Category Archives: Shape theory

Shape injectivity of the earring space (Part II)

This is the sequel to Shape injectivity of the earring space (Part I) We’re on our way to proving the canonical homomorphism from the earring group to the inverse limit of free groups is injective. Part I was mostly dedicated … Continue reading

Posted in Dendrite, Free groups, Fundamental group, Hawaiian earring, Inverse Limit, Peano continuum, Shape theory, Tree, Uncategorized | 3 Comments

The Cech Expansion: nerves of open covers

The Whitehead theorem in homotopy theory basically says that to fully understand the homotopy type of a CW-complex one only needs to know about the homotopy groups (really, the weak homotopy type). It is very easy to produce spaces to … Continue reading

Posted in Shape theory, Simplicial complexes | Tagged , , , , | 4 Comments