Variations on an oriental folksong: The algebraist's introduction to Thom spectra

What Thom's construction could mean, algebraically.

Adams tower on bounded below spectra

Finally had an argument that I'm happy with

Localisation and telescope: Inverting endomorphisms in (homotopy) algebra

A short cautionary tale. Stabilisation, localisation or group completion.

(Central) group extensions from the homotopy perspective

A classical lemma used to construct k-invariants, and its relation to group extensions