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Logarithmic Convexity and impulse Approximate Controllability for Degenerate Parabolic Equations with Robin Boundary Conditions

Hind El Baggari, Ilham Ouelddris

TL;DR

This work addresses approximate controllability for a one-dimensional degenerate parabolic equation with Robin boundary conditions at the degeneracy point, subject to an impulsive control in a small region at time \\tau. The authors develop a Carleman commutator-based logarithmic convexity framework to establish a single-time observability inequality for the adjoint system, which they then use to derive null approximate impulse controllability for all final times \\ T, with an explicit cost bound \\mathcal{P}(T,\\epsilon) \\le \\frac{1}{\\epsilon^{\\beta}} e^{\\mathcal{C}(1+1/(T-\\tau))}. The analysis hinges on weighted Sobolev spaces \\ H^1_\\alpha, \\ H^2_\\alpha and a carefully chosen weight \\phi to control boundary terms under Robin conditions. The results provide a constructive, quantitative path to controllability in degenerate parabolic systems with convective boundary effects and impulsive actuation, while highlighting open questions for interior-only control regions.

Abstract

In this work, we investigate the approximate controllability of a class of one-dimensional degenerate parabolic equations with Robin boundary conditions. The degeneracy occurs at one endpoint of the spatial domain, and we apply an impulsive control in a small region at a fixed moment. Our main result establishes an observability inequality for the adjoint system, from which we deduce approximate controllability at final time . The proof relies on a logarithmic convexity argument, developed through a Carleman commutator approach.

Logarithmic Convexity and impulse Approximate Controllability for Degenerate Parabolic Equations with Robin Boundary Conditions

TL;DR

This work addresses approximate controllability for a one-dimensional degenerate parabolic equation with Robin boundary conditions at the degeneracy point, subject to an impulsive control in a small region at time \\tau. The authors develop a Carleman commutator-based logarithmic convexity framework to establish a single-time observability inequality for the adjoint system, which they then use to derive null approximate impulse controllability for all final times \\ T, with an explicit cost bound \\mathcal{P}(T,\\epsilon) \\le \\frac{1}{\\epsilon^{\\beta}} e^{\\mathcal{C}(1+1/(T-\\tau))}. The analysis hinges on weighted Sobolev spaces \\ H^1_\\alpha, \\ H^2_\\alpha and a carefully chosen weight \\phi to control boundary terms under Robin conditions. The results provide a constructive, quantitative path to controllability in degenerate parabolic systems with convective boundary effects and impulsive actuation, while highlighting open questions for interior-only control regions.

Abstract

In this work, we investigate the approximate controllability of a class of one-dimensional degenerate parabolic equations with Robin boundary conditions. The degeneracy occurs at one endpoint of the spatial domain, and we apply an impulsive control in a small region at a fixed moment. Our main result establishes an observability inequality for the adjoint system, from which we deduce approximate controllability at final time . The proof relies on a logarithmic convexity argument, developed through a Carleman commutator approach.
Paper Structure (7 sections, 5 theorems, 115 equations)

This paper contains 7 sections, 5 theorems, 115 equations.

Key Result

Lemma 1.3

Assume that Hypothesis hypo1 holds true. Let us consider $\omega$ a sub-interval of $(0,1)$ that satisfies the geometric condition cond. Then, there exists a positive constant $\mathcal{C}$ and $\rho \in (0,1)$ such that the following observation estimate is satisfied where $u$ is the solution of the following non-impulsive system

Theorems & Definitions (12)

  • Definition 1.1: see Definition 1.2 of qin
  • Definition 1.2
  • Lemma 1.3
  • Proposition 1
  • proof : Proof of Theorem \ref{['thm1']}
  • Lemma 3.1
  • proof
  • Lemma 4.1
  • proof
  • Remark 1
  • ...and 2 more