ScalingStacks

Definition 2.5. A ${\mathcal{A}}$-module is a spectral functor from ${\mathcal{A}}^{\op}$ to the spectral category $\mathcal{S}$ of symmetric spectra. We denote by $\widehat{{\mathcal{A}}}$ the spectral category of ${\mathcal{A}}$-modules.