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Harrison homology

Recall that when $A$ is an algebra over characteristic 0 field $k$, then

\begin{displaymath}
\HH_*(A)\xrightarrow{\isom}\Om^*_A.
\end{displaymath}

In general there is a decomposition into direct sum
\begin{align*}
\HH_n(A) &= \underbrace{\square\oplus\hdots\oplus \square}_{n\tex...
...ts & \\
\HH_2(A) &= \square \oplus \Om^2_A \\
\HH_1(A) &= \square
\end{align*}
When one considers the first summands in each gradation then what one obtains is called Harrison homology of an algebra $A$. When $M$ is an $A$-bimodule, then $C_n(A, M)=M\ox_A A^{\ox n}$ gives a complex computing Hochschild homology of an algebra $A$ with coefficients in $M$. The complex for Harrison homology we obtain by taking a quotient by the shuffles in $C_n(A, M)$.



Pawel Witkowski 2006-11-07