91 research outputs found
Recurrence and transience for the frog model on trees
The frog model is a growing system of random walks where a particle is added
whenever a new site is visited. A longstanding open question is how often the
root is visited on the infinite -ary tree. We prove the model undergoes a
phase transition, finding it recurrent for and transient for .
Simulations suggest strong recurrence for , weak recurrence for , and
transience for . Additionally, we prove a 0-1 law for all -ary
trees, and we exhibit a graph on which a 0-1 law does not hold.
To prove recurrence when , we construct a recursive distributional
equation for the number of visits to the root in a smaller process and show the
unique solution must be infinity a.s. The proof of transience when relies
on computer calculations for the transition probabilities of a large Markov
chain. We also include the proof for , which uses similar techniques
but does not require computer assistance.Comment: 24 pages, 8 figures to appear in Annals of Probabilit
Choices, intervals and equidistribution
We give a sufficient condition for a random sequence in [0,1] generated by a
-process to be equidistributed. The condition is met by the canonical
example -- the -2 process -- where the th term is whichever of two
uniformly placed points falls in the larger gap formed by the previous
points. This solves an open problem from Itai Benjamini, Pascal Maillard and
Elliot Paquette. We also deduce equidistribution for more general
-processes. This includes an interpolation of the -2 and -2
processes that is biased towards -2.Comment: 18 pages, main theorem more general than previous versio
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