Exceptional points of two-dimensional random walks at multiples of the cover time
We study exceptional sets of the local time of the continuous-time simple random walk in scaled-up (by N ) versions D N ⊆ Z 2 of bounded open domains D ⊆ R 2 . Upon exit from D N , the walk lands on a “boundary vertex” and then reenters D N through a random boundary edge in the next step. In the...
Gespeichert in:
Veröffentlicht in: | Probability theory and related fields 2022-06, Vol.183 (1-2), p.1-55 |
---|---|
Hauptverfasser: | , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | We study exceptional sets of the local time of the continuous-time simple random walk in scaled-up (by
N
) versions
D
N
⊆
Z
2
of bounded open domains
D
⊆
R
2
. Upon exit from
D
N
, the walk lands on a “boundary vertex” and then reenters
D
N
through a random boundary edge in the next step. In the parametrization by the local time at the “boundary vertex” we prove that, at times corresponding to a
θ
-multiple of the cover time of
D
N
, the sets of suitably defined
λ
-thick (i.e., heavily visited) and
λ
-thin (i.e., lightly visited) points are, as
N
→
∞
, distributed according to the Liouville Quantum Gravity
Z
λ
D
with parameter
λ
-times the critical value. For
θ
<
1
, also the set of avoided vertices (a.k.a. late points) and the set where the local time is of order unity are distributed according to
Z
θ
D
. The local structure of the exceptional sets is described as well, and is that of a pinned Discrete Gaussian Free Field for the thick and thin points and that of random-interlacement occupation-time field for the avoided points. The results demonstrate universality of the Gaussian Free Field for these extremal problems. |
---|---|
ISSN: | 0178-8051 1432-2064 |
DOI: | 10.1007/s00440-022-01113-4 |