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# Satellite Knot

Let be a knot inside a torus, and knot the torus in the shape of a second knot (called the companion knot) , with certain additional mild restrictions to avoid trivial cases. Then the new knot resulting from is called the satellite knot . All satellite knots are prime (Hoste et al. 1998). The illustration above illustrates a satellite knot of the trefoil knot, which is the form all satellite knots of 16 or fewer crossings take (Hoste et al. 1998). Satellites of the trefoil share the trefoil's chirality, and all have wrapping number 2.

Any satellite knot having wrapping number must have at least 27 crossings, and any satellite of the figure eight knot must have at least 17 crossings (Hoste et al. 1998). The numbers of satellite knots with crossings are 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 10, ... (OEIS A051765), so the satellite knot of minimal crossing number occurs for 13 crossings. A knot can be checked in the Wolfram Language to see if it is a satellite knot using KnotData[knot, "Satellite"] (although all knots currently implemented in the Wolfram Language are nonsatellite knots).

No satellite knot is an almost alternating knot. If a companion knot has crossing number and the satellite ravels times longitudinally around the solid torus, then it is conjectured that the satellite cannot be projected with fewer than crossings (Hoste et al. 1998).

Almost Alternating Knot, Cable Knot, Companion Knot, Composite Knot, Doubled Knot, Hyperbolic Knot, Torus Knot, Twist Knot

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## References

Adams, C. C. The Knot Book: An Elementary Introduction to the Mathematical Theory of Knots. New York: W. H. Freeman, pp. 115-118, 1994.Hoste, J.; Thistlethwaite, M.; and Weeks, J. "The First Knots." Math. Intell. 20, 33-48, Fall 1998.Sloane, N. J. A. Sequence A051765 in "The On-Line Encyclopedia of Integer Sequences."

Satellite Knot

## Cite this as:

Weisstein, Eric W. "Satellite Knot." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/SatelliteKnot.html