8 4: Difference between revisions
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{{Knot Navigation Links|ext=gif}} |
{{Knot Navigation Links|ext=gif}} |
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{{Vassiliev Invariants}} |
{{Vassiliev Invariants}} |
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{{Khovanov Homology|table=<table border=1> |
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The coefficients of the monomials <math>t^rq^j</math> are shown, along with their alternating sums <math>\chi</math> (fixed <math>j</math>, alternation over <math>r</math>). The squares with <font class=HLYellow>yellow</font> highlighting are those on the "critical diagonals", where <math>j-2r=s+1</math> or <math>j-2r=s+1</math>, where <math>s=</math>{{Data:{{PAGENAME}}/Signature}} is the signature of {{PAGENAME}}. Nonzero entries off the critical diagonals (if any exist) are highlighted in <font class=HLRed>red</font>. |
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<center><table border=1> |
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<td width=15.3846%><table cellpadding=0 cellspacing=0> |
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<tr align=center><td>-9</td><td bgcolor=yellow> </td><td bgcolor=yellow>1</td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td>-1</td></tr> |
<tr align=center><td>-9</td><td bgcolor=yellow> </td><td bgcolor=yellow>1</td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td>-1</td></tr> |
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<tr align=center><td>-11</td><td bgcolor=yellow>1</td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td>1</td></tr> |
<tr align=center><td>-11</td><td bgcolor=yellow>1</td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td>1</td></tr> |
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</table> |
</table>}} |
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{{Computer Talk Header}} |
{{Computer Talk Header}} |
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q t + 2 q t + q t + q t</nowiki></pre></td></tr> |
q t + 2 q t + q t + q t</nowiki></pre></td></tr> |
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</table> |
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[[Category:Knot Page]] |
Revision as of 20:05, 28 August 2005
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![]() |
Visit 8 4's page at the Knot Server (KnotPlot driven, includes 3D interactive images!)
Visit 8 4's page at Knotilus! Visit 8 4's page at the original Knot Atlas! |
Knot presentations
Planar diagram presentation | X6271 X14,10,15,9 X10,3,11,4 X2,13,3,14 X12,5,13,6 X16,8,1,7 X4,11,5,12 X8,16,9,15 |
Gauss code | 1, -4, 3, -7, 5, -1, 6, -8, 2, -3, 7, -5, 4, -2, 8, -6 |
Dowker-Thistlethwaite code | 6 10 12 16 14 4 2 8 |
Conway Notation | [413] |
Three dimensional invariants
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Four dimensional invariants
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Polynomial invariants
A1 Invariants.
Weight | Invariant |
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1 | |
2 | |
3 | |
4 | |
5 | |
6 |
A2 Invariants.
Weight | Invariant |
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1,0 | |
1,1 | |
2,0 | |
3,0 | Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle q^{72}+q^{66}+q^{64}+q^{62}-2 q^{60}-q^{58}-q^{54}-2 q^{52}-3 q^{50}+q^{48}+3 q^{46}-4 q^{42}-4 q^{40}+3 q^{38}+6 q^{36}+4 q^{34}-q^{32}+3 q^{28}+3 q^{26}+q^{24}-2 q^{22}+q^{18}-q^{14}-2 q^8-5 q^6-3 q^4-q^2-1-3 q^{-2} -3 q^{-4} +2 q^{-6} +5 q^{-8} +6 q^{-10} +2 q^{-12} +3 q^{-14} +5 q^{-16} +6 q^{-18} +3 q^{-20} -2 q^{-22} -4 q^{-24} -3 q^{-26} - q^{-28} -2 q^{-32} -3 q^{-34} -2 q^{-36} +2 q^{-40} + q^{-42} - q^{-46} + q^{-50} + q^{-52} + q^{-54} } |
A3 Invariants.
Weight | Invariant |
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0,1,0 | Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle q^{36}-q^{34}-q^{32}+2 q^{30}-q^{26}+2 q^{24}-q^{20}+q^{18}+q^{16}+q^{12}+q^{10}-2 q^6-q^4+q^2-2+ q^{-4} - q^{-6} + q^{-10} + q^{-14} +2 q^{-16} + q^{-20} } |
1,0,0 | Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle q^{21}+q^{17}+q^{13}+q^9-q^5-q^3-2 q- q^{-1} - q^{-3} + q^{-5} + q^{-7} +2 q^{-9} + q^{-11} + q^{-13} } |
A4 Invariants.
Weight | Invariant |
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0,1,0,0 | Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle q^{46}-q^{42}+q^{38}+q^{36}+q^{32}+2 q^{30}-q^{26}-2 q^{20}+q^{10}+2 q^8+2 q^4+3 q^2+1-2 q^{-2} - q^{-4} -2 q^{-6} -4 q^{-8} -3 q^{-10} - q^{-12} + q^{-14} + q^{-16} +3 q^{-18} +3 q^{-20} +2 q^{-22} + q^{-24} + q^{-26} } |
1,0,0,0 | Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle q^{26}+q^{22}+q^{20}+q^{16}+q^{12}-q^6-q^4-2 q^2-2- q^{-2} - q^{-4} + q^{-6} + q^{-8} +2 q^{-10} +2 q^{-12} + q^{-14} + q^{-16} } |
B2 Invariants.
Weight | Invariant |
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0,1 | Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle q^{36}-q^{34}+q^{32}-2 q^{30}+2 q^{28}-q^{26}+2 q^{24}+q^{20}+q^{18}-q^{16}+2 q^{14}-3 q^{12}+3 q^{10}-4 q^8+2 q^6-3 q^4+q^2-2+ q^{-4} - q^{-6} +2 q^{-8} - q^{-10} +2 q^{-12} - q^{-14} +2 q^{-16} + q^{-20} } |
1,0 | Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle q^{58}-q^{54}-q^{52}+2 q^{48}+q^{46}-q^{44}-q^{42}+2 q^{38}-q^{34}-q^{32}+q^{30}+q^{28}-q^{24}+2 q^{20}+q^{18}-q^{16}-q^{14}+q^{12}-q^8-q^6+q^4+q^2-2 q^{-2} +2 q^{-6} + q^{-8} - q^{-10} -2 q^{-12} + q^{-16} + q^{-18} - q^{-20} - q^{-22} + q^{-24} +2 q^{-26} + q^{-34} } |
D4 Invariants.
Weight | Invariant |
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1,0,0,0 | Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle q^{50}-q^{48}-q^{44}+2 q^{42}-q^{40}+q^{38}-q^{36}+2 q^{34}+q^{30}+q^{24}+2 q^{20}-q^{18}+3 q^{16}-2 q^{14}+3 q^{12}-3 q^{10}+q^8-3 q^6-3 q^2- q^{-2} - q^{-4} - q^{-8} +2 q^{-10} +2 q^{-14} +3 q^{-18} +2 q^{-22} + q^{-26} } |
G2 Invariants.
Weight | Invariant |
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1,0 |
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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["8 4"];
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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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{ 19, -2 } |
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: | (-3, 1) |
V2,1 through V6,9: |
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V2,1 through V6,9 were provided by Petr Dunin-Barkowski <barkovs@itep.ru>, Andrey Smirnov <asmirnov@itep.ru>, and Alexei Sleptsov <sleptsov@itep.ru> and uploaded on October 2010 by User:Drorbn. Note that they are normalized differently than V2 and V3.
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 -2 is the signature of 8 4. Nonzero entries off the critical diagonals (if any exist) are highlighted in red. |
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Integral Khovanov Homology
(db, data source) |
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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 17, 2005, 14:44:34)... | |
In[2]:= | Crossings[Knot[8, 4]] |
Out[2]= | 8 |
In[3]:= | PD[Knot[8, 4]] |
Out[3]= | PD[X[6, 2, 7, 1], X[14, 10, 15, 9], X[10, 3, 11, 4], X[2, 13, 3, 14], X[12, 5, 13, 6], X[16, 8, 1, 7], X[4, 11, 5, 12], X[8, 16, 9, 15]] |
In[4]:= | GaussCode[Knot[8, 4]] |
Out[4]= | GaussCode[1, -4, 3, -7, 5, -1, 6, -8, 2, -3, 7, -5, 4, -2, 8, -6] |
In[5]:= | BR[Knot[8, 4]] |
Out[5]= | BR[4, {-1, -1, -1, 2, -1, 2, 3, -2, 3}] |
In[6]:= | alex = Alexander[Knot[8, 4]][t] |
Out[6]= | 2 5 2 |
In[7]:= | Conway[Knot[8, 4]][z] |
Out[7]= | 2 4 1 - 3 z - 2 z |
In[8]:= | Select[AllKnots[], (alex === Alexander[#][t])&] |
Out[8]= | {Knot[8, 4]} |
In[9]:= | {KnotDet[Knot[8, 4]], KnotSignature[Knot[8, 4]]} |
Out[9]= | {19, -2} |
In[10]:= | J=Jones[Knot[8, 4]][q] |
Out[10]= | -5 2 3 3 3 2 3 |
In[11]:= | Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&] |
Out[11]= | {Knot[8, 4]} |
In[12]:= | A2Invariant[Knot[8, 4]][q] |
Out[12]= | -16 -10 -6 -4 -2 2 4 6 8 10 -1 + q + q + q - q - q - q + q + q + q + q |
In[13]:= | Kauffman[Knot[8, 4]][a, z] |
Out[13]= | 22 4 z 3 2 7 z 2 2 4 2 |
In[14]:= | {Vassiliev[2][Knot[8, 4]], Vassiliev[3][Knot[8, 4]]} |
Out[14]= | {0, 1} |
In[15]:= | Kh[Knot[8, 4]][q, t] |
Out[15]= | 2 2 1 1 1 2 1 1 2 2 t |