Braid groups

Braid groups are a fundamental concept in algebraic topology and group theory. They arise from the study of braids, which can be visualized as strands of string intertwined in a specific manner. ### Definition The braid group \( B_n \) consists of equivalence classes of braids with \( n \) strands. Each braid can be represented as a series of points in a plane, where strands are allowed to cross over each other but cannot break or end.