Given a branching random walk, let $M_n$ be the minimum position of any member of the $n$th generation. We calculate $\\mathbfEM_n$ to within O(1) and prove exponential tail bounds for $\\mathbfP{|M_n-\\mathbfEM_n|>x}$, under quite general conditions on the branching random walk. In particular, together with work by Bramson [Z. Wahrsch. Verw....
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2009 (v1)Journal articleUploaded on: December 3, 2022
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2007 (v1)Journal article
We show that every oriented path of order n>=4 with two blocks is contained in every n-chromatic digraph.
Uploaded on: December 4, 2022 -
2005 (v1)Report
We show that every oriented path of order $n\geq4$ with two blocks is contained in every $n$-chromatic digraph.
Uploaded on: December 3, 2022 -
July 2, 2008 (v1)Conference paper
Art gallery problems have been extensively studied over the last decade and have found different type of applications. Normally the number of sides of a polygon or the general shape of the polygon is used as a measure of the complexity of the problem. In this paper we explore another measure of complexity, namely, the number of guards required...
Uploaded on: December 4, 2022 -
2013 (v1)Journal article
Let $f(k)$ be the smallest integer such that every $f(k)$-chromatic digraph contains every oriented tree of order $k$. Burr proved $f(k)\leq (k-1)^2$ in general, and he conjectured $f(k)=2k-2$. Burr also proved that every $(8k-7)$-chromatic digraph contains every antidirected tree. We improve both of Burr's bounds. We show that $f(k)\leq...
Uploaded on: February 28, 2023 -
January 2011 (v1)Report
Let f (k) be the smallest integer such that every f (k)-chromatic digraph contains every oriented tree of order k. Burr proved that f (k) ≤ (k − 1)^2 and conjectured f (k) = 2n − 2. In this paper, we give some sufficient conditions for an n-chromatic digraphs to contains some oriented tree. In particular, we show that every acyclic n-chromatic...
Uploaded on: December 3, 2022