Generalised Swan modules and the D(2) problem.
Generalized classes of groups, C-nilpotent spaces and "The Hurewicz theorem".
Gradient otopies of gradient local maps
We introduce various classes of local maps: gradient, gradient-like, proper etc. We prove Parusiński's theorem for otopy classes of gradient local maps.
Group Extensions and Principal Fibrations.
Groupoids and crossed objects in algebraic topology.
Groupoids, stability cokernel sequences and duality
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