To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.

Double torus knot

From Wikipedia, the free encyclopedia

 Double torus
Double torus
 4 1 knot
4 1 knot

In knot theory, a double torus knot is a closed curve drawn on the surface called a double torus (think of the surface of two doughnuts stuck together). More technically, a double torus knot is the homeomorphic image of a circle in which can be realized as a subset of a genus two handlebody in . If a link is a subset of a genus two handlebody, it is a double torus link.[1]

The simplest example of a double torus knot that is not a torus knot is the figure-eight knot.

While torus knots and links are well understood and completely classified, there are many open questions about double torus knots.

Two different notations exist for describing double torus knots. The T/I notation is given in F. Norwood, Curves on Surfaces[2] and a different notation is given in P. Hill, On double-torus knots (I).[3] The big problem, solved in the case of the torus, still open in the case of the double torus, is: when do two different notations describe the same knot?

YouTube Encyclopedic

  • 1/3
    1 483
    3 559
  • Torus knot animation
  • The Two Light Workers and the Double Torus
  • AlgTop21: The two-holed torus and 3-crosscaps surface



  1. ^ Dale Rolfsen, Knots and Links, Publish or Perish, Inc., 1976, ISBN 0-914098-16-0
  2. ^ Topology and its Applications 33 (1989) 241-246.
  3. ^ Journal of Knot Theory and its Ramifications, 1999.
This page was last edited on 7 June 2017, at 00:46.
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.