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Approximate solutions for integrodifferential equations of the neutral type

B. G. Pachpatte (2010)

Commentationes Mathematicae Universitatis Carolinae

The main objective of the present paper is to study the approximate solutions for integrodifferential equations of the neutral type with given initial condition. A variant of a certain fundamental integral inequality with explicit estimate is used to establish the results. The discrete analogues of the main results are also given.

Approximate solutions of abstract differential equations

Emil Vitásek (2007)

Applications of Mathematics

The methods of arbitrarily high orders of accuracy for the solution of an abstract ordinary differential equation are studied. The right-hand side of the differential equation under investigation contains an unbounded operator which is an infinitesimal generator of a strongly continuous semigroup of operators. Necessary and sufficient conditions are found for a rational function to approximate the given semigroup with high accuracy.

Approximate solutions of matrix differential equations.

Lucas Jódar Sánchez, A. Hervás, D. García Sala (1986)

Stochastica

A method for solving second order matrix differential equations avoiding the increase of the dimension of the problem is presented. Explicit approximate solutions and an error bound of them in terms of data are given.

Approximate weak invariance for semilinear differential inclusions in Banach spaces

Alina Lazu, Victor Postolache (2011)

Open Mathematics

In this paper we give a criterion for a given set K in Banach space to be approximately weakly invariant with respect to the differential inclusion x′(t) ∈ Ax(t) + F(x(t)), where A generates a C 0-semigroup and F is a given multi-function, using the concept of a tangent set to another set. As an application, we establish the relation between approximate solutions to the considered differential inclusion and solutions to the relaxed one, i.e., x′(t) ∈ Ax(t) + c o ¯ F(x(t)), without any Lipschitz conditions...

Approximating the Stability Region for a Differential Equation with a Distributed Delay

S. A. Campbell, R. Jessop (2009)

Mathematical Modelling of Natural Phenomena

We discuss how distributed delays arise in biological models and review the literature on such models. We indicate why it is important to keep the distributions in a model as general as possible. We then demonstrate, through the analysis of a particular example, what kind of information can be gained with only minimal information about the exact distribution of delays. In particular we show that a distribution independent stability region may be obtained in a similar way that delay independent...

Approximation methods for solving the Cauchy problem

Cristinel Mortici (2005)

Czechoslovak Mathematical Journal

In this paper we give some new results concerning solvability of the 1-dimensional differential equation y ' = f ( x , y ) with initial conditions. We study the basic theorem due to Picard. First we prove that the existence and uniqueness result remains true if f is a Lipschitz function with respect to the first argument. In the second part we give a contractive method for the proof of Picard theorem. These considerations allow us to develop two new methods for finding an approximation sequence for the solution....

Approximation of limit cycle of differential systems with variable coefficients

Masakazu Onitsuka (2023)

Archivum Mathematicum

The behavior of the approximate solutions of two-dimensional nonlinear differential systems with variable coefficients is considered. Using a property of the approximate solution, so called conditional Ulam stability of a generalized logistic equation, the behavior of the approximate solution of the system is investigated. The obtained result explicitly presents the error between the limit cycle and its approximation. Some examples are presented with numerical simulations.

Approximation of periodic solutions of a system of periodic linear nonhomogeneous differential equations

Alexander Fischer (2004)

Applications of Mathematics

The present paper does not introduce a new approximation but it modifies a certain known method. This method for obtaining a periodic approximation of a periodic solution of a linear nonhomogeneous differential equation with periodic coefficients and periodic right-hand side is used in technical practice. However, the conditions ensuring the existence of a periodic solution may be violated and therefore the purpose of this paper is to modify the method in order that these conditions remain valid....

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