skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Essential differences of potential theories on a tree and on a bi-tree
Award ID(s):
1900268
PAR ID:
10454080
Author(s) / Creator(s):
;
Date Published:
Journal Name:
Comptes Rendus. Mathématique
Volume:
360
Issue:
G9
ISSN:
1778-3569
Page Range / eLocation ID:
1039 to 1048
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. We study the height of a spanning tree $$T$$ of a graph $$G$$ obtained by starting with a single vertex of $$G$$ and repeatedly selecting, uniformly at random, an edge of $$G$$ with exactly one endpoint in $$T$$ and adding this edge to $$T$$. 
    more » « less
  2. Summary Large, majestic trees are iconic symbols of great age among living organisms. Published evidence suggests that trees do not die because of genetically programmed senescence in their meristems, but rather are killed by an external agent or a disturbance event. Long tree lifespans are therefore allowed by specific combinations of life history traits within realized niches that support resistance to, or avoidance of, extrinsic mortality. Another requirement for trees to achieve their maximum longevity is either sustained growth over extended periods of time or at least the capacity to increase their growth rates when conditions allow it. The growth plasticity and modularity of trees can then be viewed as an evolutionary advantage that allows them to survive and reproduce for centuries and millennia. As more and more scientific information is systematically collected on tree ages under various ecological settings, it is becoming clear that tree longevity is a key trait for global syntheses of life history strategies, especially in connection with disturbance regimes and their possible future modifications. In addition, we challenge the long‐held notion that shade‐tolerant, late‐successional species have longer lifespans than early‐successional species by pointing out that tree species with extreme longevity do not fit this paradigm. Identifying extremely old trees is therefore the groundwork not only for protecting and/or restoring entire landscapes, but also to revisit and update classic ecological theories that shape our understanding of environmental change. 
    more » « less
  3. Veeravalli, V. V. (Ed.)
    Abstract—Shared information is a measure of mutual de- pendence among multiple jointly distributed random variables with finite alphabets. For a Markov chain on a tree with a given joint distribution, we give a new proof of an explicit characterization of shared information. The Markov chain on a tree is shown to possess a global Markov property based on graph separation; this property plays a key role in our proofs. When the underlying joint distribution is not known, we exploit the special form of this characterization to provide a multiarmed bandit algorithm for estimating shared information, and analyze its error performance. 
    more » « less