Key points are not available for this paper at this time.
All spaces are assumed to be separable and metrizable. Building on work of van Engelen, Harrington, Michalewski and Ostrovsky, we obtain the following results: Every finite-dimensional analytic space is σ-homogeneous with analytic witnesses, Every finite-dimensional analytic space is σ-homogeneous with pairwise disjoint Δ21 witnesses.
Agostini et al. (Mon,) studied this question.