8 3

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8 2.gif

8_2

8 4.gif

8_4

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8 3 Quick Notes


8 3 Further Notes and Views

Knot presentations

Planar diagram presentation X6271 X14,10,15,9 X10,5,11,6 X12,3,13,4 X4,11,5,12 X2,13,3,14 X16,8,1,7 X8,16,9,15
Gauss code 1, -6, 4, -5, 3, -1, 7, -8, 2, -3, 5, -4, 6, -2, 8, -7
Dowker-Thistlethwaite code 6 12 10 16 14 4 2 8
Conway Notation [44]

Three dimensional invariants

Symmetry type Fully amphicheiral
Unknotting number 2
3-genus 1
Bridge index 2
Super bridge index 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 \{4,6\}}
Nakanishi index 1
Maximal Thurston-Bennequin number [-5][-5]
Hyperbolic Volume 5.23868
A-Polynomial See Data:8 3/A-polynomial

[edit Notes for 8 3's three dimensional invariants]

Four dimensional invariants

Smooth 4 genus 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 1}
Topological 4 genus
Concordance genus 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 1}
Rasmussen s-Invariant 0

[edit Notes for 8 3's four dimensional invariants]

Polynomial invariants

Alexander polynomial 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 -4 t+9-4 t^{-1} }
Conway polynomial 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 1-4 z^2}
2nd Alexander ideal (db, data sources) 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 \{1\}}
Determinant and Signature { 17, 0 }
Jones polynomial
HOMFLY-PT polynomial (db, data sources) 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 a^4-z^2 a^2-2 z^2-1-z^2 a^{-2} + a^{-4} }
Kauffman polynomial (db, data sources) 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 a z^7+z^7 a^{-1} +a^2 z^6+z^6 a^{-2} +2 z^6+a^3 z^5-4 a z^5-4 z^5 a^{-1} +z^5 a^{-3} +a^4 z^4-2 a^2 z^4-2 z^4 a^{-2} +z^4 a^{-4} -6 z^4-2 a^3 z^3+8 a z^3+8 z^3 a^{-1} -2 z^3 a^{-3} -3 a^4 z^2+a^2 z^2+z^2 a^{-2} -3 z^2 a^{-4} +8 z^2-4 a z-4 z a^{-1} +a^4+ a^{-4} -1}
The A2 invariant 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^{14}+q^{12}+q^8-q^4-1- q^{-4} + q^{-8} + q^{-12} + q^{-14} }
The G2 invariant 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^{66}+q^{62}-q^{60}+q^{58}+q^{56}-q^{54}+2 q^{52}-q^{50}+2 q^{48}-q^{46}+q^{42}-2 q^{40}+4 q^{38}-3 q^{36}+q^{34}+q^{32}-2 q^{30}+3 q^{28}-2 q^{26}+q^{24}+2 q^{22}-2 q^{20}+q^{18}-2 q^{14}+4 q^{12}-4 q^{10}+q^8-3 q^4+3 q^2-5+3 q^{-2} -3 q^{-4} + q^{-8} -4 q^{-10} +4 q^{-12} -2 q^{-14} + q^{-18} -2 q^{-20} +2 q^{-22} + q^{-24} -2 q^{-26} +3 q^{-28} -2 q^{-30} + q^{-32} + q^{-34} -3 q^{-36} +4 q^{-38} -2 q^{-40} + q^{-42} - q^{-46} +2 q^{-48} - q^{-50} +2 q^{-52} - q^{-54} + q^{-56} + q^{-58} - q^{-60} + q^{-62} + q^{-66} }

Vassiliev invariants

V2 and V3: (-4, 0)
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
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 -16} 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 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 128} 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 \frac{520}{3}} 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 \frac{200}{3}} 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 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 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 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 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 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 -\frac{8320}{3}} 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 -\frac{3200}{3}} 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 -\frac{37502}{15}} 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 \frac{6728}{15}} 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 \frac{2174}{9}} 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 -\frac{7262}{15}}

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 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 t^rq^j} are shown, along with their alternating sums 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 \chi} (fixed 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 j} , alternation over ). The squares with yellow highlighting are those on the "critical diagonals", where 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 j-2r=s+1} or 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 j-2r=s+1} , where 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 s=} 0 is the signature of 8 3. Nonzero entries off the critical diagonals (if any exist) are highlighted in red.

\ r
  \  
j \
-4-3-2-101234χ
9        11
7         0
5      21 1
3     1   -1
1    22   0
-1   22    0
-3   1     -1
-5 12      1
-7         0
-91        1

Computer Talk

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

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 \textrm{Include}(\textrm{ColouredJonesM.mhtml})}

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

9 - - - 4 t

t
In[7]:=
Conway[Knot[8, 3]][z]
Out[7]=  
       2
1 - 4 z
In[8]:=
Select[AllKnots[], (alex === Alexander[#][t])&]
Out[8]=  
{Knot[8, 3], Knot[10, 1]}
In[9]:=
{KnotDet[Knot[8, 3]], KnotSignature[Knot[8, 3]]}
Out[9]=  
{17, 0}
In[10]:=
J=Jones[Knot[8, 3]][q]
Out[10]=  
     -4    -3   2    3            2    3    4

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

                2   q
q
In[11]:=
Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]
Out[11]=  
{Knot[8, 3]}
In[12]:=
A2Invariant[Knot[8, 3]][q]
Out[12]=  
      -14    -12    -8    -4    4    8    12    14
-1 + q    + q    + q   - q   - q  + q  + q   + q
In[13]:=
Kauffman[Knot[8, 3]][a, z]
Out[13]=  
                                        2    2
     -4    4   4 z              2   3 z    z     2  2      4  2

-1 + a + a - --- - 4 a z + 8 z - ---- + -- + a z - 3 a z -

                a                     4     2
                                     a     a

    3      3                              4      4
 2 z    8 z         3      3  3      4   z    2 z       2  4    4  4
 ---- + ---- + 8 a z  - 2 a  z  - 6 z  + -- - ---- - 2 a  z  + a  z  + 
   3     a                                4     2
  a                                      a     a

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

- + 2 q + ----- + ----- + ----- + ---- + --- + 2 q t + q t + 2 q t + q 9 4 5 3 5 2 3 q t

         q  t    q  t    q  t    q  t

  5  3    9  4
q t + q t