The largest common subtree of two random trees

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Angel, Omer, Atamanchuk, Caelan, Brandenberger, Anna, Donderwinkel, Serte, Khanfir, Robin
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914229729099776
author Angel, Omer
Atamanchuk, Caelan
Brandenberger, Anna
Donderwinkel, Serte
Khanfir, Robin
author_facet Angel, Omer
Atamanchuk, Caelan
Brandenberger, Anna
Donderwinkel, Serte
Khanfir, Robin
contents We study the size and structure of the largest common subtree (LCS) between two independent Bienaymé trees conditioned to have size $n$. When the trees are critical with finite $2$nd and $(2+κ)$th moment respectively for some $κ>0$, we prove that the LCS has size of order $\sqrt{n}$, and is approximated by the length of three paths meeting at a central node. Moreover, we show that the largest common subtree between two critical independent Bienaymé trees with size $n$ and finite second moments may be much larger than $\sqrt{n}$, implying that our result is tight. We also pose a number of open questions and suggestions for future research.
format Preprint
id arxiv_https___arxiv_org_abs_2601_00119
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The largest common subtree of two random trees
Angel, Omer
Atamanchuk, Caelan
Brandenberger, Anna
Donderwinkel, Serte
Khanfir, Robin
Probability
Combinatorics
60C05, 60J80, 05C05, 05C60
We study the size and structure of the largest common subtree (LCS) between two independent Bienaymé trees conditioned to have size $n$. When the trees are critical with finite $2$nd and $(2+κ)$th moment respectively for some $κ>0$, we prove that the LCS has size of order $\sqrt{n}$, and is approximated by the length of three paths meeting at a central node. Moreover, we show that the largest common subtree between two critical independent Bienaymé trees with size $n$ and finite second moments may be much larger than $\sqrt{n}$, implying that our result is tight. We also pose a number of open questions and suggestions for future research.
title The largest common subtree of two random trees
topic Probability
Combinatorics
60C05, 60J80, 05C05, 05C60
url https://arxiv.org/abs/2601.00119