symmetric monoidal (∞,1)-category of spectra
In higher algebra a higher central extension of some algebraic object should be a higher analog of a central extension, hence a higher extension? by something in the higher analog of the center. What exactly “higher center” should mean is subject to some choices, see for instance center of an ∞-group.
But there is an easily identified sub-class of higher extensions that should definitely count as higher central extensions:
For a group, an ordinary central extension
may equivalently be thought of, via the homotopy theory of ∞-groups, as part of the long homotopy fiber sequence
where is the delooping 2-group of , and where is the cocycle which classifies the central extension.
Equivalently, under further delooping this is the long homotopy fiber sequence of the form
which makes explicitl that is a 2-cocycle.
Phrased this way it is clear that a concept of higher central extension of an ∞-group should subsume at least those long homotopy fiber sequence of the form
where now is the classifying -cocycle.
This concept makese sense not just for ∞-groups in any (∞,1)-topos, but also for instance for (super) L-∞ algebras.
Last revised on October 17, 2024 at 16:52:25. See the history of this page for a list of all contributions to it.