Displaying similar documents to “Approximate properties of principal solutions of Volterra-type integrodifferential equations with infinite aftereffect”

Asymptotic relationship between solutions of two linear differential systems

Jozef Miklo (1998)

Mathematica Bohemica

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In this paper new generalized notions are defined: Ψ -boundedness and Ψ -asymptotic equivalence, where Ψ is a complex continuous nonsingular n × n matrix. The Ψ -asymptotic equivalence of linear differential systems y ' = A ( t ) y and x ' = A ( t ) x + B ( t ) x is proved when the fundamental matrix of y ' = A ( t ) y is Ψ -bounded.

Essential norms of a potential theoretic boundary integral operator in L 1

Josef Král, Dagmar Medková (1998)

Mathematica Bohemica

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Let G m ( m 2 ) be an open set with a compact boundary B and let σ 0 be a finite measure on B . Consider the space L 1 ( σ ) of all σ -integrable functions on B and, for each f L 1 ( σ ) , denote by f σ the signed measure on B arising by multiplying σ by f in the usual way. 𝒩 σ f denotes the weak normal derivative (w.r. to G ) of the Newtonian (in case m > 2 ) or the logarithmic (in case n = 2 ) potential of f σ , correspondingly. Sharp geometric estimates are obtained for the essential norms of the operator 𝒩 σ - α I (here α ...

Note on functions satisfying the integral Hölder condition

Josef, Jr. Král (1996)

Mathematica Bohemica

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Given a modulus of continuity ω and q [ 1 , [ then H q ω denotes the space of all functions f with the period 1 on that are locally integrable in power q and whose integral modulus of continuity of power q (see(1)) is majorized by a multiple of ω . The moduli of continuity ω are characterized for which H q ω contains “many” functions with infinite “essential” variation on an interval of length 1 .

A method for determining constants in the linear combination of exponentials

Jiří Cerha (1996)

Mathematica Bohemica

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Shifting a numerically given function b 1 exp a 1 t + + b n exp a n t we obtain a fundamental matrix of the linear differential system y ˙ = A y with a constant matrix A . Using the fundamental matrix we calculate A , calculating the eigenvalues of A we obtain a 1 , , a n and using the least square method we determine b 1 , , b n .