# Names and algorithms for subgraphs with smallest neighbourhoods

I'm curious about some terminology for graphs and the existence of an algorithm. Let $G$ be a graph and $H \leq G$ a subgraph. Is there a name given to $H$ if $|N(H)|$ is minimum over all subgraphs of size $|H|$? Are there algorithms to compute such a set rather than brute force?

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If by $|N(H)|$ you mean neighborhood of $H$, then this is close to the notion of graph expansion.