Results 61 to 70 of about 45,205 (253)
Global phylogenetic and functional structure of rodent assemblages
Ecography, EarlyView.Exploring the global patterns of phylogenetic and functional structure of assemblages is key to describe the distribution of biodiversity on Earth and to predict how communities and ecosystem functioning may be affected by anthropogenic pressures. Rodent communities have been studied in this regard in the past, but previous work largely focused on ...
Yoan Fourcade, Bader H. Alhajeri
wiley +1 more source
Jaccard dissimilarity in stochastic community models based on the species‐independence assumption
Ecography, EarlyView.A fundamental problem in ecology is understanding the changes in species composition among sites (i.e. beta‐diversity). It is unclear how spatial heterogeneity in species occupancy across sites shapes patterns of beta‐diversity. To address this question, we develop probabilistic models that consider two spatial or temporal sites, where presence ...
Ryosuke Iritani +5 more
wiley +1 more source
Multivariable Wilson polynomials and degenerate Hecke algebras [PDF]
Selecta Mathematica, 2007 We study a rational version of the double affine Hecke algebra associated to the nonreduced affine root system of type $(C^\vee_n,C_n)$. A certain representation in terms of difference-reflection operators naturally leads to the definition of nonsymmetric versions of the multivariable Wilson polynomials.
Wolter Groenevelt
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The Universal Askey-Wilson Algebra
Symmetry, Integrability and Geometry: Methods and Applications, 2011 In 1992 A. Zhedanov introduced the Askey-Wilson algebra AW=AW(3) and used it to describe the Askey-Wilson polynomials. In this paper we introduce a central extension Δ of AW, obtained from AW by reinterpreting certain parameters as central elements in ...
Paul Terwilliger
doaj +1 more source
Nevanlinna Theory of the Wilson Divided-difference Operator
, 2017 Sitting at the top level of the Askey-scheme, Wilson polynomials are regarded as the most general hypergeometric orthogonal polynomials. Instead of a differential equation, they satisfy a second order Sturm-Liouville type difference equation in terms of ...
Cheng, Kam Hang, Chiang, Yik-Man
core +1 more source
Bijections behind the Ramanujan Polynomials [PDF]
, 2001 The Ramanujan polynomials were introduced by Ramanujan in his study of power series inversions. In an approach to the Cayley formula on the number of trees, Shor discovers a refined recurrence relation in terms of the number of improper edges, without ...
Chen, William Y. C., Guo, Victor J. W.
core +3 more sources
A Polynomial Blossom for the Askey–Wilson Operator [PDF]
Constructive Approximation, 2018 We introduce a blossoming procedure for polynomials related to the Askey–Wilson operator. This new blossom is symmetric, multiaffine, and reduces to the complex representation of the polynomial on a certain diagonal. This Askey–Wilson blossom can be used to find the Askey–Wilson derivative of a polynomial of any order. We also introduce a corresponding
Simeonov, Plamen, Goldman, Ron
openaire +2 more sources
Ecography, EarlyView.Phytoplankton communities affect carbon dynamics worldwide, strongly influencing the quality and quantity of organic carbon in coastal ecosystems. Yet, we still know little about the impacts of changing phytoplankton community composition on the potential carbon pathways in estuaries and coasts.
Catharina Uth +4 more
wiley +1 more source
Double Affine Hecke Algebras of Rank 1 and the Z_3-Symmetric Askey-Wilson Relations
Symmetry, Integrability and Geometry: Methods and Applications, 2010 We consider the double affine Hecke algebra H=H(k_0,k_1,k_0^v,k_1^v;q) associated with the root system (C_1^v,C_1). We display three elements x, y, z in H that satisfy essentially the Z_3-symmetric Askey-Wilson relations.
Paul Terwilliger, Tatsuro Ito
doaj +1 more source
Factorization of colored knot polynomials at roots of unity
Physics Letters B, 2015 HOMFLY polynomials are the Wilson-loop averages in Chern–Simons theory and depend on four variables: the closed line (knot) in 3d space–time, representation R of the gauge group SU(N) and exponentiated coupling constant q.
Ya. Kononov, A. Morozov
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