Antiperiodic Conditions Research Articles

Elastic waves in periodically heterogeneous two-dimensional media: locally periodic and anti-periodic modes

Propagation of anti-plane waves through a discrete square lattice and through a continuous fibrous medium is studied. In the long-wave limit, for periodically heterogeneous structures the solution can be periodic or anti-periodic across the unit cell. It is shown that combining periodicity and anti-periodicity conditions in different directions of the translational symmetry allows one to detect different types of modes that do not arise in the purely periodic case. Such modes may be interpreted as counterparts of non-classical waves appearing in phenomenological theories. Dispersion diagrams of the discrete square lattice are evaluated in a closed analytical from. Dispersion properties of the fibrous medium are determined using Floquet–Bloch theory and Fourier series approximations. Influence of a viscous damping is taken into account.

Existence of anti-periodic solutions for hemivariational inequalities

J. Y. Park and T. G. Ha [Nonlinear Anal., 2008, 68: 747-767; 2009, 71: 3203-3217] investigated the existence of anti-periodic solutions for hemivariational inequalities with a pseudomonotone operator. In this note, we point out that the methods used there are not suitable for the proof of the existence of anti-periodic solutions for hemivariational inequalities and we shall give a straightforward approach to handle these problems. The main tools in our study are the maximal monotone property of the derivative operator with antiperiodic conditions and the surjectivity result for L-pseudomonotone operators.

Boundary Value Problems for Fractional Differential Equations with Integral and Anti-Periodic Conditions in a Banach Space

Boundary Value Problems for Fractional Differential Equations with Integral and Anti-Periodic Conditions in a Banach Space

Properties of size-dependent models having quasiperiodic boundary conditions

Boundary condition effects are explored for size-dependent models in thermal equilibrium. Scalar and fermionic models are used for [Formula: see text] (films), [Formula: see text] (hollow cylinder) and [Formula: see text] (ring). For all models, a minimal length is found, below which no thermally-induced phase transition occurs. Using quasiperiodic boundary condition controlled by a contour parameter [Formula: see text] ([Formula: see text] is a periodic boundary condition and [Formula: see text] is an antiperiodic condition), it results that the minimal length depends directly on the value of [Formula: see text]. It is also argued that this parameter can be associated to an Aharonov–Bohm phase.

On FBDF5 Method for Delay Differential Equations of Fractional Order with Periodic and Anti-Periodic Conditions

In this paper, we study the fractional backward differential formula (FBDF) for the numerical solution of fractional delay differential equations (FDDEs) of the following form: \(\lambda _n {}_0^C D_t^{\alpha _n } y(t - \tau ) + \lambda _{n - 1} {}_0^C D_t^{\alpha _{n - 1} } y(t - \tau ) + \cdots + \lambda _1 {}_0^C D_t^{\alpha _1 } y(t - \tau ) + \lambda _{n + 1} y(t) = f(t), t \in [0,T]\), where \( \lambda _i \in \)\(\mathbb {R}\,(i = 1,\ldots ,n + 1)\,,\,\lambda _{n + 1} \ne 0,\,\, 0 \leqslant \alpha _1 0,\) in Caputo sense. We find the Green’s functions for this equation corresponding to periodic/anti-periodic conditions in term of the Mittag-Leffler type. Our investigation is focused on stability properties of the numerical methods and we determine stability regions for the FDDEs. Finally, some numerical examples are given to show the effectiveness of the numerical method and the results are in excellent agreement with the theoretical analysis

On fractional backward differential formulas for fractional delay differential equations with periodic and anti-periodic conditions

In this paper, fractional backward differential formulas (FBDF) are presented for the numerical solution of fractional delay differential equations (FDDEs) of the form λn0CDtαny(t)+λn−10CDtαn−1y(t)+⋯+λ10CDtα1y(t)+λn+1y(t−τ)=f(t),t∈[0,T], where λi∈R(i=1,⋯,n+1),λn+1≠0,0⩽α1<α2<⋯<αn<1,T>0, in Caputo sense. Our investigation is focused on stability properties of the numerical methods and we determine stability regions for the FDDEs. Also we find the Green's functions for this equation corresponding to periodic/anti-periodic conditions in terms of the functions of Mittag Leffler type. Numerical tests are presented to confirm the strength of the approach under investigation.

Differential inclusions of arbitrary fractional order with anti-periodic conditions in Banach spaces

Differential inclusions of arbitrary fractional order with anti-periodic conditions in Banach spaces

Analysis and control of differential inclusions with anti-periodic conditions

We deal with the optimal control of systems driven by differential inclusions with anti-periodic conditions in Banach spaces. The operators in the differential inclusions, describing the control system, all depend on control variables. By a solution of the control system we mean a ‘trajectory-control’ pair. We first prove that, for fixed control variables, the set of solutions is non-empty for the corresponding differential inclusion with anti-periodic conditions. We then show the functional-topological properties of the set of solutions. Finally, we investigate the existence of solutions to the optimal control problem. These abstract results can be used to study optimal control systems of evolutionary hemi-variational inequalities.

Nonlocal Problems for Differential Inclusions in Hilbert Spaces

An existence theorem for differential inclusions in Hilbert spaces with nonlocal conditions is proved. Periodic, anti-periodic, mean value and multipoint conditions are included in this study. The investigation is based on a combination of the approximation solvability method with Hartman-type inequalities. A feedback control problem associated to a first order partial differential equation completes this discussion.

Lyapunov-type inequalities for a class of higher-order linear differential equations with anti-periodic boundary conditions

Abstract In this paper, we obtain some new Lyapunov-type inequalities for a class of higher-order linear differential equations with anti-periodic boundary value condition, the results of this paper are new and generalize and improve some early results in the literature.

Existence of anti-periodic solutions for a class of first order evolution inclusions

The existence of anti-periodic solutions for a class of first order nonlinear evolution inclusions defined in the framework of an evolution triple of spaces is considered. We study the problems under both convexity and nonconvexity conditions on the multivalued right-hand side. The main tools in our study are the maximal monotone property of the derivative operator with anti-periodic conditions, the surjectivity result for L-pseudomonotone operators and continuous extreme selection results from multivalued analysis. An example of a nonlinear parabolic problem is given to illustrate our results.

Anti-periodic solutions for differential inclusions in Banach spaces and their applications

We deal with anti-periodic problems for differential inclusions with nonmonotone perturbations. The main tools in our study are the maximal monotone property of the derivative operator with anti-periodic conditions and the theory of pseudomonotone perturbations of maximal monotone mappings. We then apply our results to evolution hemivariational inequalities and parabolic equations with nonmonotone discontinuities, which generalize and extend previously known theorems.

Critical exponents from parallel plate geometries subject to periodic and antiperiodic boundary conditions

We introduce a renormalized one-particle irreducible, 1PI, vertex part scalar field theory setting in momentum space to computing the critical exponents ν and η, at least at two-loop order, for a layered parallel plate geometry separated by a distance L, with periodic as well as antiperiodic boundary conditions on the plates. We utilize massive and massless fields in order to extract the exponents in independent ultraviolet and infrared scaling analysis, respectively, which are required in a complete description of the scaling regions for finite size systems. We prove that fixed points and other critical amounts either in the ultraviolet or in the infrared regime dependent on the plates boundary condition are a general feature of normalization conditions. We introduce a new description of typical crossover regimes occurring in finite size systems. Avoiding these crossovers, the three regions of finite size scaling present for each of these boundary conditions are shown to be indistinguishable in the results of the exponents in periodic and antiperiodic conditions, which coincide with those from the (bulk) infinite system.

On a low-frequency asymptotic expansion of a unique weak solutions of a semilinear wave equation with a boundary-like antiperiodic condition

This article is mainly about a low-frequency asymptotic expansion of a unique weak solutions of a semilinear wave equation with a boundary-like antiperiodic condition. Solvability of this problem with weak initial data is also studied by applying the Faedo–Galerkin method and using a maximal continuous solution of a nonlinear Volterra integral equation.

A semilinear wave equation with space–time dependent coefficients and a memory boundarylike antiperiodic condition: A low-frequency asymptotic expansion

This paper studies a low-frequency asymptotic expansion for a unique strong solution to an initial-boundary value problem of a semilinear wave equation. This equation admits space–time dependent coefficients and a memory boundarylike antiperiodic condition. For some small parameters from coefficients of this semilinear wave equation and of boundary conditions, we approximate a unique strong solution to this problem by a polynomial of these parameters, and coefficients of this polynomial are strong solutions of a sequence of well-defined linear initial-boundary value problems.

On the Existence of Anti-periodic Solutions for Implicit Differential Equations

This paper is devoted to anti-periodic solutions for a class of implicit differential equations with nonmonotone perturbations. The main tools in our study will be the maximal monotone property of the derivative operator with anti-periodic conditions and a convergent approximation procedure.

A semilinear wave equation with space-time dependent coefficients and a memory boundarylike antiperiodic condition: Regularity and stability

This paper deals with regularity and stability of solutions to an initial-boundary value problem of a semilinear wave equation. This equation admits space-time dependent coefficients and a memory boundarylike antiperiodic condition. For regularity or existence of a unique strong solution, the Faedo–Galerkin method and the energy method, associated with the maximal solution of a nonlinear Volterra integral equation, are applied. Then, as an application of the regularity result, stability of this unique strong solution is obtained by the energy method.

Regularity of the solution of a nonlinear wave equation

The paper deals with the regularity of the weak solution of anonlinear initial-boundary value problem given by a semi-linearwave equation with space-time dependent coefficients and aboundary-like antiperiodic condition.

Anti-periodic solutions to nonlinear evolution equations

We deal with anti-periodic problems for nonlinear evolution equations with nonmonotone perturbations. The main tools in our study are the maximal monotone property of the derivative operator with anti-periodic conditions and the theory of pseudomonotone perturbations of maximal monotone mappings.

Contraction-Galerkin method for a semi-linear wave equation

In this paper we consider the unique solvability of initial-boundary value problems of semi-linear wave equations with space-time dependent coefficients and special mixed non-homogeneous boundary values which form the so-called boundary-like antiperiodic condition. The procedure in this paper is the combination of the Galerkin method and a contraction.