© | Dror Bar-Natan: The Knot Atlas: Torus Knots:
T(17,2)
T(17,2)
T(10,3)
T(10,3)
T(19,2)
TubePlot
This page is passe. Go here instead!

   The 19-Crossing Torus Knot T(19,2)

Visit T(19,2)'s page at Knotilus!

Acknowledgement

PD Presentation: X13,33,14,32 X33,15,34,14 X15,35,16,34 X35,17,36,16 X17,37,18,36 X37,19,38,18 X19,1,20,38 X1,21,2,20 X21,3,22,2 X3,23,4,22 X23,5,24,4 X5,25,6,24 X25,7,26,6 X7,27,8,26 X27,9,28,8 X9,29,10,28 X29,11,30,10 X11,31,12,30 X31,13,32,12

Gauss Code: {-8, 9, -10, 11, -12, 13, -14, 15, -16, 17, -18, 19, -1, 2, -3, 4, -5, 6, -7, 8, -9, 10, -11, 12, -13, 14, -15, 16, -17, 18, -19, 1, -2, 3, -4, 5, -6, 7}

Braid Representative:    

Alexander Polynomial: 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

Conway Polynomial: 1 + 45z2 + 330z4 + 924z6 + 1287z8 + 1001z10 + 455z12 + 120z14 + 17z16 + z18

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

Determinant and Signature: {19, 18}

Jones Polynomial: q9 + q11 - q12 + q13 - q14 + q15 - q16 + q17 - q18 + q19 - q20 + q21 - q22 + q23 - q24 + q25 - q26 + q27 - q28

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: {45, 285}

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=18 is the signature of T(19,2). Nonzero entries off the critical diagonals (if any exist) are highlighted in red.

\ r
  \  
j \
012345678910111213141516171819χ
57                   1-1
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     11             0
27                    0
25   11               0
23                    0
21  1                 1
191                   1
171                   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[19, 2]]
Out[2]=   
 -Graphics- 
In[3]:=
Crossings[TorusKnot[19, 2]]
Out[3]=   
19
In[4]:=
PD[TorusKnot[19, 2]]
Out[4]=   
PD[X[13, 33, 14, 32], X[33, 15, 34, 14], X[15, 35, 16, 34], X[35, 17, 36, 16], 
 
>   X[17, 37, 18, 36], X[37, 19, 38, 18], X[19, 1, 20, 38], X[1, 21, 2, 20], 
 
>   X[21, 3, 22, 2], X[3, 23, 4, 22], X[23, 5, 24, 4], X[5, 25, 6, 24], 
 
>   X[25, 7, 26, 6], X[7, 27, 8, 26], X[27, 9, 28, 8], X[9, 29, 10, 28], 
 
>   X[29, 11, 30, 10], X[11, 31, 12, 30], X[31, 13, 32, 12]]
In[5]:=
GaussCode[TorusKnot[19, 2]]
Out[5]=   
GaussCode[-8, 9, -10, 11, -12, 13, -14, 15, -16, 17, -18, 19, -1, 2, -3, 4, -5, 
 
>   6, -7, 8, -9, 10, -11, 12, -13, 14, -15, 16, -17, 18, -19, 1, -2, 3, -4, 5, 
 
>   -6, 7]
In[6]:=
BR[TorusKnot[19, 2]]
Out[6]=   
BR[2, {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}]
In[7]:=
alex = Alexander[TorusKnot[19, 2]][t]
Out[7]=   
      -9    -8    -7    -6    -5    -4    -3    -2   1        2    3    4
-1 + t   - t   + t   - t   + t   - t   + t   - t   + - + t - t  + t  - t  + 
                                                     t
 
     5    6    7    8    9
>   t  - t  + t  - t  + t
In[8]:=
Conway[TorusKnot[19, 2]][z]
Out[8]=   
        2        4        6         8         10        12        14       16
1 + 45 z  + 330 z  + 924 z  + 1287 z  + 1001 z   + 455 z   + 120 z   + 17 z   + 
 
     18
>   z
In[9]:=
Select[AllKnots[], (alex === Alexander[#][t])&]
Out[9]=   
{}
In[10]:=
{KnotDet[TorusKnot[19, 2]], KnotSignature[TorusKnot[19, 2]]}
Out[10]=   
{19, 18}
In[11]:=
J=Jones[TorusKnot[19, 2]][q]
Out[11]=   
 9    11    12    13    14    15    16    17    18    19    20    21    22
q  + q   - q   + q   - q   + q   - q   + q   - q   + q   - q   + q   - q   + 
 
     23    24    25    26    27    28
>   q   - q   + q   - q   + q   - q
In[12]:=
Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]
Out[12]=   
{}
In[13]:=
A2Invariant[TorusKnot[19, 2]][q]
Out[13]=   
NotAvailable
In[14]:=
Kauffman[TorusKnot[19, 2]][a, z]
Out[14]=   
NotAvailable
In[15]:=
{Vassiliev[2][TorusKnot[19, 2]], Vassiliev[3][TorusKnot[19, 2]]}
Out[15]=   
{45, 285}
In[16]:=
Kh[TorusKnot[19, 2]][q, t]
Out[16]=   
 17    19    21  2    25  3    25  4    29  5    29  6    33  7    33  8
q   + q   + q   t  + q   t  + q   t  + q   t  + q   t  + q   t  + q   t  + 
 
     37  9    37  10    41  11    41  12    45  13    45  14    49  15
>   q   t  + q   t   + q   t   + q   t   + q   t   + q   t   + q   t   + 
 
     49  16    53  17    53  18    57  19
>   q   t   + q   t   + q   t   + q   t


Dror Bar-Natan: The Knot Atlas: Torus Knots: The Torus Knot T(19,2)
T(17,2)
T(17,2)
T(10,3)
T(10,3)