8 5: Difference between revisions

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{{Knot Navigation Links|ext=gif}}
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{{Rolfsen Knot Page Header|n=8|k=5|KnotilusURL=http://srankin.math.uwo.ca/cgi-bin/retrieve.cgi/1,-3,2,-6,5,-1,3,-2,4,-8,7,-5,6,-4,8,-7/goTop.html}}
{| align=left
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|{{Rolfsen Knot Site Links|n=8|k=5|KnotilusURL=http://srankin.math.uwo.ca/cgi-bin/retrieve.cgi/1,-3,2,-6,5,-1,3,-2,4,-8,7,-5,6,-4,8,-7/goTop.html}}
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{{Vassiliev Invariants}}
{{Vassiliev Invariants}}


===[[Khovanov Homology]]===
{{Khovanov Homology|table=<table border=1>

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>.

<center><table border=1>
<tr align=center>
<tr align=center>
<td width=15.3846%><table cellpadding=0 cellspacing=0>
<td width=15.3846%><table cellpadding=0 cellspacing=0>
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<tr align=center><td>1</td><td bgcolor=yellow>&nbsp;</td><td bgcolor=yellow>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>0</td></tr>
<tr align=center><td>1</td><td bgcolor=yellow>&nbsp;</td><td bgcolor=yellow>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>0</td></tr>
<tr align=center><td>-1</td><td bgcolor=yellow>1</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>1</td></tr>
<tr align=center><td>-1</td><td bgcolor=yellow>1</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>1</td></tr>
</table></center>
</table>}}

{{Computer Talk Header}}
{{Computer Talk Header}}


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2 q t + q t + 2 q t + q t + q t + q t</nowiki></pre></td></tr>
2 q t + q t + 2 q t + q t + q t + q t</nowiki></pre></td></tr>
</table>
</table>

[[Category:Knot Page]]

Revision as of 19:10, 28 August 2005

8 4.gif

8_4

8 6.gif

8_6

8 5.gif Visit 8 5's page at the Knot Server (KnotPlot driven, includes 3D interactive images!)

Visit 8 5's page at Knotilus!

Visit 8 5's page at the original Knot Atlas!

8 5 is also known as the pretzel knot P(3,3,2).



Symmetric alternative representation
Pretzel P(3,3,2) form Photo 01-09-2017 besalu.jpg.
Sum of 8.5 ; church of Besalu, Catalogna

Knot presentations

Planar diagram presentation X6271 X8493 X2837 X14,10,15,9 X12,5,13,6 X4,13,5,14 X16,12,1,11 X10,16,11,15
Gauss code 1, -3, 2, -6, 5, -1, 3, -2, 4, -8, 7, -5, 6, -4, 8, -7
Dowker-Thistlethwaite code 6 8 12 2 14 16 4 10
Conway Notation [3,3,2]

Three dimensional invariants

Symmetry type Reversible
Unknotting number 2
3-genus 3
Bridge index 3
Super bridge index [math]\displaystyle{ \{4,6\} }[/math]
Nakanishi index 1
Maximal Thurston-Bennequin number [1][-11]
Hyperbolic Volume 6.99719
A-Polynomial See Data:8 5/A-polynomial

[edit Notes for 8 5's three dimensional invariants]

Four dimensional invariants

Smooth 4 genus [math]\displaystyle{ 2 }[/math]
Topological 4 genus [math]\displaystyle{ 2 }[/math]
Concordance genus [math]\displaystyle{ 3 }[/math]
Rasmussen s-Invariant -4

[edit Notes for 8 5's four dimensional invariants]

Polynomial invariants

Alexander polynomial [math]\displaystyle{ -t^3+3 t^2-4 t+5-4 t^{-1} +3 t^{-2} - t^{-3} }[/math]
Conway polynomial [math]\displaystyle{ -z^6-3 z^4-z^2+1 }[/math]
2nd Alexander ideal (db, data sources) [math]\displaystyle{ \{1\} }[/math]
Determinant and Signature { 21, 4 }
Jones polynomial [math]\displaystyle{ q^8-2 q^7+3 q^6-4 q^5+3 q^4-3 q^3+3 q^2-q+1 }[/math]
HOMFLY-PT polynomial (db, data sources) [math]\displaystyle{ -z^6 a^{-4} +z^4 a^{-2} -5 z^4 a^{-4} +z^4 a^{-6} +4 z^2 a^{-2} -8 z^2 a^{-4} +3 z^2 a^{-6} +4 a^{-2} -5 a^{-4} +2 a^{-6} }[/math]
Kauffman polynomial (db, data sources) [math]\displaystyle{ z^7 a^{-3} +z^7 a^{-5} +z^6 a^{-2} +4 z^6 a^{-4} +3 z^6 a^{-6} -3 z^5 a^{-3} +z^5 a^{-5} +4 z^5 a^{-7} -5 z^4 a^{-2} -15 z^4 a^{-4} -7 z^4 a^{-6} +3 z^4 a^{-8} -10 z^3 a^{-5} -8 z^3 a^{-7} +2 z^3 a^{-9} +8 z^2 a^{-2} +15 z^2 a^{-4} +4 z^2 a^{-6} -2 z^2 a^{-8} +z^2 a^{-10} +3 z a^{-3} +7 z a^{-5} +4 z a^{-7} -4 a^{-2} -5 a^{-4} -2 a^{-6} }[/math]
The A2 invariant [math]\displaystyle{ 1+ q^{-2} +2 q^{-4} +2 q^{-6} -3 q^{-12} - q^{-14} - q^{-16} + q^{-20} + q^{-24} }[/math]
The G2 invariant [math]\displaystyle{ q^{-2} +3 q^{-6} -2 q^{-8} +2 q^{-10} + q^{-12} -2 q^{-14} +7 q^{-16} -5 q^{-18} +5 q^{-20} + q^{-22} -2 q^{-24} +8 q^{-26} -5 q^{-28} +5 q^{-30} +2 q^{-32} -2 q^{-34} +3 q^{-36} -3 q^{-38} +2 q^{-42} -4 q^{-44} +2 q^{-46} -4 q^{-48} -2 q^{-50} +2 q^{-52} -9 q^{-54} +4 q^{-56} -7 q^{-58} + q^{-62} -7 q^{-64} +7 q^{-66} -7 q^{-68} +4 q^{-70} +2 q^{-72} -5 q^{-74} +5 q^{-76} -2 q^{-78} + q^{-80} +4 q^{-82} -2 q^{-84} +3 q^{-86} + q^{-88} - q^{-90} +4 q^{-92} -4 q^{-94} +3 q^{-96} -2 q^{-100} +3 q^{-102} -3 q^{-104} +3 q^{-106} - q^{-108} + q^{-110} -3 q^{-114} +2 q^{-116} -2 q^{-118} +2 q^{-120} - q^{-122} - q^{-128} + q^{-130} - q^{-132} + q^{-134} }[/math]

Vassiliev invariants

V2 and V3: (-1, -3)
V2,1 through V6,9:
V2,1 V3,1 V4,1 V4,2 V4,3 V5,1 V5,2 V5,3 V5,4 V6,1 V6,2 V6,3 V6,4 V6,5 V6,6 V6,7 V6,8 V6,9
[math]\displaystyle{ -4 }[/math] [math]\displaystyle{ -24 }[/math] [math]\displaystyle{ 8 }[/math] [math]\displaystyle{ -\frac{62}{3} }[/math] [math]\displaystyle{ \frac{86}{3} }[/math] [math]\displaystyle{ 96 }[/math] [math]\displaystyle{ 208 }[/math] [math]\displaystyle{ 96 }[/math] [math]\displaystyle{ 104 }[/math] [math]\displaystyle{ -\frac{32}{3} }[/math] [math]\displaystyle{ 288 }[/math] [math]\displaystyle{ \frac{248}{3} }[/math] [math]\displaystyle{ -\frac{344}{3} }[/math] [math]\displaystyle{ \frac{31409}{30} }[/math] [math]\displaystyle{ \frac{834}{5} }[/math] [math]\displaystyle{ \frac{16618}{45} }[/math] [math]\displaystyle{ \frac{2095}{18} }[/math] [math]\displaystyle{ -\frac{1231}{30} }[/math]

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 [math]\displaystyle{ t^rq^j }[/math] are shown, along with their alternating sums [math]\displaystyle{ \chi }[/math] (fixed [math]\displaystyle{ j }[/math], alternation over [math]\displaystyle{ r }[/math]). The squares with yellow highlighting are those on the "critical diagonals", where [math]\displaystyle{ j-2r=s+1 }[/math] or [math]\displaystyle{ j-2r=s-1 }[/math], where [math]\displaystyle{ s= }[/math]4 is the signature of 8 5. Nonzero entries off the critical diagonals (if any exist) are highlighted in red.   
\ r
  \  
j \
-2-10123456χ
17        11
15       1 -1
13      21 1
11     21  -1
9    12   -1
7   22    0
5  11     0
3 13      2
1         0
-11        1
Integral Khovanov Homology

(db, data source)

  
[math]\displaystyle{ \dim{\mathcal G}_{2r+i}\operatorname{KH}^r_{\mathbb Z} }[/math] [math]\displaystyle{ i=3 }[/math] [math]\displaystyle{ i=5 }[/math]
[math]\displaystyle{ r=-2 }[/math] [math]\displaystyle{ {\mathbb Z} }[/math]
[math]\displaystyle{ r=-1 }[/math] [math]\displaystyle{ {\mathbb Z}_2 }[/math] [math]\displaystyle{ {\mathbb Z} }[/math]
[math]\displaystyle{ r=0 }[/math] [math]\displaystyle{ {\mathbb Z}^{3} }[/math] [math]\displaystyle{ {\mathbb Z} }[/math]
[math]\displaystyle{ r=1 }[/math] [math]\displaystyle{ {\mathbb Z}\oplus{\mathbb Z}_2^{2} }[/math] [math]\displaystyle{ {\mathbb Z}^{2} }[/math]
[math]\displaystyle{ r=2 }[/math] [math]\displaystyle{ {\mathbb Z}^{2}\oplus{\mathbb Z}_2 }[/math] [math]\displaystyle{ {\mathbb Z} }[/math]
[math]\displaystyle{ r=3 }[/math] [math]\displaystyle{ {\mathbb Z}^{2}\oplus{\mathbb Z}_2^{2} }[/math] [math]\displaystyle{ {\mathbb Z}^{2} }[/math]
[math]\displaystyle{ r=4 }[/math] [math]\displaystyle{ {\mathbb Z}\oplus{\mathbb Z}_2^{2} }[/math] [math]\displaystyle{ {\mathbb Z}^{2} }[/math]
[math]\displaystyle{ r=5 }[/math] [math]\displaystyle{ {\mathbb Z}\oplus{\mathbb Z}_2 }[/math] [math]\displaystyle{ {\mathbb Z} }[/math]
[math]\displaystyle{ r=6 }[/math] [math]\displaystyle{ {\mathbb Z}_2 }[/math] [math]\displaystyle{ {\mathbb Z} }[/math]

Computer Talk

Much of the above data can be recomputed by Mathematica using the package KnotTheory`. See A Sample KnotTheory` Session.

[math]\displaystyle{ \textrm{Include}(\textrm{ColouredJonesM.mhtml}) }[/math]

In[1]:=    
<< KnotTheory`
Loading KnotTheory` (version of August 17, 2005, 14:44:34)...
In[2]:=
Crossings[Knot[8, 5]]
Out[2]=  
8
In[3]:=
PD[Knot[8, 5]]
Out[3]=  
PD[X[6, 2, 7, 1], X[8, 4, 9, 3], X[2, 8, 3, 7], X[14, 10, 15, 9], 
  X[12, 5, 13, 6], X[4, 13, 5, 14], X[16, 12, 1, 11], X[10, 16, 11, 15]]
In[4]:=
GaussCode[Knot[8, 5]]
Out[4]=  
GaussCode[1, -3, 2, -6, 5, -1, 3, -2, 4, -8, 7, -5, 6, -4, 8, -7]
In[5]:=
BR[Knot[8, 5]]
Out[5]=  
BR[3, {1, 1, 1, -2, 1, 1, 1, -2}]
In[6]:=
alex = Alexander[Knot[8, 5]][t]
Out[6]=  
     -3   3    4            2    3

5 - t + -- - - - 4 t + 3 t - t

          2   t
t
In[7]:=
Conway[Knot[8, 5]][z]
Out[7]=  
     2      4    6
1 - z  - 3 z  - z
In[8]:=
Select[AllKnots[], (alex === Alexander[#][t])&]
Out[8]=  
{Knot[8, 5], Knot[10, 141]}
In[9]:=
{KnotDet[Knot[8, 5]], KnotSignature[Knot[8, 5]]}
Out[9]=  
{21, 4}
In[10]:=
J=Jones[Knot[8, 5]][q]
Out[10]=  
           2      3      4      5      6      7    8
1 - q + 3 q  - 3 q  + 3 q  - 4 q  + 3 q  - 2 q  + q
In[11]:=
Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]
Out[11]=  
{Knot[8, 5]}
In[12]:=
A2Invariant[Knot[8, 5]][q]
Out[12]=  
     2      4      6      12    14    16    20    24
1 + q  + 2 q  + 2 q  - 3 q   - q   - q   + q   + q
In[13]:=
Kauffman[Knot[8, 5]][a, z]
Out[13]=  
                                  2       2      2       2      2

-2 5 4 4 z 7 z 3 z z 2 z 4 z 15 z 8 z -- - -- - -- + --- + --- + --- + --- - ---- + ---- + ----- + ---- +

6    4    2    7     5     3     10     8      6      4       2

a a a a a a a a a a a

    3      3       3      4      4       4      4      5    5      5
 2 z    8 z    10 z    3 z    7 z    15 z    5 z    4 z    z    3 z
 ---- - ---- - ----- + ---- - ---- - ----- - ---- + ---- + -- - ---- + 
   9      7      5       8      6      4       2      7     5     3
  a      a      a       a      a      a       a      a     a     a

    6      6    6    7    7
 3 z    4 z    z    z    z
 ---- + ---- + -- + -- + --
   6      4     2    5    3
a a a a a
In[14]:=
{Vassiliev[2][Knot[8, 5]], Vassiliev[3][Knot[8, 5]]}
Out[14]=  
{0, -3}
In[15]:=
Kh[Knot[8, 5]][q, t]
Out[15]=  
                    3
  3    5    1     q     5        7        7  2    9  2      9  3

3 q + q + ---- + -- + q t + 2 q t + 2 q t + q t + 2 q t +

              2   t
           q t

    11  3    11  4      13  4    13  5    15  5    17  6
2 q t + q t + 2 q t + q t + q t + q t