The least number of unknotted arcs lying above the plane in any projection. The knot 05-002 has bridge number 2. Such knots are called 2-bridge knots. There is a one-to-one correspondence between 2-bridge knots and rational knots. The knot 08-010 is a 3-bridge knot. A knot with bridge number is an -embeddable knot where .

# Bridge Number

## See also

Bridge Index## Explore with Wolfram|Alpha

## References

Adams, C. C.*The Knot Book: An Elementary Introduction to the Mathematical Theory of Knots.*New York: W. H. Freeman, pp. 64-67, 1994.Rolfsen, D.

*Knots and Links.*Wilmington, DE: Publish or Perish Press, p. 115, 1976.

## Referenced on Wolfram|Alpha

Bridge Number## Cite this as:

Weisstein, Eric W. "Bridge Number." From
*MathWorld*--A Wolfram Web Resource. https://mathworld.wolfram.com/BridgeNumber.html