In the branch of mathematics called knot theory, the volume conjecture is an open problem that relates quantum invariants of knots to the hyperbolic geometry of their complements.

Statement

Let O denote the unknot. For any knot K, let be the Kashaev invariant of K, which may be defined as where J_{K,N}(q) is the N-Colored Jones polynomial of K. The volume conjecture states that where is the simplicial volume of the complement of K in the 3-sphere, defined as follows. By the JSJ decomposition, the complement may be uniquely decomposed into a system of tori with H_i hyperbolic and E_j Seifert-fibered. The simplicial volume is then defined as the sum where is the hyperbolic volume of the hyperbolic manifold H_i. As a special case, if K is a hyperbolic knot, then the JSJ decomposition simply reads, and by definition the simplicial volume agrees with the hyperbolic volume.

History

The Kashaev invariant was first introduced by Rinat M. Kashaev in 1994 and 1995 for hyperbolic links as a state sum using the theory of quantum dilogarithms. Kashaev stated the formula of the volume conjecture in the case of hyperbolic knots in 1997. pointed out that the Kashaev invariant is related to the colored Jones polynomial by replacing the variable q with the root of unity e^{i\pi/N}. They used an R-matrix as the discrete Fourier transform for the equivalence of these two descriptions. This paper was the first to state the volume conjecture in its modern form using the simplicial volume. They also prove that the volume conjecture implies the following conjecture of Victor Vasiliev: The key observation in their proof is that if every Vassiliev invariant of a knot K is trivial, then for any N.

Status

The volume conjecture is open for general knots, and it is known to be false for arbitrary links. The volume conjecture has been verified in many special cases, including:

Relation to Chern-Simons theory

Using complexification, proved that for a hyperbolic knot K, where CS is the Chern–Simons invariant. They established a relationship between the complexified colored Jones polynomial and Chern–Simons theory.

Sources