© | Dror Bar-Natan: The Knot Atlas: Torus Knots:
T(11,2)
T(11,2)
T(7,3)
T(7,3)
T(13,2)
TubePlot
This page is passe. Go here instead!

   The 13-Crossing Torus Knot T(13,2)

Visit T(13,2)'s page at Knotilus!

Acknowledgement

PD Presentation: X11,25,12,24 X25,13,26,12 X13,1,14,26 X1,15,2,14 X15,3,16,2 X3,17,4,16 X17,5,18,4 X5,19,6,18 X19,7,20,6 X7,21,8,20 X21,9,22,8 X9,23,10,22 X23,11,24,10

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

Braid Representative:    

Alexander Polynomial: t-6 - t-5 + t-4 - t-3 + t-2 - t-1 + 1 - t + t2 - t3 + t4 - t5 + t6

Conway Polynomial: 1 + 21z2 + 70z4 + 84z6 + 45z8 + 11z10 + z12

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

Determinant and Signature: {13, 12}

Jones Polynomial: q6 + q8 - q9 + q10 - q11 + q12 - q13 + q14 - q15 + q16 - q17 + q18 - q19

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

Coloured Jones Polynomial (in the 3-dimensional representation of sl(2); n=2): q12 + q15 - q17 + q18 - q20 + q21 - q23 + q24 - q26 + q27 - q29 + q30 - q32 + q33 - q35 + q36 - q38 - q41 + q42 - q44 + q45 - q47 + q48 - q50 + q51

A2 (sl(3)) Invariant: q22 + q24 + 2q26 + q28 + q30 - q50 - q52 - q54

Kauffman Polynomial: a-25z + a-24z2 - a-23z + a-23z3 - 2a-22z2 + a-22z4 + a-21z - 3a-21z3 + a-21z5 + 3a-20z2 - 4a-20z4 + a-20z6 - a-19z + 6a-19z3 - 5a-19z5 + a-19z7 - 4a-18z2 + 10a-18z4 - 6a-18z6 + a-18z8 + a-17z - 10a-17z3 + 15a-17z5 - 7a-17z7 + a-17z9 + 5a-16z2 - 20a-16z4 + 21a-16z6 - 8a-16z8 + a-16z10 - a-15z + 15a-15z3 - 35a-15z5 + 28a-15z7 - 9a-15z9 + a-15z11 + 6a-14 - 41a-14z2 + 91a-14z4 - 92a-14z6 + 46a-14z8 - 11a-14z10 + a-14z12 - 6a-13z + 35a-13z3 - 56a-13z5 + 36a-13z7 - 10a-13z9 + a-13z11 + 7a-12 - 56a-12z2 + 126a-12z4 - 120a-12z6 + 55a-12z8 - 12a-12z10 + a-12z12

V2 and V3, the type 2 and 3 Vassiliev invariants: {21, 91}

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=12 is the signature of T(13,2). Nonzero entries off the critical diagonals (if any exist) are highlighted in red.

\ r
  \  
j \
012345678910111213χ
39             1-1
37              0
35           11 0
33              0
31         11   0
29              0
27       11     0
25              0
23     11       0
21              0
19   11         0
17              0
15  1           1
131             1
111             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[13, 2]]
Out[2]=   
 -Graphics- 
In[3]:=
Crossings[TorusKnot[13, 2]]
Out[3]=   
13
In[4]:=
PD[TorusKnot[13, 2]]
Out[4]=   
PD[X[11, 25, 12, 24], X[25, 13, 26, 12], X[13, 1, 14, 26], X[1, 15, 2, 14], 
 
>   X[15, 3, 16, 2], X[3, 17, 4, 16], X[17, 5, 18, 4], X[5, 19, 6, 18], 
 
>   X[19, 7, 20, 6], X[7, 21, 8, 20], X[21, 9, 22, 8], X[9, 23, 10, 22], 
 
>   X[23, 11, 24, 10]]
In[5]:=
GaussCode[TorusKnot[13, 2]]
Out[5]=   
GaussCode[-4, 5, -6, 7, -8, 9, -10, 11, -12, 13, -1, 2, -3, 4, -5, 6, -7, 8, 
 
>   -9, 10, -11, 12, -13, 1, -2, 3]
In[6]:=
BR[TorusKnot[13, 2]]
Out[6]=   
BR[2, {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}]
In[7]:=
alex = Alexander[TorusKnot[13, 2]][t]
Out[7]=   
     -6    -5    -4    -3    -2   1        2    3    4    5    6
1 + t   - t   + t   - t   + t   - - - t + t  - t  + t  - t  + t
                                  t
In[8]:=
Conway[TorusKnot[13, 2]][z]
Out[8]=   
        2       4       6       8       10    12
1 + 21 z  + 70 z  + 84 z  + 45 z  + 11 z   + z
In[9]:=
Select[AllKnots[], (alex === Alexander[#][t])&]
Out[9]=   
{}
In[10]:=
{KnotDet[TorusKnot[13, 2]], KnotSignature[TorusKnot[13, 2]]}
Out[10]=   
{13, 12}
In[11]:=
J=Jones[TorusKnot[13, 2]][q]
Out[11]=   
 6    8    9    10    11    12    13    14    15    16    17    18    19
q  + q  - q  + q   - q   + q   - q   + q   - q   + q   - q   + q   - q
In[12]:=
Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]
Out[12]=   
{}
In[13]:=
ColouredJones[TorusKnot[13, 2], 2][q]
Out[13]=   
 12    15    17    18    20    21    23    24    26    27    29    30    32
q   + q   - q   + q   - q   + q   - q   + q   - q   + q   - q   + q   - q   + 
 
     33    35    36    38    41    42    44    45    47    48    50    51
>   q   - q   + q   - q   - q   + q   - q   + q   - q   + q   - q   + q
In[14]:=
A2Invariant[TorusKnot[13, 2]][q]
Out[14]=   
 22    24      26    28    30    50    52    54
q   + q   + 2 q   + q   + q   - q   - q   - q
In[15]:=
Kauffman[TorusKnot[13, 2]][a, z]
Out[15]=   
                                                       2       2      2
 6     7     z     z     z     z     z     z    6 z   z     2 z    3 z
--- + --- + --- - --- + --- - --- + --- - --- - --- + --- - ---- + ---- - 
 14    12    25    23    21    19    17    15    13    24    22     20
a     a     a     a     a     a     a     a     a     a     a      a
 
       2      2       2       2    3       3      3       3       3       3
    4 z    5 z    41 z    56 z    z     3 z    6 z    10 z    15 z    35 z
>   ---- + ---- - ----- - ----- + --- - ---- + ---- - ----- + ----- + ----- + 
     18     16      14      12     23    21     19      17      15      13
    a      a       a       a      a     a      a       a       a       a
 
     4       4       4       4       4        4    5       5       5       5
    z     4 z    10 z    20 z    91 z    126 z    z     5 z    15 z    35 z
>   --- - ---- + ----- - ----- + ----- + ------ + --- - ---- + ----- - ----- - 
     22    20      18      16      14      12      21    19      17      15
    a     a       a       a       a       a       a     a       a       a
 
        5    6       6       6       6        6    7       7       7       7
    56 z    z     6 z    21 z    92 z    120 z    z     7 z    28 z    36 z
>   ----- + --- - ---- + ----- - ----- - ------ + --- - ---- + ----- + ----- + 
      13     20    18      16      14      12      19    17      15      13
     a      a     a       a       a       a       a     a       a       a
 
     8       8       8       8    9       9       9    10       10       10
    z     8 z    46 z    55 z    z     9 z    10 z    z     11 z     12 z
>   --- - ---- + ----- + ----- + --- - ---- - ----- + --- - ------ - ------ + 
     18    16      14      12     17    15      13     16     14       12
    a     a       a       a      a     a       a      a      a        a
 
     11    11    12    12
    z     z     z     z
>   --- + --- + --- + ---
     15    13    14    12
    a     a     a     a
In[16]:=
{Vassiliev[2][TorusKnot[13, 2]], Vassiliev[3][TorusKnot[13, 2]]}
Out[16]=   
{21, 91}
In[17]:=
Kh[TorusKnot[13, 2]][q, t]
Out[17]=   
 11    13    15  2    19  3    19  4    23  5    23  6    27  7    27  8
q   + q   + q   t  + q   t  + q   t  + q   t  + q   t  + q   t  + q   t  + 
 
     31  9    31  10    35  11    35  12    39  13
>   q   t  + q   t   + q   t   + q   t   + q   t


Dror Bar-Natan: The Knot Atlas: Torus Knots: The Torus Knot T(13,2)
T(11,2)
T(11,2)
T(7,3)
T(7,3)