ScalingStacks

Theorem 1.3. (see theoremsย 7.13 and 9.8) Let ๐’œ{\mathcal{A}} be an idempotent-complete small stable โˆž\infty-category. Then, there are natural equivalences of spectra

(1.4) Mapโก(๐’ฐaddโ€‹(๐’ฎโˆžฯ‰),๐’ฐaddโ€‹(๐’œ))\displaystyle\mathrm{Map}({\mathcal{U}}_{\mathrm{add}}({\mathcal{S}}_{\infty}^{\omega}),{\mathcal{U}}_{\mathrm{add}}({\mathcal{A}})) โ‰ƒ\displaystyle\simeq Kโก(๐’œ)\displaystyle K({\mathcal{A}})
(1.5) Mapโก(๐’ฐlocโ€‹(๐’ฎโˆžฯ‰),๐’ฐlocโ€‹(๐’œ))\displaystyle\mathrm{Map}({\mathcal{U}}_{\mathrm{loc}}({\mathcal{S}}_{\infty}^{\omega}),{\mathcal{U}}_{\mathrm{loc}}({\mathcal{A}})) โ‰ƒ\displaystyle\simeq Iโ€‹Kโ€‹(๐’œ),\displaystyle I\mspace{-6.mu}K({\mathcal{A}})\,,

where ๐’ฎโˆžฯ‰{\mathcal{S}}_{\infty}^{\omega} is the small stable โˆž\infty-category of compact spectra. In particular, for all nโˆˆโ„คn\in\mathbb{Z}, we have isomorphisms of abelian groups

(1.6) OPENHomโก(๐’ฐaddโ€‹(๐’ฎโˆžฯ‰)),ฮฃโˆ’nโ€‹๐’ฐaddโ€‹(๐’œ))\displaystyle\Hom({\mathcal{U}}_{\mathrm{add}}({\mathcal{S}}_{\infty}^{\omega})),\Sigma^{-n}{\mathcal{U}}_{\mathrm{add}}({\mathcal{A}})) โ‰ƒKnโ€‹(๐’œ)\displaystyle\simeq K_{n}({\mathcal{A}})
(1.7) OPENHomโก(๐’ฐlocโ€‹(๐’ฎโˆžฯ‰)),ฮฃโˆ’nโ€‹๐’ฐlocโ€‹(๐’œ))\displaystyle\Hom({\mathcal{U}}_{\mathrm{loc}}\,({\mathcal{S}}_{\infty}^{\omega}))\,,\Sigma^{-n}{\mathcal{U}}_{\mathrm{loc}}\,({\mathcal{A}})) โ‰ƒIโ€‹Knโ€‹(๐’œ)\displaystyle\simeq I\mspace{-6.mu}K_{n}({\mathcal{A}})

in the triangulated categories Hoโก(โ„ณadd)\Ho({\mathcal{M}}_{\mathrm{add}}) and Hoโก(โ„ณloc)\Ho({\mathcal{M}}_{\mathrm{loc}}).

Original mathematics by the credited authors. Source collection and HTML conversion remain in progress.

Andrew J. Blumberg, David Gepner, Goncalo Tabuada

Original source: arXiv:1001.2282v4