\author{David J. Benson}
\address{Institute of Mathematics, University of Aberdeen, Aberdeen AB24 3UE, UK}
\author{Karin Erdmann}
\address{Mathematical Institute, University of Oxford, Oxford OX1 3LB, UK}
\title{Hochschild cohomology of Hecke algebras}
\thanks{This research was partly supported by EPSRC grant EP/D077656/1.}
\begin{document}
\begin{abstract}
We compute the Hochschild cohomology $\HH^*(B)$ of an arbitrary
block $B$ of the Hecke algebra
$\cH=\cH(n,q)$ of the symmetric group
$\fS_n$ at a primitive $\ell$th root of unity $q$, over
a field of characteristic zero.
\end{abstract}