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Main Author: Belluzi, Maykel
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2401.15799
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author Belluzi, Maykel
author_facet Belluzi, Maykel
contents In this work we consider parabolic equations of the form \[ (u_{\varepsilon})_t +A_{\varepsilon}(t)u_{\varepsilon} = F_{\varepsilon} (t,u_{{\varepsilon} }), \] where $\varepsilon$ is a parameter in $[0,\varepsilon_0)$ and $\{A_{\varepsilon}(t), \ t\in \mathbb{R}\}$ is a family of uniformly sectorial operators. As $\varepsilon \rightarrow 0^{+}$, we assume that the equation converges to \[ u_t +A_{0}(t)u_{} = F_{0} (t,u_{}). \] The time-dependence found on the linear operators $A_{\varepsilon}(t)$ implies that linear process is the central object to obtain solutions via variation of constants formula. Under suitable conditions on the family $A_{\varepsilon}(t)$ and on its convergence to $A_0(t)$ when $\varepsilon \rightarrow 0^{+}$, we obtain a Trotter-Kato type Approximation Theorem for the linear process $U_{\varepsilon}(t,τ)$ associated to $A_{\varepsilon}(t)$, estimating its convergence to the linear process $U_0(t,τ)$ associated to $A_0(t)$. Through the variation of constants formula and assuming that $F_{\varepsilon}$ converges to $F_0$, we analyze how this linear process convergence is transferred to the solution of the semilinear equation. We illustrate the ideas in two examples. First a reaction-diffusion equation in a bounded smooth domain, obtaining convergence of the linear process and solution. As a consequence, we also obtain upper-semicontinuity of the family of pullback attractors associated to each problem. The second example is a nonautonomous strongly damped wave equation and we analyze convergence of solution as we perturb the fractional powers of the associated linear operator.
format Preprint
id arxiv_https___arxiv_org_abs_2401_15799
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Perturbation of parabolic equations with time-dependent linear operators: convergence of linear processes and solutions
Belluzi, Maykel
Analysis of PDEs
35A01, 35B40, 35B41
In this work we consider parabolic equations of the form \[ (u_{\varepsilon})_t +A_{\varepsilon}(t)u_{\varepsilon} = F_{\varepsilon} (t,u_{{\varepsilon} }), \] where $\varepsilon$ is a parameter in $[0,\varepsilon_0)$ and $\{A_{\varepsilon}(t), \ t\in \mathbb{R}\}$ is a family of uniformly sectorial operators. As $\varepsilon \rightarrow 0^{+}$, we assume that the equation converges to \[ u_t +A_{0}(t)u_{} = F_{0} (t,u_{}). \] The time-dependence found on the linear operators $A_{\varepsilon}(t)$ implies that linear process is the central object to obtain solutions via variation of constants formula. Under suitable conditions on the family $A_{\varepsilon}(t)$ and on its convergence to $A_0(t)$ when $\varepsilon \rightarrow 0^{+}$, we obtain a Trotter-Kato type Approximation Theorem for the linear process $U_{\varepsilon}(t,τ)$ associated to $A_{\varepsilon}(t)$, estimating its convergence to the linear process $U_0(t,τ)$ associated to $A_0(t)$. Through the variation of constants formula and assuming that $F_{\varepsilon}$ converges to $F_0$, we analyze how this linear process convergence is transferred to the solution of the semilinear equation. We illustrate the ideas in two examples. First a reaction-diffusion equation in a bounded smooth domain, obtaining convergence of the linear process and solution. As a consequence, we also obtain upper-semicontinuity of the family of pullback attractors associated to each problem. The second example is a nonautonomous strongly damped wave equation and we analyze convergence of solution as we perturb the fractional powers of the associated linear operator.
title Perturbation of parabolic equations with time-dependent linear operators: convergence of linear processes and solutions
topic Analysis of PDEs
35A01, 35B40, 35B41
url https://arxiv.org/abs/2401.15799