Bridge number

Bridge number

In a mathematical field of Knot theory, the Bridge number is an invariant of a knot. It is defined as the minimal number of bridges required in all the possible bridge representations of a knot. A bridge representation of a knot is a representation, such that the knot lies entirely in the plane apart for a couple of bridges whose projections onto the plane are straight lines.

It can be shown that every n-bridge knot can be decomposed into two trivial n-tangles and hence 2-bridge knots are rational knots.

ources

Peter Cromwell, "Knots and Links", Cambridge

Other invariants

* Linking coefficient
* Unknotting number
* Polygonal number

ee also

* 2-bridge knot


Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Omaha Road Bridge Number 15 — Omaha Road Bridge #15 The south end of the bridge, showing the concrete bobtail . Carries One track of the Union Pacific Railroad and Soo Line Railroad Crosses Missi …   Wikipedia

  • Northern Pacific Bridge Number 9 — Northern Pacific Bridge #9 Bridge #9 as seen from the 10th Avenue Bridge over the Mississippi River. Carries Bike and pedestrian lanes; formerly two railroad tracks Crosses …   Wikipedia

  • Number Ten Ox — is a fictional character from Barry Hughart s series Chronicles of Master Li and Number Ten Ox, set in a version of ancient China that never was. Lu Yu lives in the village of Ku fu with his aunt and uncle, his parents having died when he was ten …   Wikipedia

  • Bridge-class OBO carrier — Bridge classThe Bridge class OBO (Ore bulk oil carrier) was a series of six vessels, which were constructed for Bibby Line. Only one vessel of the class, the Furness Bridge , was built to the original design. It became a very controversial class… …   Wikipedia

  • Bridge of Orchy railway station — Bridge of Orchy Drochaid Urchaidh …   Wikipedia

  • Bridge Base Inc. — Bridge Base Incorporated is a business which established and maintains an online website. It was founded in 1990 by Fred Gitelman, President, and Dr. Sheri Winestock, Vice President. Their first two products, BASE II (1990) and BASE III (1991)… …   Wikipedia

  • Bridge financing — is a method of financing, used to maintain liquidity while waiting for an anticipated and reasonably expected inflow of cash. Bridge financing is commonly used when the cash flow from a sale of an asset is expected after the cash outlay for the… …   Wikipedia

  • Bridge 9 Records — Bridge Nine Records is a contemporary hardcore punk record label located in Boston, Massachusetts. Bridge Nine is owned by Chris Wrenn, who began the label in 1995 and produced its first release in 1996. The label gets is named as a metaphor for… …   Wikipedia

  • Bridge Cottage — is a 16th century thatched cottage in Flatford, East Bergholt, Suffolk, England. It has been a National Trust property since 1943. The National Trust market the property under the name Flatford: Bridge Cottage .The property is located in the… …   Wikipedia

  • Number Nine (album) — Number Nine Studio album by Chris Hülsbeck Released 2007 Genre Electronic Length 73:52 …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”