Results 31 to 40 of about 1,300,131 (168)

Evaluating Environmental Predictors of Fish Community Composition in a Semi‐Arid River System Using a Model‐Based Approach

Ecology of Freshwater Fish, Volume 34, Issue 3, July 2025.
ABSTRACT Understanding how the environment shapes species distribution and affects biodiversity patterns is important in ecology and conservation. Environmental stressors like climate change and anthropogenic impacts may lead to a significant decline in aquatic biodiversity.
Mojgan Zare Shahraki, Pejman Fathi, Sami Domisch, Andreas Bruder, Eisa Ebrahimi Dorcheh, Alireza Esmaeili Ofogh, Thomas Mehner   +6 more
wiley   +1 more source

Umbral Theory and the Algebra of Formal Power Series

Axioms
Umbral theory, formulated in its modern version by S. Roman and G. C. Rota, has been reconsidered in more recent times by G. Dattoli and collaborators with the aim of devising a working computational tool in the framework of special function theory ...
Roberto Ricci
doaj   +1 more source

Improved Gevrey‐1 Estimates of Formal Series Expansions of Center Manifolds

Studies in Applied Mathematics, Volume 154, Issue 6, June 2025.
ABSTRACT In this paper, we show that the coefficients ϕn$\phi _n$ of the formal series expansions ∑n=1∞ϕnxn∈xC[[x]]$\sum _{n=1}^\infty \phi _n x^n\in x\mathbb {C}[[x]]$ of center manifolds of planar analytic saddle‐nodes grow like Γ(n+a)$\Gamma (n+a)$ (after rescaling x$x$) as n→∞$n\rightarrow \infty$.
Kristian Uldall Kristiansen
wiley   +1 more source

Gevrey regularity of subelliptic Monge-Ampère equations in the plane

, 2011
25 pagesInternational audienceIn this paper, we establish the Gevrey regularity of solutions for a class of degenerate Monge-Amp\'{e}re equations in the plane, under the assumption that one principle entry of the Hessian is strictly positive and an ...
Xu, Chao-Jiang, Li, Weixi, Chen, Hua
core   +3 more sources

Newton Polygons and Formal Gevrey Classes

Publications of the Research Institute for Mathematical Sciences, 1990
Untersucht wird ein Cauchyproblem \(Pu=f(t,x)\), \(D^ j_ tu|_{t=0}=g_ j\) (0\(\leq j\leq m-1)\) wobei P die Form hat \(P=D_ t^ m+\sum_{0\leq jm\) ist. Hierzu existiert eine eindeutige Lösung \(u\in G^{\infty}\), nämlich als eine formale Potenzreihe. Gezeigt wird: es ist \(u\in G^ s\) mit \(s=1+1/k_ 1\).
openaire   +3 more sources

New Lower Bounds of Spatial Analyticity Radius for the Kawahara Equation

International Journal of Differential Equations, Volume 2025, Issue 1, 2025.
In this paper, an algebraic decay rate for the radius of spatial analyticity of solutions to the Kawahara equation ∂tu+β∂x5u+α∂x3u+u∂xu=00,β≠ is investigated. With given analytic initial data having a fixed radius of analyticity σ0, we derive an algebraic decay rate σ(t) ~ |t|−1/2 for the uniform radius of spatial analyticity of solutions to the ...
Tegegne Getachew, Jaume Giné
wiley   +1 more source

On nonlinear Landau damping and Gevrey regularity [PDF]

, 2023
In this article we study the problem of nonlinear Landau damping for the Vlasov-Poisson equations on the torus. As our main result we show that for perturbations initially of size $\epsilon > 0$ and time intervals $(0, \epsilon−N)$ one obtains nonlinear ...
Zillinger, Christian
core   +1 more source

Asymptotic Lower Bound on the Spatial Analyticity Radius for Solutions of the Periodic Fifth Order KdV–BBM Equation

International Journal of Differential Equations, Volume 2025, Issue 1, 2025.
In this work, consideration is given to the initial value problem associated with the periodic fifth‐order KdV–BBM equation. It is shown that the uniform radius of spatial analyticity σ(t) of solution at time t is bounded from below by ct−2/3 (for some c > 0), given initial data η0 that is analytic on the circle and has a uniform radius of spatial ...
Tegegne Getachew, Giovanni P. Galdi
wiley   +1 more source

Algebraic Lower Bounds on the Spatial Analyticity Radius for Higher Order Nonlinear Schrödinger Equations

Journal of Applied Mathematics, Volume 2025, Issue 1, 2025.
We investigate the initial value problem associated to the higher order nonlinear Schrödinger equation i∂tu+−1j+1∂x2ju=u2ju x,t≠0∈ℝ,ux,0=u0x, where j ≥ 2 is any integer, u is a complex valued function, and the initial data u0 is real analytic on ℝ and has a uniform radius of spatial analyticity σ0 in the space variable.
Tegegne Getachew, Birilew Belayneh, Betre Shiferaw, Huaiqin Wu   +3 more
wiley   +1 more source