Cinquefoil | |
---|---|
![]() | |
Common name | Double overhand knot |
Arf invariant | 1 |
Braid length | 5 |
Braid no. | 2 |
Bridge no. | 2 |
Crosscap no. | 1 |
Crossing no. | 5 |
Genus | 2 |
Hyperbolic volume | 0 |
Stick no. | 8 |
Unknotting no. | 2 |
Conway notation | [5] |
A–B notation | 51 |
Dowker notation | 6, 8, 10, 2, 4 |
Last / Next | 41 / 52 |
Other | |
alternating, torus, fibered, prime, reversible |
In knot theory, the cinquefoil knot, also known as Solomon's seal knot or the pentafoil knot, is one of two knots with crossing number five, the other being the three-twist knot. It is listed as the 51 knot in the Alexander-Briggs notation, and can also be described as the (5,2)-torus knot. The cinquefoil is the closed version of the double overhand knot.
Properties[edit]
The cinquefoil is a prime knot. Its writhe is 5, and it is invertible but not amphichiral.[1] Its Alexander polynomial is
- ,
its Conway polynomial is
- ,
and its Jones polynomial is
These are the same as the Alexander, Conway, and Jones polynomials of the knot 10132. However, the Kauffman polynomial can be used to distinguish between these two knots.
History[edit]
The name "cinquefoil" comes from the five-petaled flowers of plants in the genus Potentilla.
![](https://upload.wikimedia.org/wikipedia/commons/thumb/b/ba/Cinquefoil_Knot.jpg/220px-Cinquefoil_Knot.jpg)
See also[edit]
References[edit]
Further reading[edit]
- A Pentafoil Knot at the Wayback Machine (archived June 4, 2004)
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction