Rapid ultrafilters and summable ideals
  This note answers the following question: Is it consistent that for an arbitrary tall summable ideal I_g there exists an I_g-ultrafilter which is not rapid? We show that assuming Martin's Axiom for \sigma-centered posets such ultrafilters exist for each tall summable ideal I_g. 
Jana Fla\v{s}kov\'a
math.LO