© | Dror Bar-Natan: The Knot Atlas: Torus Knots:
T(15,2)
T(15,2)
T(17,2)
T(17,2)
T(8,3)
TubePlot
This page is passe. Go here instead!

   The 16-Crossing Torus Knot T(8,3)

Visit T(8,3)'s page at Knotilus!

Acknowledgement

Further views:   Banif
Banco Internacional do Funchal

PD Presentation: X11,1,12,32 X22,2,23,1 X23,13,24,12 X2,14,3,13 X3,25,4,24 X14,26,15,25 X15,5,16,4 X26,6,27,5 X27,17,28,16 X6,18,7,17 X7,29,8,28 X18,30,19,29 X19,9,20,8 X30,10,31,9 X31,21,32,20 X10,22,11,21

Gauss Code: {2, -4, -5, 7, 8, -10, -11, 13, 14, -16, -1, 3, 4, -6, -7, 9, 10, -12, -13, 15, 16, -2, -3, 5, 6, -8, -9, 11, 12, -14, -15, 1}

Braid Representative:    

Alexander Polynomial: t-7 - t-6 + t-4 - t-3 + t-1 - 1 + t - t3 + t4 - t6 + t7

Conway Polynomial: 1 + 21z2 + 105z4 + 189z6 + 157z8 + 65z10 + 13z12 + z14

Other knots with the same Alexander/Conway Polynomial: {...}

Determinant and Signature: {3, 10}

Jones Polynomial: q7 + q9 - q16

Other knots (up to mirrors) with the same Jones Polynomial: {...}

Coloured Jones Polynomial (in the 3-dimensional representation of sl(2); n=2): q14 + q17 + q20 - q21 + q23 - q24 + q26 - q27 + q29 - q30 - q31 + q32 - q33 - q34 + q35 - q37 + q38 - q40 + q41 - q43 + q44 - q46 + q47

A2 (sl(3)) Invariant: Not Available.

Kauffman Polynomial: - 7a-18 + 21a-18z2 - 21a-18z4 + 8a-18z6 - a-18z8 + 21a-17z - 105a-17z3 + 189a-17z5 - 157a-17z7 + 65a-17z9 - 13a-17z11 + a-17z13 - 21a-16 + 126a-16z2 - 294a-16z4 + 346a-16z6 - 222a-16z8 + 78a-16z10 - 14a-16z12 + a-16z14 + 21a-15z - 105a-15z3 + 189a-15z5 - 157a-15z7 + 65a-15z9 - 13a-15z11 + a-15z13 - 15a-14 + 105a-14z2 - 273a-14z4 + 338a-14z6 - 221a-14z8 + 78a-14z10 - 14a-14z12 + a-14z14

V2 and V3, the type 2 and 3 Vassiliev invariants: {21, 84}

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=10 is the signature of T(8,3). Nonzero entries off the critical diagonals (if any exist) are highlighted in red.

\ r
  \  
j \
01234567891011χ
33           1-1
31         1  -1
29         11 0
27       11   0
25     1  1   0
23     11     0
21   11       0
19    1       1
17  1         1
151           1
131           1


Computer Talk. The data above can be recomputed by Mathematica using the package KnotTheory`. Following setup, the sample Mathematica session below reproduces most of the above data (Mathematica system prompts in blue, human input in red, Mathematica output in black):

In[1]:=    
<< KnotTheory`
Loading KnotTheory` (version of August 30, 2005, 10:15:35)...
In[2]:=
TubePlot[TorusKnot[8, 3]]
Out[2]=   
 -Graphics- 
In[3]:=
Crossings[TorusKnot[8, 3]]
Out[3]=   
16
In[4]:=
PD[TorusKnot[8, 3]]
Out[4]=   
PD[X[11, 1, 12, 32], X[22, 2, 23, 1], X[23, 13, 24, 12], X[2, 14, 3, 13], 
 
>   X[3, 25, 4, 24], X[14, 26, 15, 25], X[15, 5, 16, 4], X[26, 6, 27, 5], 
 
>   X[27, 17, 28, 16], X[6, 18, 7, 17], X[7, 29, 8, 28], X[18, 30, 19, 29], 
 
>   X[19, 9, 20, 8], X[30, 10, 31, 9], X[31, 21, 32, 20], X[10, 22, 11, 21]]
In[5]:=
GaussCode[TorusKnot[8, 3]]
Out[5]=   
GaussCode[2, -4, -5, 7, 8, -10, -11, 13, 14, -16, -1, 3, 4, -6, -7, 9, 10, -12, 
 
>   -13, 15, 16, -2, -3, 5, 6, -8, -9, 11, 12, -14, -15, 1]
In[6]:=
BR[TorusKnot[8, 3]]
Out[6]=   
BR[3, {1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2}]
In[7]:=
alex = Alexander[TorusKnot[8, 3]][t]
Out[7]=   
      -7    -6    -4    -3   1        3    4    6    7
-1 + t   - t   + t   - t   + - + t - t  + t  - t  + t
                             t
In[8]:=
Conway[TorusKnot[8, 3]][z]
Out[8]=   
        2        4        6        8       10       12    14
1 + 21 z  + 105 z  + 189 z  + 157 z  + 65 z   + 13 z   + z
In[9]:=
Select[AllKnots[], (alex === Alexander[#][t])&]
Out[9]=   
{}
In[10]:=
{KnotDet[TorusKnot[8, 3]], KnotSignature[TorusKnot[8, 3]]}
Out[10]=   
{3, 10}
In[11]:=
J=Jones[TorusKnot[8, 3]][q]
Out[11]=   
 7    9    16
q  + q  - q
In[12]:=
Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]
Out[12]=   
{}
In[13]:=
ColouredJones[TorusKnot[8, 3], 2][q]
Out[13]=   
 14    17    20    21    23    24    26    27    29    30    31    32    33
q   + q   + q   - q   + q   - q   + q   - q   + q   - q   - q   + q   - q   - 
 
     34    35    37    38    40    41    43    44    46    47
>   q   + q   - q   + q   - q   + q   - q   + q   - q   + q
In[14]:=
A2Invariant[TorusKnot[8, 3]][q]
Out[14]=   
NotAvailable
In[15]:=
Kauffman[TorusKnot[8, 3]][a, z]
Out[15]=   
                                    2        2        2        3        3
-7    21    15    21 z   21 z   21 z    126 z    105 z    105 z    105 z
--- - --- - --- + ---- + ---- + ----- + ------ + ------ - ------ - ------ - 
 18    16    14    17     15      18      16       14       17       15
a     a     a     a      a       a       a        a        a        a
 
        4        4        4        5        5      6        6        6
    21 z    294 z    273 z    189 z    189 z    8 z    346 z    338 z
>   ----- - ------ - ------ + ------ + ------ + ---- + ------ + ------ - 
      18      16       14       17       15      18      16       14
     a       a        a        a        a       a       a        a
 
         7        7    8         8        8       9       9       10       10
    157 z    157 z    z     222 z    221 z    65 z    65 z    78 z     78 z
>   ------ - ------ - --- - ------ - ------ + ----- + ----- + ------ + ------ - 
      17       15      18     16       14       17      15      16       14
     a        a       a      a        a        a       a       a        a
 
        11       11       12       12    13    13    14    14
    13 z     13 z     14 z     14 z     z     z     z     z
>   ------ - ------ - ------ - ------ + --- + --- + --- + ---
      17       15       16       14      17    15    16    14
     a        a        a        a       a     a     a     a
In[16]:=
{Vassiliev[2][TorusKnot[8, 3]], Vassiliev[3][TorusKnot[8, 3]]}
Out[16]=   
{21, 84}
In[17]:=
Kh[TorusKnot[8, 3]][q, t]
Out[17]=   
 13    15    17  2    21  3    19  4    21  4    23  5    25  5    23  6
q   + q   + q   t  + q   t  + q   t  + q   t  + q   t  + q   t  + q   t  + 
 
     27  7    25  8    27  8    29  9    31  9    29  10    33  11
>   q   t  + q   t  + q   t  + q   t  + q   t  + q   t   + q   t


Dror Bar-Natan: The Knot Atlas: Torus Knots: The Torus Knot T(8,3)
T(15,2)
T(15,2)
T(17,2)
T(17,2)