homotopy theory, (∞,1)-category theory, homotopy type theory
flavors: stable, equivariant, rational, p-adic, proper, geometric, cohesive, directed…
models: topological, simplicial, localic, …
see also algebraic topology
Introductions
Definitions
Paths and cylinders
Homotopy groups
Basic facts
Theorems
For , the -stem of the homotopy groups of spheres is the collection of homotopy groups of the form for all , together with the suspension maps between them.
For these groups stabilize (“stable stems”) and yield the stable homotopy groups of spheres.
The “stem”-terminology is due to:
(which otherwise introduced the Freudenthal suspension theorem).
For more see the references at homotopy groups of spheres, such as
Last revised on March 1, 2021 at 18:28:17. See the history of this page for a list of all contributions to it.