# (−2,3,7) pretzel knot

(−2,3,7) pretzel knot
Arf invariant0
Crosscap no.2
Crossing no.12
Hyperbolic volume3.66386[1]
Unknotting no.5
Conway notation[−2,3,7]
Dowker notation4, 8, -16, 2, -18, -20, -22, -24, -6, -10, -12, -14
D-T name12n242
Last /Next12n241 12n243
Other
hyperbolic, fibered, pretzel, reversible

In geometric topology, a branch of mathematics, the (−2, 3, 7) pretzel knot, sometimes called the Fintushel–Stern knot (after Ron Fintushel and Ronald J. Stern), is an important example of a pretzel knot which exhibits various interesting phenomena under three-dimensional and four-dimensional surgery constructions.

## Mathematical properties

The (−2, 3, 7) pretzel knot has 7 exceptional slopes, Dehn surgery slopes which give non-hyperbolic 3-manifolds. Among the enumerated knots, the only other hyperbolic knot with 7 or more is the figure-eight knot, which has 10. All other hyperbolic knots are conjectured to have at most 6 exceptional slopes.

A pretzel (−2,3,7) pretzel knot.

## References

1. ^ Agol, Ian (2010), "The minimal volume orientable hyperbolic 2-cusped 3-manifolds", Proceedings of the American Mathematical Society, 138 (10): 3723–3732, arXiv:0804.0043, doi:10.1090/S0002-9939-10-10364-5, MR 2661571.