ScalingStacks

Theorem 3.1. The $\infty$-category of small idempotent-complete stable $\infty$-categories is a closed symmetric monoidal category with respect to $\widehat{\otimes}$. The unit is the $\infty$-category ${\mathcal{S}}_{\infty}^{\omega}$ of compact spectra and the internal mapping object is given for small idempotent-complete stable $\infty$-categories ${\mathcal{A}}$ and ${\mathcal{B}}$ by $\mathrm{Fun}^{\ex}({\mathcal{A}},{\mathcal{B}})$.