BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250811T012353EDT-9405ik5Dh1@132.216.98.100 DTSTAMP:20250811T052353Z DESCRIPTION:The Strange Logic of Galton-Watson Trees\n\nThis talk will focu s on probabilities of first order (FO) and existential monadic second orde r (EMSO) sentences on the Galton-Watson (GW) tree. I shall limit myself to Poisson offspring distributions\, though many of the results can be exten ded to very general distributions. Fix $k in mathbb{N}$. Conditioned on su rvival of the tree\, we show that all FO sentences of quantifier depth k a re determined by a local neighbourhood of the root (of radius $approx 3^{k +2}$). We devise a recursive procedure to compute these probabilities\, co nditioned on the tree's survival. The probabilities are very nice function s of $lambda$ and $p_{lambda}$\, the survival probability. Using Ehrenfeuc ht games and corresponding equivalence classes\, we show that the probabil ity of any FO sentence is analytic in $lambda$.\n \n I shall discuss some of our ongoing work: rogue solutions\, i.e. solutions of equations derived f rom tree automata that do not admit any interpretation\; an example of a s entence that is not expressible almost surely as an EMSO\, etc. I shall en d with speculations and conjectures that hopefully the audience will find fascinating.\n DTSTART:20170126T213000Z DTEND:20170126T223000Z LOCATION:room 1205\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Moumanti Podder\, Courant Institute URL:/mathstat/channels/event/moumanti-podder-courant-i nstitute-265231 END:VEVENT END:VCALENDAR