
arXiv: 1106.4273
We study maximal orthogonal families of Borel probability measures on $2^ω$ (abbreviated m.o. families) and show that there are generic extensions of the constructible universe $L$ in which each of the following holds: (1) There is a $Δ^1_3$-definable well order of the reals, there is a $Π^1_2$-definable m.o. family, there are no $\mathbfΣ^1_2$-definable m.o. families and $\mathfrak{b}=\mathfrak{c}=ω_3$ (in fact any reasonable value of $\mathfrak{c}$ will do). (2) There is a $Δ^1_3$-definable well order of the reals, there is a $Π^1_2$-definable m.o. family, there are no $\mathbfΣ^1_2$-definable m.o. families, $\mathfrak{b}=ω_1$ and $\mathfrak{c}=ω_2$.
12 pages
101013 Mathematical logic, 101013 Mathematische Logik, QA1-939, FOS: Mathematics, 03E15, 03E17, 03E35, 03E45, Mathematics - Logic, Logic (math.LO), Mathematics
101013 Mathematical logic, 101013 Mathematische Logik, QA1-939, FOS: Mathematics, 03E15, 03E17, 03E35, 03E45, Mathematics - Logic, Logic (math.LO), Mathematics
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