3 1: Difference between revisions
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{{Knot Presentations}} |
{{Knot Presentations}} |
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<center><table border=1 cellpadding=10><tr align=center valign=top> |
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<td> |
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[[Braid Representatives|Minimum Braid Representative]]: |
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<table cellspacing=0 cellpadding=0 border=0> |
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<tr><td>[[Image:BraidPart3.gif]][[Image:BraidPart3.gif]][[Image:BraidPart3.gif]]</td></tr> |
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<tr><td>[[Image:BraidPart4.gif]][[Image:BraidPart4.gif]][[Image:BraidPart4.gif]]</td></tr> |
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</table> |
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[[Invariants from Braid Theory|Length]] is 3, width is 2. |
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[[Invariants from Braid Theory|Braid index]] is 2. |
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</td> |
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<td> |
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[[Lightly Documented Features|A Morse Link Presentation]]: |
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[[Image:{{PAGENAME}}_ML.gif]] |
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</td> |
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</tr></table></center> |
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{{3D Invariants}} |
{{3D Invariants}} |
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{{4D Invariants}} |
{{4D Invariants}} |
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{{Polynomial Invariants}} |
{{Polynomial Invariants}} |
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=== "Similar" Knots (within the Atlas) === |
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Same [[The Alexander-Conway Polynomial|Alexander/Conway Polynomial]]: |
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{...} |
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Same [[The Jones Polynomial|Jones Polynomial]] (up to mirroring, <math>q\leftrightarrow q^{-1}</math>): |
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{...} |
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{{Vassiliev Invariants}} |
{{Vassiliev Invariants}} |
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<tr align=center><td>-9</td><td bgcolor=yellow>1</td><td> </td><td> </td><td> </td><td>-1</td></tr> |
<tr align=center><td>-9</td><td bgcolor=yellow>1</td><td> </td><td> </td><td> </td><td>-1</td></tr> |
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</table>}} |
</table>}} |
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{{Display Coloured Jones|J2=<math> q^{-2} + q^{-5} - q^{-7} + q^{-8} - q^{-9} - q^{-10} + q^{-11} </math>|J3=<math> q^{-3} + q^{-7} - q^{-10} + q^{-11} - q^{-13} - q^{-14} + q^{-15} - q^{-17} + q^{-19} + q^{-20} - q^{-21} </math>|J4=<math> q^{-4} + q^{-9} - q^{-13} + q^{-14} - q^{-17} - q^{-18} + q^{-19} - q^{-22} - q^{-23} +2 q^{-24} - q^{-28} +2 q^{-29} - q^{-32} - q^{-33} + q^{-34} </math>|J5=<math> q^{-5} + q^{-11} - q^{-16} + q^{-17} - q^{-21} - q^{-22} + q^{-23} - q^{-27} - q^{-28} + q^{-29} + q^{-30} - q^{-33} + q^{-35} + q^{-36} - q^{-39} + q^{-42} - q^{-44} - q^{-45} + q^{-48} + q^{-49} - q^{-50} </math>|J6=<math> q^{-6} + q^{-13} - q^{-19} + q^{-20} - q^{-25} - q^{-26} + q^{-27} - q^{-32} - q^{-33} + q^{-34} + q^{-36} - q^{-39} - q^{-40} +2 q^{-41} + q^{-43} - q^{-46} - q^{-47} +2 q^{-48} - q^{-53} -2 q^{-54} +2 q^{-55} - q^{-60} - q^{-61} +2 q^{-62} + q^{-64} - q^{-67} - q^{-68} + q^{-69} </math>|J7=<math> q^{-7} + q^{-15} - q^{-22} + q^{-23} - q^{-29} - q^{-30} + q^{-31} - q^{-37} - q^{-38} + q^{-39} + q^{-42} - q^{-45} - q^{-46} + q^{-47} + q^{-48} + q^{-50} - q^{-53} - q^{-54} + q^{-55} + q^{-56} + q^{-58} - q^{-59} - q^{-61} - q^{-62} + q^{-63} + q^{-66} - q^{-67} - q^{-69} - q^{-70} + q^{-71} + q^{-73} + q^{-74} - q^{-75} - q^{-78} + q^{-79} + q^{-81} + q^{-82} - q^{-83} - q^{-84} - q^{-86} + q^{-89} + q^{-90} - q^{-91} </math>}} |
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{{Computer Talk Header}} |
{{Computer Talk Header}} |
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<td align=left><pre style="color: red; border: 0px; padding: 0em"><< KnotTheory`</pre></td> |
<td align=left><pre style="color: red; border: 0px; padding: 0em"><< KnotTheory`</pre></td> |
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</tr> |
</tr> |
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<tr valign=top><td colspan=2><pre style="border: 0px; padding: 0em">Loading KnotTheory` (version of August |
<tr valign=top><td colspan=2><pre style="border: 0px; padding: 0em">Loading KnotTheory` (version of August 29, 2005, 15:27:48)...</pre></td></tr> |
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<tr valign=top><td><pre |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[2]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>PD[Knot[3, 1]]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[2]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki>PD[X[1, 4, 2, 5], X[3, 6, 4, 1], X[5, 2, 6, 3]]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[ |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[3]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>GaussCode[Knot[3, 1]]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[ |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[3]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki>GaussCode[-1, 3, -2, 1, -3, 2]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[5]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki>BR[2, {-1, -1, -1}]</nowiki></pre></td></tr> |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[5]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki>BR[2, {-1, -1, -1}]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[6]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>{First[br], Crossings[br]}</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[8]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>Show[DrawMorseLink[Knot[3, 1]]]</nowiki></pre></td></tr><tr><td></td><td align=left>[[Image:3_1_ML.gif]]</td></tr><tr valign=top><td><tt><font color=blue>Out[8]=</font></tt><td><tt><font color=black>-Graphics-</font></tt></td></tr> |
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⚫ | <tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[9]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>(#[Knot[3, 1]]&) /@ {SymmetryType, UnknottingNumber, ThreeGenus, BridgeIndex, SuperBridgeIndex, NakanishiIndex}</nowiki></pre></td></tr> |
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-1 + - + t |
-1 + - + t |
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t</nowiki></pre></td></tr> |
t</nowiki></pre></td></tr> |
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<tr valign=top><td><pre |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[11]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>Conway[Knot[3, 1]][z]</nowiki></pre></td></tr> |
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1 + z</nowiki></pre></td></tr> |
1 + z</nowiki></pre></td></tr> |
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<tr valign=top><td><pre |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[12]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>Select[AllKnots[], (alex === Alexander[#][t])&]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[12]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki>{Knot[3, 1]}</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[ |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[13]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>{KnotDet[Knot[3, 1]], KnotSignature[Knot[3, 1]]}</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[ |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[13]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki>{3, -2}</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[14]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki> -4 -3 1 |
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-q + q + - |
-q + q + - |
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q</nowiki></pre></td></tr> |
q</nowiki></pre></td></tr> |
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<tr valign=top><td><pre |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[15]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[15]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki>{Knot[3, 1]}</nowiki></pre></td></tr> |
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<math>\textrm{Include}(\textrm{ColouredJonesM.mhtml})</math> |
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<tr valign=top><td><pre |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[16]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>A2Invariant[Knot[3, 1]][q]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[16]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki> -14 -12 -8 2 -4 -2 |
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-q - q + q + -- + q + q |
-q - q + q + -- + q + q |
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6 |
6 |
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q</nowiki></pre></td></tr> |
q</nowiki></pre></td></tr> |
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<tr valign=top><td><pre |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[17]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>HOMFLYPT[Knot[3, 1]][a, z]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[17]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki> 2 4 2 2 |
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2 a - a + a z</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[18]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>Kauffman[Knot[3, 1]][a, z]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[18]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki> 2 4 3 5 2 2 4 2 |
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-2 a - a + a z + a z + a z + a z</nowiki></pre></td></tr> |
-2 a - a + a z + a z + a z + a z</nowiki></pre></td></tr> |
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<tr valign=top><td><pre |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[19]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>{Vassiliev[2][Knot[3, 1]], Vassiliev[3][Knot[3, 1]]}</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: |
<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[19]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki>{1, -1}</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[20]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>Kh[Knot[3, 1]][q, t]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[20]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki> -3 1 1 1 |
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q + - + ----- + ----- |
q + - + ----- + ----- |
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q 9 3 5 2 |
q 9 3 5 2 |
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q t q t</nowiki></pre></td></tr> |
q t q t</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>In[21]:=</nowiki></pre></td><td><pre style="color: red; border: 0px; padding: 0em"><nowiki>ColouredJones[Knot[3, 1], 2][q]</nowiki></pre></td></tr> |
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<tr valign=top><td><pre style="color: blue; border: 0px; padding: 0em"><nowiki>Out[21]= </nowiki></pre></td><td><pre style="color: black; border: 0px; padding: 0em"><nowiki> -11 -10 -9 -8 -7 -5 -2 |
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q - q - q + q - q + q + q</nowiki></pre></td></tr> |
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</table> |
</table> |
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See/edit the [[Rolfsen_Splice_Template]]. |
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[[Category:Knot Page]] |
[[Category:Knot Page]] |
Revision as of 17:04, 29 August 2005
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Visit 3 1's page at the Knot Server (KnotPlot driven, includes 3D interactive images!)
Visit 3 1's page at Knotilus! Visit 3 1's page at the original Knot Atlas! 3_1 is also known as "The Trefoil Knot", after plants of the genus Trifolium, which have compound trifoliate leaves, and as the "Overhand Knot". See also T(3,2). |
The trefoil is perhaps the easiest knot to find in "nature", and is topologically equivalent to the interlaced form of the common Christian and pagan "triquetra" symbol [12]:
Knot presentations
Planar diagram presentation | X1425 X3641 X5263 |
Gauss code | -1, 3, -2, 1, -3, 2 |
Dowker-Thistlethwaite code | 4 6 2 |
Conway Notation | [3] |
Length is 3, width is 2. Braid index is 2. |
Three dimensional invariants
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[edit Notes for 3 1's three dimensional invariants] The rope length of the trefoil is known to be no more than 16.372, by numerical experiments, while the sharpest known lower bound (actually applicable to all non-trivial knots) is 15.66. The trefoil is a fibered knot! A java applet demonstrating it, written by Robert Barrington Leigh at the University of Toronto, is here. |
Four dimensional invariants
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Polynomial invariants
The braid index of 3_1 is only 2, so it's easy to calculate lots of quantum invariants. A1 Invariants.
Weight | Invariant |
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1 | |
2 | |
3 | |
4 | |
5 | |
6 | |
8 |
A2 Invariants.
Weight | Invariant |
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0,1 | |
0,2 | |
1,0 | |
1,1 | |
2,0 | |
3,0 |
A3 Invariants.
Weight | Invariant |
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0,0,1 | |
0,1,0 | |
1,0,0 | |
1,0,1 |
A4 Invariants.
Weight | Invariant |
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0,0,0,1 | |
0,1,0,0 | |
1,0,0,0 |
A5 Invariants.
Weight | Invariant |
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0,0,0,0,1 | |
1,0,0,0,0 |
A6 Invariants.
Weight | Invariant |
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0,0,0,0,0,1 | |
1,0,0,0,0,0 |
B2 Invariants.
Weight | Invariant |
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0,1 | |
1,0 |
B3 Invariants.
Weight | Invariant |
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1,0,0 |
B4 Invariants.
Weight | Invariant |
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1,0,0,0 |
B5 Invariants.
Weight | Invariant |
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1,0,0,0,0 |
C3 Invariants.
Weight | Invariant |
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1,0,0 |
C4 Invariants.
Weight | Invariant |
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1,0,0,0 |
D4 Invariants.
Weight | Invariant |
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0,1,0,0 | |
1,0,0,0 |
G2 Invariants.
Weight | Invariant |
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0,1 | |
1,0 |
.
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["3 1"];
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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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{ 3, -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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"Similar" Knots (within the Atlas)
Same Alexander/Conway Polynomial: {...}
Same Jones Polynomial (up to mirroring, ): {...}
Vassiliev invariants
V2 and V3: | (1, -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 3 1. 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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The Coloured Jones Polynomials
2 | |
3 | |
4 | |
5 | |
6 | |
7 |
Computer Talk
Much of the above data can be recomputed by Mathematica using the package KnotTheory`
. See A Sample KnotTheory` Session.
See/edit the Rolfsen_Splice_Template.