Characteristic Properties of Differentiable Functions. Differential Equations

Author(s):  
Jürgen Jost
2014 ◽  
Vol 30 (3) ◽  
pp. 309-316
Author(s):  
G. GROZA ◽  
◽  
M. JIANU ◽  
N. POP ◽  
◽  
...  

We study infinitely differentiable functions which are representable into a Newton interpolating series at a suitable interpolation sequence with terms in [0, 1]. Applications of this series to approximate the solution of boundary value problems for linear systems of differential equations are presented.


1995 ◽  
Vol 2 (2) ◽  
pp. 211-224
Author(s):  
T. Werner

Abstract The Cauchy–Nicoletti boundary value problem for a system of ordinary differential equations with pole-type singularities is investigated. The conditions of the existence, uniqueness, and non-uniqueness of a solution in the class of continuously differentiable functions are given. The classical Banach contraction principle is combined with a special transformation of the original problem.


2013 ◽  
Vol 21 (4) ◽  
pp. 261-272
Author(s):  
Keiko Narita ◽  
Noboru Endou ◽  
Yasunari Shidama

Abstract In this article, we describe the differential equations on functions from R into real Banach space. The descriptions are based on the article [20]. As preliminary to the proof of these theorems, we proved some properties of differentiable functions on real normed space. For the proof we referred to descriptions and theorems in the article [21] and the article [32]. And applying the theorems of Riemann integral introduced in the article [22], we proved the ordinary differential equations on real Banach space. We referred to the methods of proof in [30].


2013 ◽  
Vol 5 (1) ◽  
pp. 89-93
Author(s):  
V.I. Myronyk ◽  
V.V. Mykhaylyuk

It is obtained a general solution of first-order linear partial differential equations in the class of separately differentiable functions.


Author(s):  
Zukhra T. Zhukovskaya ◽  
Sergey E. Zhukovskiy

We study the question of the existence of a solution to the Cauchy problem for a differential equation unsolved with respect to the derivative of the unknown function. Differential equations generated by twice continuously differentiable mappings are considered. We give an example showing that the assumption of regularity of the mapping at each point of the domain is not enough for the solvability of the Cauchy problem. The concept of uniform regularity for the considered mappings is introduced. It is shown that the assumption of uniform regularity is sufficient for the local solvability of the Cauchy problem for any initial point in the class of continuously differentiable functions. It is shown that if the mapping defining the differential equation is majorized by mappings of a special form, then the solution of the Cauchy problem under consideration can be extended to a given time interval. The case of the Lipschitz dependence of the mapping defining the equation on the phase variable is considered. For this case, estimates of non-extendable solutions of the Cauchy problem are found. The results are compared with known ones. It is shown that under the assumptions of the proved existence theorem, the uniqueness of a solution may fail to hold. We provide examples llustrating the importance of the assumption of uniform regularity.


2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
V. G. Gupta ◽  
Bhavna Shrama ◽  
Adem Kiliçman

We propose a new definition of a fractional-order Sumudu transform for fractional differentiable functions. In the development of the definition we use fractional analysis based on the modified Riemann-Liouville derivative that we name the fractional Sumudu transform. We also established a relationship between fractional Laplace and Sumudu duality with complex inversion formula for fractional Sumudu transform and apply new definition to solve fractional differential equations.


Fractals ◽  
2011 ◽  
Vol 19 (03) ◽  
pp. 271-290 ◽  
Author(s):  
ABHAY PARVATE ◽  
A. D. GANGAL

Calculus on fractals, or Fα-calculus, developed in a previous paper, is a calculus based fractals F ⊂ R, and involves Fα-integral and Fα-derivative of orders α, 0 < α ≤ 1, where α is the dimension of F. The Fα-integral is suitable for integrating functions with fractal support of dimension α, while the Fα-derivative enables us to differentiate functions like the Cantor staircase. Several results in Fα-calculus are analogous to corresponding results in ordinary calculus, such as the Leibniz rule, fundamental theorems, etc. The functions like the Cantor staircase function occur naturally as solutions of Fα-differential equations. Hence the latter can be used to model processes involving fractal space or time, which in particular include a class of dynamical systems exhibiting sublinear behaviour. In this paper we show that, as operators, the Fα-integral and Fα-derivative are conjugate to the Riemann integral and ordinary derivative respectively. This is accomplished by constructing a map ψ which takes Fα-integrable functions to Riemann integrable functions, such that the corresponding integrals on appropriate intervals have equal values. Under suitable conditions, a restriction of ψ also takes Fα-differentiable functions to ordinarily differentiable functions such that their values at appropriate points are equal. Further, this conjugacy is generalized to one between Sobolev spaces in ordinary calculus and Fα-calculus. This conjugacy is useful, among other things, to find solutions to Fα-differential equations: they can be mapped to ordinary differential equations, and the solutions of the latter can be transformed back to get those of the former. This is illustrated with a few examples.


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