Jacob’s ladders and the almost exact asymptotic representation of the Hardy-Littlewood integral

In this paper we introduce a nonlinear integral equation such that the system of global solutions to this equation represents the class of a very narrow beam as T → ∞ (an analog of the laser beam) and this sheaf of solutions leads to an almost-exact representation of the Hardy-Littlewood integral (1918). The accuracy of our result is essentially better than the accuracy of related results of Balasubramanian, Heath-Brown, and Ivic.     

A new scheme for solving nonlinear Stratonovich Volterra integral equations via Bernoulli’s approximation

In this paper, an efficient method for solving nonlinear Stratonovich Volterra integral equations is proposed. By using Bernoulli polynomials and their stochastic operational matrix of integration, these equations can be reduced to the system of nonlinear algebraic equations with unknown Bernoulli coefficient which can be solved by numerical methods such as Newton’s method. Also, an error analysis is valid under fairly restrictive conditions. Furthermore, in order to show the accuracy and reliability of the proposed method, the new approach is compared with the block pulse functions method by some examples. The obtained results reveal that the proposed method is more accurate and efficient than the block pulse functions method.     

Study on existence of solutions for some nonlinear functional–integral equations

Using the technique of measures of noncompactness in Banach algebra, we employ abstract fixed point theorems such as Darbo’s theorem to study the existence solution in Banach algebra C[0,a]$C[0,a]$ for some functional–integral equations which include many key integral and functional equations that arise in nonlinear analysis.     

Dispersive deformations of the Hamiltonian structure of Euler’s equations

Euler’s equations for a two-dimensional fluid can be written in the Hamiltonian form, where the Poisson bracket is the Lie–Poisson bracket associated with the Lie algebra of divergence-free vector fields. For the two-dimensional hydrodynamics of ideal fluids, we propose a derivation of the Poisson brackets using a reduction from the bracket associated with the full algebra of vector fields. Taking the results of some recent studies of the deformations of Lie–Poisson brackets of vector fields into account, we investigate the dispersive deformations of the Poisson brackets of Euler’s equation: we show that they are trivial up to the second order.     

A new analytical technique to solve Fredholm’s integral equations

This paper shows that the homotopy analysis method, the well-known method to solve ODEs and PDEs, can be applied as well as to solve linear and nonlinear integral equations with high accuracy. Comparison of the present method with Adomian decomposition method (ADM), which is well-known in solving integral equations, reveals that the ADM is only special case of the present method. Also, some linear and nonlinear examples are presented to show high efficiency and illustrate the steps of the problem resolution.     

A new class of generalized nonlinear functionals of white noise with application to random integral equations ∗

In this paper we introduce some new classes of generalized nonlinear functionals of White noise which have integral representation with kernels either belonging to any L_p (1 ≤ p ≤ ∞)space or any Sobolev space W ^{P, s} for any real s and(1 ≤ p ≤ ∞)Our results extend the class of generelized nonlinear functionals of white noise originally developed by Hida [6, 7, 8] and greatly broaden their scope for application. We conclude the paper with an example involving random integral equations arising from Heat equation excited by White noise on the boundary.     

On nonlinear integral equations and Λ-bounded variation

Summary We discuss the existence or the existence and uniqueness of global and local -bounded variation (BV) solutions as well as continuous BV-solutions of nonlinear Hammerstein and Volterra-Hammerstein integral equations formulated in terms of the Lebesgue integral. Since the space of functions of bounded variation in the sense of Jordan is a proper subspace of functions of -bounded variation and for some class of functions , the space of functions of bounded -variation in the sense of Young is also a proper subspace of the space under consideration, our results extend known results in the literature.     

A new approach to the numerical solution of Volterra integral equations by using Bernstein’s approximation

In this paper, we present a numerical method for solving Volterra integral equations of the second kind (VK2), first kind (VK1) and even singular type of these equations. The proposed method is based on approximating unknown function with Bernstein’s approximation. This method using simple computation with quite acceptable approximate solution. Furthermore we get an estimation of error bound for this method. For showing efficiency of this method we use several examples.     

On solutions of Aczél’s equation and some related equations

Let X be a real linear space and ${M: \mathbb{R}\to\mathbb{R}}$ be continuous and multiplicative. We determine the solutions ${f: X \rightarrow \mathbb{R}}$ of the functional equation $$f(x+M(f(x))y) f(x) f(y) [f(x+M(f(x))y) - f(x)f(y)] = 0$$ that are continuous on rays. In this way we generalize our previous results concerning the continuous solutions of this equation. As a consequence we also obtain some results concerning solutions of a functional equation introduced by J. Aczél.     

New integrable systems with a quartic integral and new generalizations of Kovalevskaya’s and Goriatchev’s cases

In his paper [1], one of us has introduced a method for constructing integrable conservative two-dimensional mechanical systems, on Riemannian 2D spaces, whose second integral is a polynomial in the velocities. This method was applied successfully in [2] to construction of systems admitting a cubic integral and in [3, 4] and [5] to cases of a quartic integral. The present work is devoted to construction of new integrable systems with a quartic integral. The potential is assumed to have the structure

A new FDTD scheme for Maxwell’s equations in Kerr-type nonlinear media

Numerical Algorithms - In this paper, we develop a totally new direct finite difference solver for solving the Maxwell’s equations in Kerr-type nonlinear media. The direct method is free of...     

A reliable treatment of Abel’s second kind singular integral equations

The central idea of this paper is to construct a new mechanism for the solution of Abel’s type singular integral equations that is to say the two-step Laplace decomposition algorithm. The two-step Laplace decomposition algorithm (TSLDA) is an innovative adjustment in the Laplace decomposition algorithm (LDA) and makes the calculation much simpler. In this piece of writing, we merge the Laplace transform and decomposition method and present a novel move toward solving Abel’s singular integral equations.     

Some generalization of Cauchy’s and the quadratic functional equations

We find the solutions ${f,g,h \colon S \to H}$ of each of the functional equations $$\sum\limits_{\lambda \in \Lambda} f(x+\lambda y)=|\Lambda| g(x)+h(y),\quad x,y\in S,$$ where (S,?+) is an abelian semigroup, Λ is a finite subgroup of the automorphism group of S,?(H,?+) is an abelian group.     

Maxwell’s equations,the Euler index,and Morse theory

We show that the singularities of the Fresnel surface for Maxwell’s equation on an anisotrpic material can be accounted from purely topological considerations. The importance of these singularities is that they explain the phenomenon of conical refraction predicted by Hamilton. We show how to desingularise the Fresnel surface, which will allow us to use Morse theory to find lower bounds for the number of critical wave velocities inside the material under consideration. Finally, we propose a program to generalise the results obtained to the general case of hyperbolic differential operators on differentiable bundles.