T(27,2)
[[Image:T(9,4).{{{ext}}}|80px|link=T(9,4)]] |
[[Image:T(7,5).{{{ext}}}|80px|link=T(7,5)]] |
Visit T(27,2)'s page at Knotilus!
Visit T(27,2)'s page at the original Knot Atlas!
Knot presentations
Planar diagram 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} |
Dowker-Thistlethwaite code | 28 30 32 34 36 38 40 42 44 46 48 50 52 54 2 4 6 8 10 12 14 16 18 20 22 24 26 |
Polynomial invariants
Polynomial invariants
KnotTheory`
, as shown in the (simulated) Mathematica session below. Your input (in red) is realistic; all else should have the same content as in a real mathematica session, but with different formatting. This Mathematica session is also available (albeit only for the knot 5_2) as the notebook PolynomialInvariantsSession.nb.
(The path below may be different on your system, and possibly also the KnotTheory` date)
In[1]:=
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AppendTo[$Path, "C:/drorbn/projects/KAtlas/"];
<< KnotTheory`
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Loading KnotTheory` version of August 31, 2006, 11:25:27.5625.
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In[3]:=
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K = Knot["T(27,2)"];
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In[4]:=
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Alexander[K][t]
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KnotTheory::loading: Loading precomputed data in PD4Knots`.
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Out[4]=
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In[5]:=
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Conway[K][z]
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Out[5]=
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In[6]:=
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Alexander[K, 2][t]
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KnotTheory::credits: The program Alexander[K, r] to compute Alexander ideals was written by Jana Archibald at the University of Toronto in the summer of 2005.
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Out[6]=
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In[7]:=
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{KnotDet[K], KnotSignature[K]}
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Out[7]=
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{ 27, 26 } |
In[8]:=
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Jones[K][q]
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KnotTheory::loading: Loading precomputed data in Jones4Knots`.
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Out[8]=
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In[9]:=
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HOMFLYPT[K][a, z]
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KnotTheory::credits: The HOMFLYPT program was written by Scott Morrison.
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Out[9]=
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In[10]:=
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Kauffman[K][a, z]
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KnotTheory::loading: Loading precomputed data in Kauffman4Knots`.
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Out[10]=
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Vassiliev invariants
V2 and V3 | {0, 819}) |
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 26 is the signature of T(27,2). Nonzero entries off the critical diagonals (if any exist) are highlighted in red.
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0 | 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 | χ | |||||||||
81 | 1 | -1 | ||||||||||||||||||||||||||||||||||||
79 | 0 | |||||||||||||||||||||||||||||||||||||
77 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
75 | 0 | |||||||||||||||||||||||||||||||||||||
73 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
71 | 0 | |||||||||||||||||||||||||||||||||||||
69 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
67 | 0 | |||||||||||||||||||||||||||||||||||||
65 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
63 | 0 | |||||||||||||||||||||||||||||||||||||
61 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
59 | 0 | |||||||||||||||||||||||||||||||||||||
57 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
55 | 0 | |||||||||||||||||||||||||||||||||||||
53 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
51 | 0 | |||||||||||||||||||||||||||||||||||||
49 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
47 | 0 | |||||||||||||||||||||||||||||||||||||
45 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
43 | 0 | |||||||||||||||||||||||||||||||||||||
41 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
39 | 0 | |||||||||||||||||||||||||||||||||||||
37 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
35 | 0 | |||||||||||||||||||||||||||||||||||||
33 | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||
31 | 0 | |||||||||||||||||||||||||||||||||||||
29 | 1 | 1 | ||||||||||||||||||||||||||||||||||||
27 | 1 | 1 | ||||||||||||||||||||||||||||||||||||
25 | 1 | 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 19, 2005, 13:11:25)... | |
In[2]:= | Crossings[TorusKnot[27, 2]] |
Out[2]= | 27 |
In[3]:= | PD[TorusKnot[27, 2]] |
Out[3]= | 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[4]:= | GaussCode[TorusKnot[27, 2]] |
Out[4]= | 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[5]:= | BR[TorusKnot[27, 2]] |
Out[5]= | 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[6]:= | alex = Alexander[TorusKnot[27, 2]][t] |
Out[6]= | -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 |
In[7]:= | Conway[TorusKnot[27, 2]][z] |
Out[7]= | 2 4 6 8 10 12 |
In[8]:= | Select[AllKnots[], (alex === Alexander[#][t])&] |
Out[8]= | {} |
In[9]:= | {KnotDet[TorusKnot[27, 2]], KnotSignature[TorusKnot[27, 2]]} |
Out[9]= | {27, 26} |
In[10]:= | J=Jones[TorusKnot[27, 2]][q] |
Out[10]= | 13 15 16 17 18 19 20 21 22 23 24 25 |
In[11]:= | Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&] |
Out[11]= | {} |
In[12]:= | A2Invariant[TorusKnot[27, 2]][q] |
Out[12]= | NotAvailable |
In[13]:= | Kauffman[TorusKnot[27, 2]][a, z] |
Out[13]= | NotAvailable |
In[14]:= | {Vassiliev[2][TorusKnot[27, 2]], Vassiliev[3][TorusKnot[27, 2]]} |
Out[14]= | {0, 819} |
In[15]:= | Kh[TorusKnot[27, 2]][q, t] |
Out[15]= | 25 27 29 2 33 3 33 4 37 5 37 6 41 7 |