L9a4

L9a3

L9a5

(Knotscape image)	See the full Thistlethwaite Link Table (up to 11 crossings). Visit L9a4 at Knotilus!
	L9a4 is $9^2_{18}$ in the Rolfsen table of links.

Link Presentations

[edit Notes on L9a4's Link Presentations]

Planar diagram presentation	X6172 X10,4,11,3 X12,8,13,7 X16,10,17,9 X18,14,5,13 X14,18,15,17 X8,16,9,15 X2536 X4,12,1,11
Gauss code	{1, -8, 2, -9}, {8, -1, 3, -7, 4, -2, 9, -3, 5, -6, 7, -4, 6, -5}

A Braid Representative
A Morse Link Presentation

Polynomial invariants

Multivariable Alexander Polynomial (in $u$, $v$, $w$, ...)	$-\frac{2 (u-1) (v-1) \left(v^2-v+1\right)}{\sqrt{u} v^{3/2}}$ (db)
Jones polynomial	$q^{17/2}-3 q^{15/2}+6 q^{13/2}-7 q^{11/2}+8 q^{9/2}-9 q^{7/2}+6 q^{5/2}-5 q^{3/2}+2 \sqrt{q}-\frac{1}{\sqrt{q}}$ (db)
Signature	3 (db)
HOMFLY-PT polynomial	$z^3 a^{-7} +z a^{-7} + a^{-7} z^{-1} -z^5 a^{-5} -2 z^3 a^{-5} -2 z a^{-5} -2 a^{-5} z^{-1} -z^5 a^{-3} -2 z^3 a^{-3} -z a^{-3} +z^3 a^{-1} +2 z a^{-1} + a^{-1} z^{-1}$ (db)
Kauffman polynomial	$-z^8 a^{-4} -z^8 a^{-6} -2 z^7 a^{-3} -6 z^7 a^{-5} -4 z^7 a^{-7} -2 z^6 a^{-2} -4 z^6 a^{-4} -7 z^6 a^{-6} -5 z^6 a^{-8} -z^5 a^{-1} +z^5 a^{-3} +10 z^5 a^{-5} +5 z^5 a^{-7} -3 z^5 a^{-9} +4 z^4 a^{-2} +11 z^4 a^{-4} +16 z^4 a^{-6} +8 z^4 a^{-8} -z^4 a^{-10} +3 z^3 a^{-1} +4 z^3 a^{-3} -6 z^3 a^{-5} -4 z^3 a^{-7} +3 z^3 a^{-9} -z^2 a^{-2} -8 z^2 a^{-4} -13 z^2 a^{-6} -5 z^2 a^{-8} +z^2 a^{-10} -3 z a^{-1} -2 z a^{-3} +3 z a^{-5} +2 z a^{-7} - a^{-2} +3 a^{-4} +5 a^{-6} +2 a^{-8} + a^{-1} z^{-1} -2 a^{-5} z^{-1} - a^{-7} z^{-1}$ (db)

Khovanov Homology

The coefficients of the monomials $t^rq^j$ are shown, along with their alternating sums $\chi$ (fixed $j$, alternation over $r$).

\   r    \    j   \ -2 -1 0 1 2 3 4 5 6 7 χ 18                   1 -1 16                 2   2 14               4 1   -3 12             3 2     1 10           5 4       -1 8         4 3         1 6       2 5           3 4     3 4             -1 2   1 4               3 0   1                 -1 -2 1                   1

Integral Khovanov Homology (db, data source)

$\dim{\mathcal G}_{2r+i}\operatorname{KH}^r_{\mathbb Z}$ $i=2$ $i=4$ $r=-2$ ${\mathbb Z}$ $r=-1$ ${\mathbb Z}\oplus{\mathbb Z}_2$ ${\mathbb Z}$ $r=0$ ${\mathbb Z}^{4}\oplus{\mathbb Z}_2$ ${\mathbb Z}^{3}$ $r=1$ ${\mathbb Z}^{4}\oplus{\mathbb Z}_2^{2}$ ${\mathbb Z}^{2}$ $r=2$ ${\mathbb Z}^{5}\oplus{\mathbb Z}_2^{4}$ ${\mathbb Z}^{4}$ $r=3$ ${\mathbb Z}^{3}\oplus{\mathbb Z}_2^{5}$ ${\mathbb Z}^{5}$ $r=4$ ${\mathbb Z}^{4}\oplus{\mathbb Z}_2^{3}$ ${\mathbb Z}^{3}$ $r=5$ ${\mathbb Z}^{2}\oplus{\mathbb Z}_2^{4}$ ${\mathbb Z}^{4}$ $r=6$ ${\mathbb Z}\oplus{\mathbb Z}_2^{2}$ ${\mathbb Z}^{2}$ $r=7$ ${\mathbb Z}_2$ ${\mathbb Z}$

Computer Talk

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

Modifying This Page

Read me first: Modifying Knot Pages See/edit the Link Page master template (intermediate). See/edit the Link_Splice_Base (expert). Back to the top.

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