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JOURNALS // Chebyshevskii Sbornik // Archive

Chebyshevskii Sb., 2024 Volume 25, Issue 2, Pages 243–250 (Mi cheb1429)

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Sufficient conditions for the existence of the solution of an infinite-difference equation with variable coefficients

S. E. Nohrin, V. T. Shevaldin

Krasovskii Institute of Mathematics and Mechanics (Ural Branch) of the RAS (Yekaterinburg)

Abstract: The paper discusses a difference equation of the form $\sum_{l=0}^{r}a_{k,l}Z_{k+l}=y_{k}\ (k\in \mathbb{Z})$, where $r\in \mathbb{N},\ y=\{y_k\}_{k\in \mathbb{Z}}$ is a given numerical sequence from the space ${{l}_{p}}\ (1\le p<\infty)$, provided that the matrix $A=(a_{k,l})$, $a_{k,l}\in \mathbb{R}$, satisfies some condition close to the presence of a dominant diagonal. With the help of the fixed point theorem, sufficient conditions are written for the coefficients $a_{k,l}$, at which the equation has a unique solution $Z=\{ Z_{k}\}_{k\in \mathbb{Z}}$, belonging to the space $l_p$. For the norm of this solution, a numerical estimate is given from above.

Keywords: difference equation, sequences, space $l_p$, solution norm.

UDC: 517, 518.85

Received: 13.04.2024
Accepted: 28.06.2024

DOI: 10.22405/2226-8383-2024-25-2-243-250



© Steklov Math. Inst. of RAS, 2024