7 1

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6_3

7_2

Contents

Image:7 1.gif
(KnotPlot image)

See the full Rolfsen Knot Table.

Visit 7 1's page at the Knot Server (KnotPlot driven, includes 3D interactive images!)

Visit 7_1's page at Knotilus!

Visit 7 1's page at the original Knot Atlas!

7_1 is also known as "The Septoil Knot", following the trefoil knot and the cinquefoil knot.


[edit] Knot presentations

Planar diagram presentation X1829 X3,10,4,11 X5,12,6,13 X7,14,8,1 X9,2,10,3 X11,4,12,5 X13,6,14,7
Gauss code -1, 5, -2, 6, -3, 7, -4, 1, -5, 2, -6, 3, -7, 4
Dowker-Thistlethwaite code 8 10 12 14 2 4 6
Conway Notation [7]


Minimum Braid Representative A Morse Link Presentation An Arc Presentation
Image:BraidPart3.gifImage:BraidPart3.gifImage:BraidPart3.gifImage:BraidPart3.gifImage:BraidPart3.gifImage:BraidPart3.gifImage:BraidPart3.gif
Image:BraidPart4.gifImage:BraidPart4.gifImage:BraidPart4.gifImage:BraidPart4.gifImage:BraidPart4.gifImage:BraidPart4.gifImage:BraidPart4.gif

Length is 7, width is 2,

Braid index is 2

Image:7 1_ML.gif Image:7 1_AP.gif
[{9, 2}, {1, 3}, {2, 4}, {3, 5}, {4, 6}, {5, 7}, {6, 8}, {7, 9}, {8, 1}]

[edit Notes on presentations of 7 1]

Knot 7_1.
Knot 7_1.
A graph, knot 7_1.
A graph, knot 7_1.

[edit] Three dimensional invariants

Symmetry type Reversible
Unknotting number 3
3-genus 3
Bridge index 2
Super bridge index 4
Nakanishi index 1
Maximal Thurston-Bennequin number [-14][5]
Hyperbolic Volume Not hyperbolic
A-Polynomial See Data:7 1/A-polynomial

[edit Notes for 7 1's three dimensional invariants]

[edit] Four dimensional invariants

Smooth 4 genus 3
Topological 4 genus 3
Concordance genus 3
Rasmussen s-Invariant -6

[edit Notes for 7 1's four dimensional invariants]

[edit] Polynomial invariants

Alexander polynomial t3t2 + t−1 + t−1t−2 + t−3
Conway polynomial z6 + 5z4 + 6z2 + 1
2nd Alexander ideal (db, data sources) {1}
Determinant and Signature { 7, -6 }
Jones polynomial q−3 + q−5q−6 + q−7q−8 + q−9q−10
HOMFLY-PT polynomial (db, data sources) z4a8−4z2a8−3a8 + z6a6 + 6z4a6 + 10z2a6 + 4a6
Kauffman polynomial (db, data sources) za13 + z2a12 + z3a11za11 + z4a10−2z2a10 + z5a9−3z3a9 + za9 + z6a8−5z4a8 + 7z2a8−3a8 + z5a7−4z3a7 + 3za7 + z6a6−6z4a6 + 10z2a6−4a6
The A2 invariant q30q28q26 + q18 + q16 + 2q14 + q12 + q10
The G2 invariant q168q136q134q128q126q124q118q116q102q96q94q92 + q88−2q84 + 2q80 + q78 + q72 + 3q70 + 2q68 + q64 + 2q62 + 2q60 + q58 + q54 + q52 + q50

[edit] "Similar" Knots (within the Atlas)

Same Alexander/Conway Polynomial: {}

Same Jones Polynomial (up to mirroring, q\leftrightarrow q^{-1}): {}

[edit] Vassiliev invariants

V2 and V3: (6, -14)

[edit] Khovanov Homology

The coefficients of the monomials trqj are shown, along with their alternating sums χ (fixed j, alternation over r). The squares with yellow highlighting are those on the "critical diagonals", where j−2r = s + 1 or j−2r = s−1, where s = -6 is the signature of 7 1. Nonzero entries off the critical diagonals (if any exist) are highlighted in red.   
\ r
  \  
j \
-7-6-5-4-3-2-10χ
-5       11
-7       11
-9     1  1
-11        0
-13   11   0
-15        0
-17 11     0
-19        0
-211       -1
Integral Khovanov Homology

(db, data source)

  
\dim{\mathcal G}_{2r+i}\operatorname{KH}^r_{\mathbb Z} i = −7 i = −5
r = −7 {\mathbb Z}
r = −6 {\mathbb Z}_2 {\mathbb Z}
r = −5 {\mathbb Z}
r = −4 {\mathbb Z}_2 {\mathbb Z}
r = −3 {\mathbb Z}
r = −2 {\mathbb Z}_2 {\mathbb Z}
r = −1
r = 0 {\mathbb Z} {\mathbb Z}

[edit] The Coloured Jones Polynomials

[edit] Computer Talk

Much of the above data can be recomputed by Mathematica using the package KnotTheory`. See A Sample KnotTheory` Session, or any of the Computer Talk sections above.

[edit] Modifying This Page

Read me first: Modifying Knot Pages

See/edit the Rolfsen Knot Page master template (intermediate).

See/edit the Rolfsen_Splice_Base (expert).

Back to the top.

6_3

7_2

Retrieved from "http://katlas.org/wiki/7_1"
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