© | Dror Bar-Natan: The Knot Atlas: Torus Knots:
T(9,4)
T(9,4)
T(7,5)
T(7,5)
T(27,2)
TubePlot
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   The 27-Crossing Torus Knot T(27,2)

Visit T(27,2)'s page at Knotilus!

Acknowledgement

PD Presentation: X21,49,22,48 X49,23,50,22 X23,51,24,50 X51,25,52,24 X25,53,26,52 X53,27,54,26 X27,1,28,54 X1,29,2,28 X29,3,30,2 X3,31,4,30 X31,5,32,4 X5,33,6,32 X33,7,34,6 X7,35,8,34 X35,9,36,8 X9,37,10,36 X37,11,38,10 X11,39,12,38 X39,13,40,12 X13,41,14,40 X41,15,42,14 X15,43,16,42 X43,17,44,16 X17,45,18,44 X45,19,46,18 X19,47,20,46 X47,21,48,20

Gauss Code: {-8, 9, -10, 11, -12, 13, -14, 15, -16, 17, -18, 19, -20, 21, -22, 23, -24, 25, -26, 27, -1, 2, -3, 4, -5, 6, -7, 8, -9, 10, -11, 12, -13, 14, -15, 16, -17, 18, -19, 20, -21, 22, -23, 24, -25, 26, -27, 1, -2, 3, -4, 5, -6, 7}

Braid Representative:    

Alexander Polynomial: t-13 - t-12 + t-11 - t-10 + t-9 - t-8 + t-7 - t-6 + t-5 - t-4 + t-3 - t-2 + t-1 - 1 + t - t2 + t3 - t4 + t5 - t6 + t7 - t8 + t9 - t10 + t11 - t12 + t13

Conway Polynomial: 1 + 91z2 + 1365z4 + 8008z6 + 24310z8 + 43758z10 + 50388z12 + 38760z14 + 20349z16 + 7315z18 + 1771z20 + 276z22 + 25z24 + z26

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

Determinant and Signature: {27, 26}

Jones Polynomial: q13 + q15 - q16 + q17 - q18 + q19 - q20 + q21 - q22 + q23 - q24 + q25 - q26 + q27 - q28 + q29 - q30 + q31 - q32 + q33 - q34 + q35 - q36 + q37 - q38 + q39 - q40

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

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

Kauffman Polynomial: Not Available.

V2 and V3, the type 2 and 3 Vassiliev invariants: {91, 819}

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=26 is the signature of T(27,2). Nonzero entries off the critical diagonals (if any exist) are highlighted in red.

\ r
  \  
j \
0123456789101112131415161718192021222324252627χ
81                           1-1
79                            0
77                         11 0
75                            0
73                       11   0
71                            0
69                     11     0
67                            0
65                   11       0
63                            0
61                 11         0
59                            0
57               11           0
55                            0
53             11             0
51                            0
49           11               0
47                            0
45         11                 0
43                            0
41       11                   0
39                            0
37     11                     0
35                            0
33   11                       0
31                            0
29  1                         1
271                           1
251                           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[27, 2]]
Out[2]=   
 -Graphics- 
In[3]:=
Crossings[TorusKnot[27, 2]]
Out[3]=   
27
In[4]:=
PD[TorusKnot[27, 2]]
Out[4]=   
PD[X[21, 49, 22, 48], X[49, 23, 50, 22], X[23, 51, 24, 50], X[51, 25, 52, 24], 
 
>   X[25, 53, 26, 52], X[53, 27, 54, 26], X[27, 1, 28, 54], X[1, 29, 2, 28], 
 
>   X[29, 3, 30, 2], X[3, 31, 4, 30], X[31, 5, 32, 4], X[5, 33, 6, 32], 
 
>   X[33, 7, 34, 6], X[7, 35, 8, 34], X[35, 9, 36, 8], X[9, 37, 10, 36], 
 
>   X[37, 11, 38, 10], X[11, 39, 12, 38], X[39, 13, 40, 12], X[13, 41, 14, 40], 
 
>   X[41, 15, 42, 14], X[15, 43, 16, 42], X[43, 17, 44, 16], X[17, 45, 18, 44], 
 
>   X[45, 19, 46, 18], X[19, 47, 20, 46], X[47, 21, 48, 20]]
In[5]:=
GaussCode[TorusKnot[27, 2]]
Out[5]=   
GaussCode[-8, 9, -10, 11, -12, 13, -14, 15, -16, 17, -18, 19, -20, 21, -22, 23, 
 
>   -24, 25, -26, 27, -1, 2, -3, 4, -5, 6, -7, 8, -9, 10, -11, 12, -13, 14, 
 
>   -15, 16, -17, 18, -19, 20, -21, 22, -23, 24, -25, 26, -27, 1, -2, 3, -4, 5, 
 
>   -6, 7]
In[6]:=
BR[TorusKnot[27, 2]]
Out[6]=   
BR[2, {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
 
>    1, 1, 1}]
In[7]:=
alex = Alexander[TorusKnot[27, 2]][t]
Out[7]=   
      -13    -12    -11    -10    -9    -8    -7    -6    -5    -4    -3
-1 + t    - t    + t    - t    + t   - t   + t   - t   + t   - t   + t   - 
 
     -2   1        2    3    4    5    6    7    8    9    10    11    12    13
>   t   + - + t - t  + t  - t  + t  - t  + t  - t  + t  - t   + t   - t   + t
          t
In[8]:=
Conway[TorusKnot[27, 2]][z]
Out[8]=   
        2         4         6          8          10          12          14
1 + 91 z  + 1365 z  + 8008 z  + 24310 z  + 43758 z   + 50388 z   + 38760 z   + 
 
           16         18         20        22       24    26
>   20349 z   + 7315 z   + 1771 z   + 276 z   + 25 z   + z
In[9]:=
Select[AllKnots[], (alex === Alexander[#][t])&]
Out[9]=   
{}
In[10]:=
{KnotDet[TorusKnot[27, 2]], KnotSignature[TorusKnot[27, 2]]}
Out[10]=   
{27, 26}
In[11]:=
J=Jones[TorusKnot[27, 2]][q]
Out[11]=   
 13    15    16    17    18    19    20    21    22    23    24    25    26
q   + q   - q   + q   - q   + q   - q   + q   - q   + q   - q   + q   - q   + 
 
     27    28    29    30    31    32    33    34    35    36    37    38
>   q   - q   + q   - q   + q   - q   + q   - q   + q   - q   + q   - q   + 
 
     39    40
>   q   - q
In[12]:=
Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]
Out[12]=   
{}
In[13]:=
A2Invariant[TorusKnot[27, 2]][q]
Out[13]=   
NotAvailable
In[14]:=
Kauffman[TorusKnot[27, 2]][a, z]
Out[14]=   
NotAvailable
In[15]:=
{Vassiliev[2][TorusKnot[27, 2]], Vassiliev[3][TorusKnot[27, 2]]}
Out[15]=   
{91, 819}
In[16]:=
Kh[TorusKnot[27, 2]][q, t]
Out[16]=   
 25    27    29  2    33  3    33  4    37  5    37  6    41  7    41  8
q   + q   + q   t  + q   t  + q   t  + q   t  + q   t  + q   t  + q   t  + 
 
     45  9    45  10    49  11    49  12    53  13    53  14    57  15
>   q   t  + q   t   + q   t   + q   t   + q   t   + q   t   + q   t   + 
 
     57  16    61  17    61  18    65  19    65  20    69  21    69  22
>   q   t   + q   t   + q   t   + q   t   + q   t   + q   t   + q   t   + 
 
     73  23    73  24    77  25    77  26    81  27
>   q   t   + q   t   + q   t   + q   t   + q   t


Dror Bar-Natan: The Knot Atlas: Torus Knots: The Torus Knot T(27,2)
T(9,4)
T(9,4)
T(7,5)
T(7,5)