scholarly journals Uniform null controllability for a parabolic equations with discontinuous diffusion coefficient

2021 ◽  
Author(s):  
Jérémi Dardé ◽  
Sylvain Ervedoza ◽  
Roberto Morales
Keyword(s):  
Diffusion Coefficient ◽  
Heat Equation ◽  
Parabolic Equations ◽  
Null Controllability ◽  
Wave Operators ◽  
Conductive Medium ◽  
Geometric Conditions ◽  
Discontinuous Diffusion ◽  
Controllability Result

In this article, we study the null-controllability of a heat equation in a domain composed of two media of different constant conductivities. In particular, we are interested in the behavior of the system when the conductivity of the medium on which the control does not act goes to infinity, corresponding at the limit to a perfectly conductive medium. In that case, and under suitable geometric conditions, we obtain a uniform null-controllability result. Our strategy is based on   the analysis of the controllability of the corresponding wave operators and the transmutation technique, which explains the geometric conditions.

scholarly journals Stackelberg-Nash null controllability of heat equation with general dynamic boundary conditions

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Idriss Boutaayamou ◽  
Lahcen Maniar ◽  
Omar Oukdach
Keyword(s):  
Boundary Conditions ◽  
Heat Equation ◽  
Hierarchical Control ◽  
Null Controllability ◽  
Carleman Estimates ◽  
Dynamic Boundary Conditions ◽  
Dynamic Boundary ◽  
Drift Terms ◽  
Controllability Result ◽  
General Dynamic

<p style='text-indent:20px;'>This paper deals with the hierarchical control of the anisotropic heat equation with dynamic boundary conditions and drift terms. We use the Stackelberg-Nash strategy with one leader and two followers. To each fixed leader, we find a Nash equilibrium corresponding to a bi-objective optimal control problem for the followers. Then, by some new Carleman estimates, we prove a null controllability result.</p>

scholarly journals Regularity and time behavior of the solutions to weak monotone parabolic equations

2021 ◽  
Author(s):  
Maria Michaela Porzio
Keyword(s):  
Heat Equation ◽  
Parabolic Equations ◽  
Parabolic Problems ◽  
Summable Function ◽  
Time Behavior ◽  
Decay Estimates ◽  
Laplacian Equation ◽  
Evolution Problems ◽  
Degenerate Equations ◽  
Uniqueness Results

AbstractIn this paper, we study the behavior in time of the solutions for a class of parabolic problems including the p-Laplacian equation and the heat equation. Either the case of singular or degenerate equations is considered. The initial datum $$u_0$$ u 0 is a summable function and a reaction term f is present in the problem. We prove that, despite the lack of regularity of $$u_0$$ u 0 , immediate regularization of the solutions appears for data f sufficiently regular and we derive estimates that for zero data f become the known decay estimates for these kinds of problems. Besides, even if f is not regular, we show that it is possible to describe the behavior in time of a suitable class of solutions. Finally, we establish some uniqueness results for the solutions of these evolution problems.

scholarly journals Fractional stochastic heat equation with piecewise constant coefficients

2020 ◽  
Vol 21 (01) ◽  
pp. 2150002
Author(s):  
Yuliya Mishura ◽  
Kostiantyn Ralchenko ◽  
Mounir Zili ◽  
Eya Zougar
Keyword(s):  
Diffusion Coefficient ◽  
Heat Equation ◽  
Divergence Form ◽  
Stochastic Heat Equation ◽  
Piecewise Constant ◽  
Constant Diffusion Coefficient ◽  
Infinite Dimensional ◽  
Order Elliptic Operator ◽  
Constant Diffusion ◽  
Constant Coefficients

We introduce a fractional stochastic heat equation with second-order elliptic operator in divergence form, having a piecewise constant diffusion coefficient, and driven by an infinite-dimensional fractional Brownian motion. We characterize the fundamental solution of its deterministic part, and prove the existence and the uniqueness of its solution.

scholarly journals Null controllability of a nonlinear heat equation

2002 ◽  
Vol 7 (7) ◽  
pp. 375-383 ◽  
Author(s):  
G. Aniculăesei ◽  
S. Aniţa
Keyword(s):  
Heat Equation ◽  
Dirichlet Boundary ◽  
Null Controllability ◽  
Carleman Estimates ◽  
Nonlinear Heat Equation ◽  
Homogeneous Dirichlet Boundary Condition ◽  
Linearized System ◽  
Kakutani Fixed Point ◽  
Exact Null Controllability ◽  
Kakutani Fixed Point Theorem

We study the internal exact null controllability of a nonlinear heat equation with homogeneous Dirichlet boundary condition. The method used combines the Kakutani fixed-point theorem and the Carleman estimates for the backward adjoint linearized system. The result extends to the case of boundary control.

scholarly journals Null controllability of the heat equation in pseudo-cylinders by an internal control

2020 ◽  
Vol 26 ◽  
pp. 122
Author(s):  
Jon Asier Bárcena-Petisco
Keyword(s):  
Heat Equation ◽  
Internal Control ◽  
Cylindrical Part ◽  
Null Controllability ◽  
Carleman Estimate ◽  
Main Difficulty ◽  
Absorption Properties ◽  
Weighted Function ◽  
Cylindrical Structure ◽  
Linear Heat

In this paper we prove the null controllability of the heat equation in domains with a cylindrical part and limited by a Lipschitz graph. The proof consists mainly on getting a Carleman estimate which presents the usual absorption properties. The main difficulty we face is the loss of existence of the usual weighted function in C2 smooth domains. In order to deal with this, we use its cylindrical structure and approximate the system by the same system stated in regular domains. Finally, we show some applications like the controllability of the semi-linear heat equation in those domains.

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