7 7

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7 6.gif

7_6

8 1.gif

8_1

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7 7 Quick Notes




Ornamental knot
Mongolian ornament ; sum of two 7.7
Depiction with three loops
Sum of 4.1 and 7.7

Knot presentations

Planar diagram presentation X1425 X5,10,6,11 X3948 X9,3,10,2 X11,14,12,1 X7,13,8,12 X13,7,14,6
Gauss code -1, 4, -3, 1, -2, 7, -6, 3, -4, 2, -5, 6, -7, 5
Dowker-Thistlethwaite code 4 8 10 12 2 14 6
Conway Notation [21112]

Three dimensional invariants

Symmetry type Reversible
Unknotting number 1
3-genus 2
Bridge index 2
Super bridge index 4
Nakanishi index 1
Maximal Thurston-Bennequin number Failed to parse (syntax error): {\displaystyle \text{$\$$Failed}}
Hyperbolic Volume 7.64338
A-Polynomial See Data:7 7/A-polynomial

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

Four dimensional invariants

Smooth 4 genus
Topological 4 genus
Concordance genus
Rasmussen s-Invariant 0

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

Polynomial invariants

Alexander polynomial
Conway polynomial
2nd Alexander ideal (db, data sources)
Determinant and Signature { 21, 0 }
Jones polynomial
HOMFLY-PT polynomial (db, data sources)
Kauffman polynomial (db, data sources)
The A2 invariant
The G2 invariant

Vassiliev invariants

V2 and V3: (-1, -1)
V2,1 through V6,9:
V2,1 V3,1 V4,1 V4,2 V4,3 V5,1 V5,2 V5,3 V5,4 V6,1 V6,2 V6,3 V6,4 V6,5 V6,6 V6,7 V6,8 V6,9

V2,1 through V6,9 were provided by Petr Dunin-Barkowski <barkovs@itep.ru>, Andrey Smirnov <asmirnov@itep.ru>, and Alexei Sleptsov <sleptsov@itep.ru> and uploaded on October 2010 by User:Drorbn. Note that they are normalized differently than V2 and V3.

Khovanov Homology

The coefficients of the monomials are shown, along with their alternating sums (fixed , alternation over ). The squares with yellow highlighting are those on the "critical diagonals", where or , where 0 is the signature of 7 7. Nonzero entries off the critical diagonals (if any exist) are highlighted in red.

\ r
  \  
j \
-3-2-101234χ
9       11
7      1 -1
5     21 1
3    21  -1
1   22   0
-1  23    1
-3 11     0
-5 2      2
-71       -1

Computer Talk

Much of the above data can be recomputed by Mathematica using the package KnotTheory`. See A Sample KnotTheory` Session.

In[1]:=    
<< KnotTheory`
Loading KnotTheory` (version of August 17, 2005, 14:44:34)...
In[2]:=
Crossings[Knot[7, 7]]
Out[2]=  
7
In[3]:=
PD[Knot[7, 7]]
Out[3]=  
PD[X[1, 4, 2, 5], X[5, 10, 6, 11], X[3, 9, 4, 8], X[9, 3, 10, 2], 
  X[11, 14, 12, 1], X[7, 13, 8, 12], X[13, 7, 14, 6]]
In[4]:=
GaussCode[Knot[7, 7]]
Out[4]=  
GaussCode[-1, 4, -3, 1, -2, 7, -6, 3, -4, 2, -5, 6, -7, 5]
In[5]:=
BR[Knot[7, 7]]
Out[5]=  
BR[4, {1, -2, 1, -2, 3, -2, 3}]
In[6]:=
alex = Alexander[Knot[7, 7]][t]
Out[6]=  
     -2   5          2

9 + t - - - 5 t + t

t
In[7]:=
Conway[Knot[7, 7]][z]
Out[7]=  
     2    4
1 - z  + z
In[8]:=
Select[AllKnots[], (alex === Alexander[#][t])&]
Out[8]=  
{Knot[7, 7], Knot[11, NonAlternating, 28]}
In[9]:=
{KnotDet[Knot[7, 7]], KnotSignature[Knot[7, 7]]}
Out[9]=  
{21, 0}
In[10]:=
J=Jones[Knot[7, 7]][q]
Out[10]=  
     -3   3    3            2      3    4

4 - q + -- - - - 4 q + 3 q - 2 q + q

          2   q
q
In[11]:=
Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]
Out[11]=  
{Knot[7, 7]}
In[12]:=
A2Invariant[Knot[7, 7]][q]
Out[12]=  
  -10    -8    -6   2     2    4    6    10    12    14

-q + q + q + -- + q - q - q - q + q + q

                    2
q
In[13]:=
Kauffman[Knot[7, 7]][a, z]
Out[13]=  
                                           2      2                3
    -4   2    2 z   3 z            2   2 z    6 z       2  2   4 z

2 + a + -- + --- + --- + a z - 7 z - ---- - ---- - 3 a z - ---- -

          2    3     a                   4      2                3
         a    a                         a      a                a

    3                            4      4                5      5
 8 z         3    3  3      4   z    2 z       2  4   2 z    5 z
 ---- - 3 a z  + a  z  + 4 z  + -- + ---- + 3 a  z  + ---- + ---- + 
  a                              4     2                3     a
                                a     a                a

                6
      5    6   z
 3 a z  + z  + --
                2
a
In[14]:=
{Vassiliev[2][Knot[7, 7]], Vassiliev[3][Knot[7, 7]]}
Out[14]=  
{0, -1}
In[15]:=
Kh[Knot[7, 7]][q, t]
Out[15]=  
3           1       2       1      1      2               3      3  2

- + 2 q + ----- + ----- + ----- + ---- + --- + 2 q t + 2 q t + q t + q 7 3 5 2 3 2 3 q t

         q  t    q  t    q  t    q  t

    5  2    5  3    7  3    9  4
2 q t + q t + q t + q t