A convergence theory of some methods of integration.
We investigate the convergence behavior of the family of double sine integrals of the form , where (u,v) ∈ ℝ²₊:= ℝ₊ × ℝ₊, ℝ₊:= (0,∞), and f: ℝ²₊ → ℂ is a locally absolutely continuous function satisfying certain generalized monotonicity conditions. We give sufficient conditions for the uniform convergence of the remainder integrals to zero in (u,v) ∈ ℝ²₊ as maxa₁,a₂ → ∞ and , j = 1,2 (called uniform convergence in the regular sense). This implies the uniform convergence of the partial integrals...
Let s: [1,∞) → ℂ be a locally Lebesgue integrable function. We say that s is summable (L,1) if there exists some A ∈ ℂ such that , where . (*) It is clear that if the ordinary limit s(t) → A exists, then also τ(t) → A as t → ∞. We present sufficient conditions, which are also necessary, in order that the converse implication hold true. As corollaries, we obtain so-called Tauberian theorems which are analogous to those known in the case of summability (C,1). For example, if the function s is slowly...
A structure of terms of -faster convergent series is studied in the paper. Necessary and sufficient conditions for the existence of -faster convergent series with different types of their terms are proved. Some consequences are discussed.