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BurauMatrix ​

The reduced Burau matrix of a braid, an (n−1)×(n−1)(n-1)\times(n-1) matrix over Z[t,t−1]\mathbb{Z}[t,t^{-1}] whose determinant gives the AlexanderPolynomial.

BurauMatrix(braid)the reduced Burau matrix itself
Typed signatures
TypePackageApplies
(expression<Braid> | string) -> list<list<expression>>braidalways

Domain: Braids and knots

Examples

Basic #

A 1×11\times 1 matrix over Z[t,t−1]\mathbb{Z}[t,t^{-1}]

live ↗
InBurauMatrix(Braid(2,[1,1,1]))\mathrm{BurauMatrix}(\mathrm{Braid}(2, \bigl\lbrack1, 1, 1\bigr\rbrack))Out[[−t3]]\bigl\lbrack\bigl\lbrack-t^3\bigr\rbrack\bigr\rbrack

A 2×22\times 2 matrix

live ↗
InBurauMatrix(Braid(3,[1,2]))\mathrm{BurauMatrix}(\mathrm{Braid}(3, \bigl\lbrack1, 2\bigr\rbrack))Out[[0,−t],[t,−t]]\bigl\lbrack\bigl\lbrack0, -t\bigr\rbrack, \bigl\lbrack t, -t\bigr\rbrack\bigr\rbrack
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Examples2

See also: AlexanderPolynomial, Braid