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Mare
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When is semigroup algebra local?

Let $G$ be a finite semigroup (or monoid if that helps) and $K$ a field.

Question: When is the semigroup algebra $KG$ local?

Here local means that there is a unique maximal right (or left) ideal.

When $G$ is a group this is true if and only if $G$ is a $p$-group when $K$ has characteristic $p$ (when the characteristic is 0, then $KG$ is only local when $G$ is trivial).

I would hope that there is a similar easy criterion for general semigroups that can be used for example in GAP to filter out all semigroups (among all semigroups with lets say at most 8 elements) with a local semigroup algebra over a given field.

Mare
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