9 28

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9 27.gif

9_27

9 29.gif

9_29

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9 28 Quick Notes


9 28 Further Notes and Views

Knot presentations

Planar diagram presentation X1425 X3849 X11,15,12,14 X5,13,6,12 X13,7,14,6 X15,18,16,1 X9,16,10,17 X17,10,18,11 X7283
Gauss code -1, 9, -2, 1, -4, 5, -9, 2, -7, 8, -3, 4, -5, 3, -6, 7, -8, 6
Dowker-Thistlethwaite code 4 8 12 2 16 14 6 18 10
Conway Notation [21,21,2+]

Three dimensional invariants

Symmetry type Reversible
Unknotting number 1
3-genus 3
Bridge index 3
Super bridge index
Nakanishi index 1
Maximal Thurston-Bennequin number [-9][-2]
Hyperbolic Volume 11.5632
A-Polynomial See Data:9 28/A-polynomial

[edit Notes for 9 28's three dimensional invariants]

Four dimensional invariants

Smooth 4 genus
Topological 4 genus
Concordance genus
Rasmussen s-Invariant -2

[edit Notes for 9 28's four dimensional invariants]

Polynomial invariants

Alexander polynomial
Conway polynomial
2nd Alexander ideal (db, data sources)
Determinant and Signature { 51, -2 }
Jones polynomial
HOMFLY-PT polynomial (db, data sources)
Kauffman polynomial (db, data sources)
The A2 invariant
The G2 invariant

Vassiliev invariants

V2 and V3: (1, 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

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 9 28. Nonzero entries off the critical diagonals (if any exist) are highlighted in red.   
\ r
  \  
j \
-6-5-4-3-2-10123χ
5         1-1
3        2 2
1       31 -2
-1      52  3
-3     44   0
-5    54    1
-7   34     1
-9  25      -3
-11 13       2
-13 2        -2
-151         1
Integral Khovanov Homology

(db, data source)

  

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[9, 28]]
Out[2]=  
9
In[3]:=
PD[Knot[9, 28]]
Out[3]=  
PD[X[1, 4, 2, 5], X[3, 8, 4, 9], X[11, 15, 12, 14], X[5, 13, 6, 12], 
 X[13, 7, 14, 6], X[15, 18, 16, 1], X[9, 16, 10, 17], 

X[17, 10, 18, 11], X[7, 2, 8, 3]]
In[4]:=
GaussCode[Knot[9, 28]]
Out[4]=  
GaussCode[-1, 9, -2, 1, -4, 5, -9, 2, -7, 8, -3, 4, -5, 3, -6, 7, -8, 6]
In[5]:=
BR[Knot[9, 28]]
Out[5]=  
BR[4, {-1, -1, 2, -1, -3, 2, 2, -3, -3}]
In[6]:=
alex = Alexander[Knot[9, 28]][t]
Out[6]=  
       -3   5    12             2    3

-15 + t - -- + -- + 12 t - 5 t + t

            2   t
t
In[7]:=
Conway[Knot[9, 28]][z]
Out[7]=  
     2    4    6
1 + z  + z  + z
In[8]:=
Select[AllKnots[], (alex === Alexander[#][t])&]
Out[8]=  
{Knot[9, 28], Knot[9, 29], Knot[10, 163], Knot[11, NonAlternating, 87]}
In[9]:=
{KnotDet[Knot[9, 28]], KnotSignature[Knot[9, 28]]}
Out[9]=  
{51, -2}
In[10]:=
J=Jones[Knot[9, 28]][q]
Out[10]=  
      -7   3    5    8    9    8    8          2

-5 + q - -- + -- - -- + -- - -- + - + 3 q - q

           6    5    4    3    2   q
q q q q q
In[11]:=
Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]
Out[11]=  
{Knot[9, 28]}
In[12]:=
A2Invariant[Knot[9, 28]][q]
Out[12]=  
 -22    -18    -16    3     -12   4    3     2    4    6

q - q + q - --- - q + -- + -- - q + q - q

                     14           6    2
q q q
In[13]:=
Kauffman[Knot[9, 28]][a, z]
Out[13]=  
        2      4    6   z              3        5        7        2

-1 - 5 a - 4 a - a + - + 3 a z + 6 a z + 6 a z + 2 a z + 5 z +

                       a

                                            3
     2  2       4  2      6  2    8  2   2 z         3      3  3
 14 a  z  + 12 a  z  + 2 a  z  - a  z  - ---- - 4 a z  - 7 a  z  - 
                                          a

    5  3      7  3      4       2  4       4  4      6  4    8  4
 9 a  z  - 4 a  z  - 7 z  - 19 a  z  - 17 a  z  - 4 a  z  + a  z  + 

  5
 z         5      3  5      5  5      7  5      6      2  6
 -- - 3 a z  - 5 a  z  + 2 a  z  + 3 a  z  + 3 z  + 7 a  z  + 
 a

    4  6      6  6        7      3  7      5  7    2  8    4  8
8 a z + 4 a z + 3 a z + 6 a z + 3 a z + a z + a z
In[14]:=
{Vassiliev[2][Knot[9, 28]], Vassiliev[3][Knot[9, 28]]}
Out[14]=  
{0, 0}
In[15]:=
Kh[Knot[9, 28]][q, t]
Out[15]=  
4    5     1        2        1        3        2       5       3

-- + - + ------ + ------ + ------ + ------ + ----- + ----- + ----- +

3   q    15  6    13  5    11  5    11  4    9  4    9  3    7  3

q q t q t q t q t q t q t q t

   4       5      4      4     2 t              2      3  2    5  3
 ----- + ----- + ---- + ---- + --- + 3 q t + q t  + 2 q  t  + q  t
  7  2    5  2    5      3      q
q t q t q t q t