9 27

From Knot Atlas
Revision as of 20:51, 27 August 2005 by ScottTestRobot (talk | contribs)
Jump to navigationJump to search


9 26.gif

9_26

9 28.gif

9_28

9 27.gif Visit 9 27's page at the Knot Server (KnotPlot driven, includes 3D interactive images!)

Visit 9 27's page at Knotilus!

Visit 9 27's page at the original Knot Atlas!

9 27 Quick Notes


9 27 Further Notes and Views

Knot presentations

Planar diagram presentation X1425 X3,10,4,11 X11,1,12,18 X5,13,6,12 X13,17,14,16 X7,14,8,15 X15,6,16,7 X17,9,18,8 X9,2,10,3
Gauss code -1, 9, -2, 1, -4, 7, -6, 8, -9, 2, -3, 4, -5, 6, -7, 5, -8, 3
Dowker-Thistlethwaite code 4 10 12 14 2 18 16 6 8
Conway Notation [212112]

Three dimensional invariants

Symmetry type Reversible
Unknotting number 1
3-genus 3
Bridge index 2
Super bridge index [math]\displaystyle{ \{4,6\} }[/math]
Nakanishi index 1
Maximal Thurston-Bennequin number [-6][-5]
Hyperbolic Volume 11.
A-Polynomial See Data:9 27/A-polynomial

[edit Notes for 9 27's three dimensional invariants]

Four dimensional invariants

Smooth 4 genus [math]\displaystyle{ 0 }[/math]
Topological 4 genus [math]\displaystyle{ 0 }[/math]
Concordance genus [math]\displaystyle{ 0 }[/math]
Rasmussen s-Invariant 0

[edit Notes for 9 27's four dimensional invariants]

Polynomial invariants

Alexander polynomial [math]\displaystyle{ -t^3+5 t^2-11 t+15-11 t^{-1} +5 t^{-2} - t^{-3} }[/math]
Conway polynomial [math]\displaystyle{ -z^6-z^4+1 }[/math]
2nd Alexander ideal (db, data sources) [math]\displaystyle{ \{1\} }[/math]
Determinant and Signature { 49, 0 }
Jones polynomial [math]\displaystyle{ q^4-3 q^3+5 q^2-7 q+9-8 q^{-1} +7 q^{-2} -5 q^{-3} +3 q^{-4} - q^{-5} }[/math]
HOMFLY-PT polynomial (db, data sources) [math]\displaystyle{ -z^6+2 a^2 z^4+z^4 a^{-2} -4 z^4-a^4 z^2+5 a^2 z^2+2 z^2 a^{-2} -6 z^2-a^4+3 a^2+ a^{-2} -2 }[/math]
Kauffman polynomial (db, data sources) [math]\displaystyle{ a^2 z^8+z^8+3 a^3 z^7+6 a z^7+3 z^7 a^{-1} +3 a^4 z^6+6 a^2 z^6+4 z^6 a^{-2} +7 z^6+a^5 z^5-4 a^3 z^5-8 a z^5+3 z^5 a^{-3} -7 a^4 z^4-17 a^2 z^4-5 z^4 a^{-2} +z^4 a^{-4} -16 z^4-2 a^5 z^3-2 a^3 z^3-4 z^3 a^{-1} -4 z^3 a^{-3} +4 a^4 z^2+12 a^2 z^2+3 z^2 a^{-2} -z^2 a^{-4} +12 z^2+a^5 z+2 a^3 z+2 a z+2 z a^{-1} +z a^{-3} -a^4-3 a^2- a^{-2} -2 }[/math]
The A2 invariant [math]\displaystyle{ -q^{16}+q^{12}-q^{10}+2 q^8+2 q^2-1+2 q^{-2} -2 q^{-4} + q^{-8} - q^{-10} + q^{-12} }[/math]
The G2 invariant [math]\displaystyle{ q^{80}-2 q^{78}+5 q^{76}-8 q^{74}+7 q^{72}-4 q^{70}-6 q^{68}+19 q^{66}-29 q^{64}+33 q^{62}-29 q^{60}+6 q^{58}+22 q^{56}-50 q^{54}+65 q^{52}-56 q^{50}+32 q^{48}+6 q^{46}-42 q^{44}+61 q^{42}-58 q^{40}+33 q^{38}+3 q^{36}-32 q^{34}+41 q^{32}-25 q^{30}-q^{28}+36 q^{26}-53 q^{24}+50 q^{22}-24 q^{20}-20 q^{18}+64 q^{16}-89 q^{14}+88 q^{12}-53 q^{10}+8 q^8+45 q^6-81 q^4+87 q^2-67+26 q^{-2} +16 q^{-4} -47 q^{-6} +48 q^{-8} -25 q^{-10} -5 q^{-12} +31 q^{-14} -41 q^{-16} +24 q^{-18} + q^{-20} -35 q^{-22} +58 q^{-24} -59 q^{-26} +43 q^{-28} -9 q^{-30} -22 q^{-32} +45 q^{-34} -51 q^{-36} +45 q^{-38} -28 q^{-40} +7 q^{-42} +11 q^{-44} -23 q^{-46} +24 q^{-48} -18 q^{-50} +13 q^{-52} -4 q^{-54} -2 q^{-56} +4 q^{-58} -6 q^{-60} +4 q^{-62} -2 q^{-64} + q^{-66} }[/math]

Vassiliev invariants

V2 and V3: (0, -1)
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{ 0 }[/math] [math]\displaystyle{ -8 }[/math] [math]\displaystyle{ 0 }[/math] [math]\displaystyle{ 16 }[/math] [math]\displaystyle{ 8 }[/math] [math]\displaystyle{ 0 }[/math] [math]\displaystyle{ \frac{16}{3} }[/math] [math]\displaystyle{ \frac{64}{3} }[/math] [math]\displaystyle{ -8 }[/math] [math]\displaystyle{ 0 }[/math] [math]\displaystyle{ 32 }[/math] [math]\displaystyle{ 0 }[/math] [math]\displaystyle{ 0 }[/math] [math]\displaystyle{ 56 }[/math] [math]\displaystyle{ 56 }[/math] [math]\displaystyle{ -\frac{152}{3} }[/math] [math]\displaystyle{ \frac{40}{3} }[/math] [math]\displaystyle{ -24 }[/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]0 is the signature of 9 27. Nonzero entries off the critical diagonals (if any exist) are highlighted in red.

\ r
  \  
j \
-5-4-3-2-101234χ
9         11
7        2 -2
5       31 2
3      42  -2
1     53   2
-1    45    1
-3   34     -1
-5  24      2
-7 13       -2
-9 2        2
-111         -1

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[9, 27]]
Out[2]=  
9
In[3]:=
PD[Knot[9, 27]]
Out[3]=  
PD[X[1, 4, 2, 5], X[3, 10, 4, 11], X[11, 1, 12, 18], X[5, 13, 6, 12], 
 X[13, 17, 14, 16], X[7, 14, 8, 15], X[15, 6, 16, 7], X[17, 9, 18, 8], 

X[9, 2, 10, 3]]
In[4]:=
GaussCode[Knot[9, 27]]
Out[4]=  
GaussCode[-1, 9, -2, 1, -4, 7, -6, 8, -9, 2, -3, 4, -5, 6, -7, 5, -8, 3]
In[5]:=
BR[Knot[9, 27]]
Out[5]=  
BR[4, {-1, -1, 2, -1, 2, 2, -3, 2, -3}]
In[6]:=
alex = Alexander[Knot[9, 27]][t]
Out[6]=  
      -3   5    11             2    3

15 - t + -- - -- - 11 t + 5 t - t

           2   t
t
In[7]:=
Conway[Knot[9, 27]][z]
Out[7]=  
     4    6
1 - z  - z
In[8]:=
Select[AllKnots[], (alex === Alexander[#][t])&]
Out[8]=  
{Knot[9, 27], Knot[11, NonAlternating, 4], 
  Knot[11, NonAlternating, 21], Knot[11, NonAlternating, 172]}
In[9]:=
{KnotDet[Knot[9, 27]], KnotSignature[Knot[9, 27]]}
Out[9]=  
{49, 0}
In[10]:=
J=Jones[Knot[9, 27]][q]
Out[10]=  
     -5   3    5    7    8            2      3    4

9 - q + -- - -- + -- - - - 7 q + 5 q - 3 q + q

          4    3    2   q
q q q
In[11]:=
Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]
Out[11]=  
{Knot[9, 27], Knot[11, NonAlternating, 83]}
In[12]:=
A2Invariant[Knot[9, 27]][q]
Out[12]=  
      -16    -12    -10   2    2       2      4    8    10    12

-1 - q + q - q + -- + -- + 2 q - 2 q + q - q + q

                          8    2
q q
In[13]:=
Kauffman[Knot[9, 27]][a, z]
Out[13]=  
                                                                   2
     -2      2    4   z    2 z              3      5         2   z

-2 - a - 3 a - a + -- + --- + 2 a z + 2 a z + a z + 12 z - -- +

                       3    a                                     4
                      a                                          a

    2                           3      3
 3 z        2  2      4  2   4 z    4 z       3  3      5  3       4
 ---- + 12 a  z  + 4 a  z  - ---- - ---- - 2 a  z  - 2 a  z  - 16 z  + 
   2                           3     a
  a                           a

  4      4                           5
 z    5 z        2  4      4  4   3 z         5      3  5    5  5
 -- - ---- - 17 a  z  - 7 a  z  + ---- - 8 a z  - 4 a  z  + a  z  + 
  4     2                           3
 a     a                           a

           6                          7
    6   4 z       2  6      4  6   3 z         7      3  7    8    2  8
 7 z  + ---- + 6 a  z  + 3 a  z  + ---- + 6 a z  + 3 a  z  + z  + a  z
          2                         a
a
In[14]:=
{Vassiliev[2][Knot[9, 27]], Vassiliev[3][Knot[9, 27]]}
Out[14]=  
{0, -1}
In[15]:=
Kh[Knot[9, 27]][q, t]
Out[15]=  
5           1        2       1       3       2       4       3

- + 5 q + ------ + ----- + ----- + ----- + ----- + ----- + ----- + q 11 5 9 4 7 4 7 3 5 3 5 2 3 2

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

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

  9  4
q t