Cardinal characteristics, projective wellorders and large continuum

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Abstract

We extend the work of Fischer et al. (2011) [6] by presenting a method for controlling cardinal characteristics in the presence of a projective wellorder and 20>2. This also answers a question of Harrington (1977) [9] by showing that the existence of a Δ31 wellorder of the reals is consistent with Martinʼs axiom and 20=3.

MSC

03E15
03E20
03E35
03E45

Keywords

Coding
Projective wellorders
Martinʼs axiom
Cardinal characteristics
Large continuum

Cited by (0)

1

The authors would like to thank the Austrian Science Fund FWF for the generous support through grants No. P. 20835-N13 and M1365-N13 (Fischer), P. 22430-N13 (Friedman) and M1244-N13 (Zdomskyy).