A map of locales $f : X \rightarrow Y$ is closed if it satisfies the [reciprocity relation][1] $f_*(f^*(X) \vee Y) \cong X \vee f_* (Y)$. How can we express a that a map of schemes $f : X \rightarrow Y$ is closed in terms of the direct image $f^*$ and inverse image $f_*$? Is this equivalent to the same reciprocity relation? Is there some tweaking of the setting for locales which gives rise to a similar reciprocity condition for schemes? Note: here $f_*$ and $f^*$ are the direct image and inverse image functors between categories of quasicoherent sheaves on $X$ and $Y$. Any insights are appreciated. [1]: https://ncatlab.org/nlab/show/closed+morphism#between_locales