Results 31 to 40 of about 3,049,692 (344)

Almost Periodic Functions [PDF]

Proceedings of the American Mathematical Society, 1952
One of the aims in the study of almost periodic functions on a group is to generalize the Fejer summation process, whereby the Fourier series may be summed to yield the function. This has been achieved partially by Bochner-von Neumann [1] and Maak [2; 3].J But in [3] Maak says "In general it is not possible to give a summation procedure which may be ...
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Almost periodic solutions with a prescribed spectrum of linear and quasilinear differential equations with almost periodic coefficients and constant time lag (Neutral differential equations) [PDF]

, 2012
summary:The paper is the extension of the author's previous papers and solves more complicated problems. Almost periodic solutions of a certain type of almost periodic linear or quasilinear systems of neutral differential equations are dealt ...
Fischer, Alexandr
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Quasicrystals and Almost Periodicity [PDF]

Communications in Mathematical Physics, 2005
We introduce a topology ${\cal T}$ on the space $U$ of uniformly discrete subsets of the Euclidean space. Assume that $S$ in $U$ admits a unique autocorrelation measure. The diffraction measure of $S$ is purely atomic if and only if $S$ is almost periodic in $(U,{\cal T})$. This result relates idealized quasicrystals to almost periodicity.
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Basic reproduction ratios for almost periodic compartmental models with time delay

, 2020
The theory of basic reproduction ratio R 0 is established for a large class of almost periodic and time-delayed compartmental population models. We first present some dynamical properties for linear almost periodic functional differential systems.
Lizhong Qiang, Bin-Guo Wang, Xiao-Qiang Zhao   +2 more
semanticscholar   +1 more source

Almost periodicity in semiflows [PDF]

Proceedings of the American Mathematical Society, 1995
For a semiflow on a complete metric space we show that if a semiorbit has compact closure and its positive limit set consists of stable points, the orbit is asymptotically almost periodic. Under stronger hypotheses which are more tractable in applications, the same conclusion holds. An application to a scalar delay-differential equation is given.
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Periodic, almost periodic and almost automorphic solutions for SPDEs with monotone coefficients [PDF]

Discrete & Continuous Dynamical Systems - B, 2019
In this paper, we use the variational approach to investigate recurrent properties of solutions for stochastic partial differential equations, which is in contrast to the previous semigroup framework.
Meng-Bi Cheng, Zhenxin Liu
semanticscholar   +1 more source

$C^n$-almost periodic and almost periodic solutions for some nonlinear integral equations

Electronic Journal of Qualitative Theory of Differential Equations, 2012
In this paper, we investigate the existence of $C^n$-almost periodic solution for a class of nonlinear Fredholm integral equations, and the existence of almost periodic solution for a class of nonlinear functional integral equations.
Huisheng Ding, Yuan-Yuan Chen, Gaston N'Guérékata   +2 more
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Infinite-dimensional Lur'e systems with almost periodic forcing [PDF]

, 2020
We consider forced Lur’e systems in which the linear dynamic component is an infinite-dimensional well-posed system. Numerous physically motivated delay- and partial-differential equa-tions are known to belong to this class of infinite ...
Gilmore, Max E., Guiver, C., Logemann, H.   +2 more
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Limit periodic linear difference systems with coefficient matrices from commutative groups

Electronic Journal of Qualitative Theory of Differential Equations, 2014
In this paper, limit periodic and almost periodic homogeneous linear difference systems are studied. The coefficient matrices of the considered systems belong to a given commutative group.
Petr Hasil, Michal Veselý
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Partially irregular almost periodic solutions of ordinary differential systems [PDF]

, 2001
summary:Let $f(t,x)$ be a vector valued function almost periodic in $t$ uniformly for $x$, and let ${\mathrm mod}(f)=L_1\oplus L_2$ be its frequency module.
Demenchuk, Alexandr
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