an adequate knot that has the same colored Jones polynomial degrees as a torus knot must be a $(2,q)$-torus knot. 

We establish a relation between the "large r" asymptotics of the Turaev-Viro invariants $$TV_r $$and the Gromov norm of 3-manifolds. We show that for any orientable, compact 3-manifold $$M$$, with (possibly empty) toroidal boundary, $log|TVr(M)|$ is bounded above by a function linear in $$r$$ and whose slope is a positive universal constant times the Gromov norm of $$M$$. The proof combines TQFT techniques, geometric decomposition theory of 3-manifolds and analytical estimates of $6j$-symbols. We obtain topological criteria that can be used to check whether the growth is actually exponential; that is one has $$log|TVr(M)|\geq B r$$, for some $B>0$. We use these criteria to construct infinite families of hyperbolic 3-manifolds whose $SO(3)$- Turaev-Viro invariants grow exponentially. These constructions are essential for the results of article [3] where we make progress on a conjecture of Andersen, Masbaum and Ueno about the geometric properties of surface mapping class groups detected by the quantum representations. We also study the behavior of the Turaev-Viro invariants under cutting and gluing of 3-manifolds along tori. In particular, we show that, like the Gromov norm, the values of the invariants do not increase under Dehn filling and we give applications of this result on the question of the extent to which relations between the invariants TVr and hyperbolic volume are preserved under Dehn filling. Finally we give constructions of 3-manifolds, both with zero and non-zero Gromov norm, for which the Turaev-Viro invariants determine the Gromov norm.