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Related papers: $\beta$-diversity and Graph Sheaf Laplacians

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Tsallis has proposed a generalisation of the standard entropy, which has since been applied to a variety of physical systems. In the canonical ensemble approach that is mostly used, average energy is given by an unnromalised, or normalised,…

Statistical Mechanics · Physics 2009-10-31 S. Kalyana Rama

Statistical inference on biodiversity has a rich history going back to RA Fisher. An influential ecological theory suggests the existence of a fundamental biodiversity number, denoted $\alpha$, which coincides with the precision parameter…

Methodology · Statistics 2025-02-04 Tommaso Rigon , Ching-Lung Hsu , David B. Dunson

We introduce a notion of a sheaf of vector spaces on a graph, and develop the foundations of homology theories for such sheaves. One sheaf invariant, its "maximum excess," has a number of remarkable properties. It has a simple definition,…

Combinatorics · Mathematics 2011-06-20 Joel Friedman

Graph Laplacians on finite compact metric graphs are considered under the assumption that the matching conditions at the graph vertices are of either $\delta$ or $\delta'$ type. In either case, an infinite series of trace formulae which…

Mathematical Physics · Physics 2014-04-01 Yulia Ershova , Alexander V. Kiselev

In ecology we may find scenarios where the same phenomenon (species occurrence, species abundance, etc.) is observed using two different types of samplers. For instance, species data can be collected from scientific sampling with a…

One of the first successes of neutral ecology was to predict realistically-broad distributions of rare and abundant species. However, it has remained an outstanding theoretical challenge to describe how this distribution of abundances…

Populations and Evolution · Quantitative Biology 2018-07-18 James P. O'Dwyer , Stephen J. Cornell

This paper serves a twofold purpose. First, a unified perspective on diversity indices is introduced based on an entropic basis. It is shown that the class of all linear combinations of the entropic basis, referred to as the class of linear…

Statistics Theory · Mathematics 2020-01-22 Zhiyi Zhang , Michael Grabchak

Ecology studies biodiversity in its variety and complexity. It describes how species distribute and perform in response to environmental changes. Ecological processes and structures are highly complex and adaptive. In order to quantify…

Populations and Evolution · Quantitative Biology 2013-10-09 Cang Hui

Many methods have been developed for finding the commonalities between different organisms to study their phylogeny. The structure of metabolic networks also reveal valuable insights into metabolic capacity of species as well as into the…

Molecular Networks · Quantitative Biology 2016-04-08 Krishanu Deyasi , Anirban Banerjee , Bony Deb

The behavior of ecological systems mainly relies on the interactions between the species it involves. We consider the problem of inferring the species interaction network from abundance data. To be relevant, any network inference…

Applications · Statistics 2019-10-29 Raphaëlle Momal , Stéphane Robin , Christophe Ambroise

We study how the properties of a Lagrangian density for a single real scalar field in flat spacetime change with inclusion of an overall factor depending only on the field. The focus of the paper is to obtain analytical results. So, we show…

High Energy Physics - Theory · Physics 2017-11-20 L. Losano , M. A. Marques , R. Menezes

Spectral techniques are popular and robust approaches to data analysis. A prominent example is the use of eigenvectors of a Laplacian, constructed from data affinities, to identify natural data groupings or clusters, or to produce a…

Dynamical Systems · Mathematics 2024-08-09 Gary Froyland

In this paper we describe the emergence of scale-free degree distributions from statistical mechanics principles. We define an energy associated to a degree sequence as the logarithm of the number of indistinguishable simple networks it is…

Statistical Mechanics · Physics 2007-05-23 Ginestra Bianconi

Many inference tasks on knowledge graphs, including relation prediction, operate on knowledge graph embeddings -- vector representations of the vertices (entities) and edges (relations) that preserve task-relevant structure encoded within…

Artificial Intelligence · Computer Science 2026-01-19 John Cobb , Thomas Gebhart

We present an analytically tractable variant of the voter model that provides a quantitatively accurate description of beta-diversity (two-point correlation function) in two tropical forests. The model exhibits novel scaling behavior that…

Populations and Evolution · Quantitative Biology 2007-05-23 Tommaso Zillio , Igor Volkov , Jayanth R. Banavar , Stephen P. Hubbell , Amos Maritan

We analyze the nonlinear relaxation of a complex ecosystem composed of many interacting species. The ecological system is described by generalized Lotka-Volterra equations with a multiplicative noise. The transient dynamics is studied in…

Statistical Mechanics · Physics 2016-11-23 M. A. Cirone , F. de Pasquale , B. Spagnolo

Much of our understanding of ecological and evolutionary mechanisms derives from analysis of low-dimensional models: with few interacting species, or few axes defining "fitness". It is not always clear to what extent the intuition derived…

Populations and Evolution · Quantitative Biology 2018-02-14 Mikhail Tikhonov , Remi Monasson

The analysis of benthic assemblages is a valuable tool to describe the ecological status of transitional water ecosystems, but species are extremely sensitive and respond to both microhabitat and seasonal differences. The identification of…

Populations and Evolution · Quantitative Biology 2017-05-25 Giovanna Jona Lasinio , Alessio Pollice , Eric Marcon , Elisa Anna Fano

The theory of {\Gamma}-species is developed to allow species-theoretic study of quotient structures in a categorically rigorous fashion. This new approach is then applied to two graph-enumeration problems which were previously unsolved in…

Combinatorics · Mathematics 2012-04-09 Andrew Gainer

Quantitative methods for studying biodiversity have been traditionally rooted in the classical theory of finite frequency tables analysis. However, with the help of modern experimental tools, like high throughput sequencing, we now begin to…

Methodology · Statistics 2015-12-22 Maciej Pietrzak , Grzegorz A. Rempała , Michał Seweryn , Jacek Wesołowski