A hyperbolic 3-manifold is a 3-manifold equipped with a complete Riemannian metric of constant sectional curvature -1. In other words, it is the quotient of three-dimensional hyperbolic space by a subgroup of hyperbolic isometries acting freely and properly discontinuously. See also Kleinian model.
Its thick-thin decomposition has a thin part consisting of tubular neighborhoods of closed geodesics and/or ends which are the product of a Euclidean surface and the closed half-ray. The manifold is of finite volume if and only if its thick part is compact. In this case, the ends are of the form torus cross the closed half-ray and are called cusps.
The complements of knots and links in the 3-sphere are frequently cusped hyperbolic manifolds. Examples include the complements of the figure-eight knot and the Borromean rings and the Whitehead link. More generally, geometrization implies that a knot which is neither a satellite knot nor a torus knot is a hyperbolic knot.
The Weeks manifold has the smallest volume of any closed orientable hyperbolic 3-manifold.
Thurston gave a necessary and sufficient criterion for a surface bundle over the circle to be hyperbolic: the monodromy of the bundle should be pseudo-Anosov. This is part of his celebrated hyperbolization theorem for Haken manifolds.
According to Thurston's geometrization conjecture, proved by Perelman, any closed, irreducible, atoroidal 3-manifold with infinite fundamental group is hyperbolic. There is an analogous statement for 3-manifolds with boundary.
 See also
- Maclachlan, Colin; Reid, Alan W. (2003), The arithmetic of hyperbolic 3-manifolds, Graduate Texts in Mathematics 219, Berlin, New York: Springer-Verlag, ISBN 978-0-387-98386-8, MR 1937957
- Ratcliffe, John G. (2006) , Foundations of hyperbolic manifolds, Graduate Texts in Mathematics 149 (2nd ed.), Berlin, New York: Springer-Verlag, doi:10.1007/978-0-387-47322-2, ISBN 978-0-387-33197-3, MR 2249478
- W. Thurston, The geometry and topology of three-manifolds, Princeton lecture notes (1980). Available via MSRI: http://www.msri.org/publications/books/gt3m/
- W. Thurston, 3-dimensional geometry and topology, Princeton University Press. 1997.