THE BURAU REPRESENTATION OF THE BRAID GROUP Bn IS UNFAITHFUL FOR LARGE n
نویسنده
چکیده
Two fundamental theorems of classical knot theory, by J. Alexander, are that every knot is a closed braid, and second, that a certain procedure (see [1,2] for both results) assigns to each knot K a polynomial A(K) in T, which only depends on the topological type of the knot once normalized by a power of T to take a positive value at T = 0. With this normalization, take T to be a transcendental number. Since 1926 [2], it has been known that the function A : Knots —• C is not one-to-one. However, it has not become clear whether the composite
منابع مشابه
Homology of the Braid Group with Coefficients in the Reduced Burau Representation
The reduced Burau representation Vn of the braid group Bn is obtained from the action of Bn on the homology of an infinite cyclic cover of the n-punctured disc. In this paper, we calculate H∗(Bn;Vn) as a module over the Laurent polynomial ring Q[t, t−1].
متن کاملCabling Burau Representation
The Burau representation enables to define many other representations of the braid group Bn by the topological operation of “cabling braids”. We show here that these representations split into copies of the Burau representation itself and of a representation of Bn/(Pn, Pn). In particular, we show that there is no gain in terms of faithfulness by cabling the Burau representation.
متن کاملThe Interplay between Linear Representations of the Braid Group
We considerWada’s representation as a twisted version of the standard action of the braid group, Bn, on the free group with n generators. Constructing a free group, Gnm, of rank nm, we compose Cohen’s map Bn → Bnm and the embedding Bnm → Aut(Gnm) via Wada’s map. We prove that the composition factors of the obtained representation are one copy of Burau representation and m− 1 copies of the stand...
متن کاملHomology of braid groups, the Burau representation, and points on superelliptic curves over finite fields
The (reduced) Burau representation Vn of the braid group Bn is obtained from the action of Bn on the homology of an infinite cyclic cover of the disc with n punctures. In this paper, we calculate H∗(Bn;Vn). Our topological calculation has the following arithmetic interpretation (which also has different algebraic proofs): the expected number of points on a random superelliptic curve of a fixed ...
متن کاملHomology of braid groups, the Burau representation, and Fq-points on superelliptic curves
The (reduced) Burau representation Vn of the braid group Bn is obtained from the action of Bn on the homology of an infinite cyclic cover of the disc with n punctures. In this paper, we calculate H∗(Bn;Vn). As an application, we show that the expected number of Fq-points on a random superelliptic curve is equal to q.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2007