Null-Controllability of 1-D parabolic equations

具有梯度相关系数的拟线性抛物方程的零能控性

Null controllability of quasilinear parabolic equations with gradient dependent coefficients

本文研究含梯度相关系数的拟线性抛物方程零能控性，借助线性问题的正则控制与不动点策略证明近似零能控，并对含抛物 $p$-Laplacian 的情形证明任意小时间精确零能控，且用有限元数值验证。

Boundary null controllability of degenerate heat equation as the limit of internal controllability

In this paper, we recover the boundary null controllability for the degenerate heat equation by analyzing the asymptotic behavior of an eligible family of state-control pairs $((u_{\varepsilon}, h_{\varepsilon}))_{\varepsilon >0}$ solving corresponding singularly perturbed internal null controllability problems. As in other situations studied in the literature, our approach relies on Carleman estimates and meticulous weak convergence results. However, for the degenerate parabolic case, some specific trace operator inequalities must be obtained, in order to justify correctly the passage to the …

无额外力的动态边界条件前向随机抛物方程的可控性

Controllability for forward stochastic parabolic equations with dynamic boundary conditions without extra forces

本文研究动态边界条件下前向随机抛物方程的可控性，通过谱不等式和迭代策略建立可观测性，进而证明零可控性和近似可控性。

带动态边界条件的抛物型系统的可控性与反问题

Controllability and Inverse Problems for Parabolic Systems with Dynamic Boundary Conditions

本文是一篇综述，梳理带动态边界条件的抛物型系统零可控性与反问题的研究成果，阐释Carleman估计等经典方法的推广应用，分析其相较静态边界条件的难点，并给出结论与开放问题。

Null controllability for the singular heat equation with a memory term

In this paper we focus on the null controllability problem for the heat equation with the so-called inverse square potential and a memory term. To this aim, we first establish the null controllability for a nonhomogeneous singular heat equation by a new Carleman inequality with weights which do not blow up at t=0. Then the null controllability property is proved for the singular heat equation with memory under a condition on the kernel, by means of Kakutani's fixed-point Theorem.

Null-controllability, exact controllability, and stabilization of hyperbolic systems for the optimal time

In this paper, we discuss our recent works on the null-controllability, the exact controllability, and the stabilization of linear hyperbolic systems in one dimensional space using boundary controls on one side for the optimal time. Under precise and generic assumptions on the boundary conditions on the other side, we first obtain the optimal time for the null and the exact controllability for these systems for a generic source term. We then prove the null-controllability and the exact controllability for any time greater than the optimal time and for any source term. Finally, for homogeneous …

Nonnegative controllability for a class of nonlinear degenerate parabolic equations with application to climate science

Let us consider a nonlinear degenerate reaction-diffusion equation with application to climate science. After proving that the solution remains nonnegative at any time, when the initial state is nonnegative, we prove the approximate controllability between nonnegative states at any time via multiplicative controls, that is, using as control the reaction coefficient.

Approximate controllability for nonlinear degenerate parabolic problems with bilinear control

In this paper, we study the global approximate multiplicative controllability for nonlinear degenerate parabolic Cauchy-Neumann problems. First, we will obtain embedding results for weighted Sobolev spaces, that have proved decisive in reaching well-posedness for nonlinear degenerate problems. Then, we show that the above systems can be steered in $L^2$ from any nonzero, nonnegative initial state into any neighborhood of any desirable nonnegative target-state by bilinear piecewise static controls. Moreover, we extend the above result relaxing the sign constraint on the initial date.

具有 Robin 边界条件的随机抛物型方程的零能控性

Null controllability for stochastic parabolic equations with Robin boundary conditions

本文研究带线性 Robin 边界条件且含零阶、一阶有界系数项的正反向线性随机抛物型方程，通过对偶方法为负 Sobolev 空间中的伴随方程弱解建立两个新的全局 Carleman 估计，从而证明其零能控性。

Null controllability of the structurally damped wave equation with moving point control

We investigate the internal controllability of the wave equation with structural damping on the one dimensional torus. We assume that the control is acting on a moving point or on a moving small interval with a constant velocity. We prove that the null controllability holds in some suitable Sobolev space and after a fixed positive time independent of the initial conditions.

一类一维退化抛物方程自由边界问题的局部可控性

Local controllability of a free-boundary problem for a class of one-dimensional degenerate parabolic equations

本文研究了一类一维退化抛物方程自由边界问题的局部可控性，证明了在初始状态足够小的情况下，存在控件可将系统状态在指定时间驱动到零。

Robust Stackelberg controllability for a parabolic equation

The aim of this paper is to perform a Stackelberg strategy to control parabolic equations. We have one control, \textit{the leader}, that is responsible for a null controllability property; additionally, we have a control \textit{the follower} that solves a robust control objective. That means, that we seek for a saddle point of a cost functional. In this way, the follower control is not sensitive to a broad class of external disturbances. As far as we know, the idea of combining robustness with a Stackelberg strategy is new in literature

阻尼非线性波动方程的零能控性

Null controllability of damped nonlinear wave equation

本文研究阻尼非线性波动方程的零能控性，利用 Galerkin 方法、不动点定理和新迭代方法，分别建立了半线性、拟线性及完全非线性波动系统的零能控性结果。

带记忆项的Stokes方程的非零能控性

Non null controllability of Stokes equations with memory

本文研究带记忆项的三维Stokes方程的零能控性，构造出使零能控性不成立的初始条件，并证明该否定结果对边界控制和分布控制均成立。

随机抛物型方程的Stackelberg-Nash零能控性

Stackelberg-Nash null controllability for stochastic parabolic equations

本文研究了含梯度项的随机抛物型方程的分层控制问题，采用双领导者与双跟随者的Stackelberg-Nash策略，通过Carleman估计建立能观性不等式，实现了耦合前向-后向随机系统的零能控性。

Null Controllability of the Kuramoto-Sivashinsky Equation on star-shaped trees

In this paper we treat controllability properties for the linear Kuramoto-Sivashinsky equation on a network with two types of boundary conditions. More precisely, the equation is considered on a star-shaped tree with Dirichlet and Neumann boundary conditions. By using the moment theory we can derive null-controllability properties with boundary controls acting on the external vertices of the tree. In particular, the controllability holds if the anti-diffusion parameter of the involved equation does not belong to a critical countable set of real numbers. We point out that the critical set for w…

某些控制作用于域的不同部分及其边界的线性抛物系统的零能控性

Null-controllability for some linear parabolic systems with controls acting on different parts of the domain and its boundary

本文研究常系数线性抛物系统在多个控制作用于不同子域及边界时的零能控性，证明了一维Kalman秩条件，并建立了Carleman估计。

指数 Dirichlet 级数的解析性及其在抛物方程近似能控性中的应用

Analyticity of Exponential Dirichlet Series and Applications to the Approximate Controllability of Parabolic Equations

本文研究一类指数 Dirichlet 级数的解析性、幂级数系数及余项估计，并将其用于矩量法，证明线性抛物方程在局部分布或集中控制下的近似能控性。

Discrete Carleman estimates and application to controllability for a fully-discrete parabolic operator with dynamic boundary conditions

We consider a fully-discrete approximations of 1-D heat equation with dynamic boundary conditions for which we provide a controllability result. The proof of this result is based on a relaxed observability inequality for the corresponding adjoint system. This is done by using a suitable Carleman estimate for such models where the discrete parameters $h$ and $Δt$ are connected to the one of the large Carleman parameters.

带 Robin 边界条件的一维退化抛物型方程的边界可控性

Boundary controllability for a 1D degenerate parabolic equation with a Robin boundary condition

本文研究左端点带加权 Robin 边界条件且势函数具有奇异性的一维退化抛物型方程，利用奇异 Sturm-Liouville 理论、Fourier-Dini 展开和矩方法证明零可控性，并给出可控性代价的上下界估计。

具有动态边界条件的立方Ginzburg-Landau方程的局部零能控性

Local null controllability of a cubic Ginzburg-Landau equation with dynamic boundary conditions

本文研究了具有动态边界条件的立方Ginzburg-Landau方程，通过单一控制、线性化、对偶方法、Carleman估计及反函数定理，证明了该非线性系统的局部零能控性。

An elementary proof of the lack of null controllability for the heat equation on the half line

In this note, we give an elementary proof of the lack of null controllability for the heat equation on the half line by employing the machinery inherited by the unified transform, known also as the Fokas method. This approach also extends in a uniform way to higher dimensions and different initial-boundary value problems governed by the heat equation, suggesting a novel methodology for studying problems related to controllability.

退化波动方程的边界零能控性作为内部能控性的极限

Boundary null controllability of degenerate wave equation as the limit of internal controllability

通过分析内部零能控性问题的状态-控制对族，建立显式依赖于ε的观测不等式，证明退化波动方程边界零能控性。

Statistical null-controllability of stochastic nonlinear parabolic equations

In this paper, we consider forward stochastic nonlinear parabolic equations, with a control localized in the drift term. Under suitable assumptions, we prove the small-time global null-controllability, with a truncated nonlinearity. We also prove the statistical local null-controllability of the true system. The proof relies on a precise estimation of the cost of null-controllability of the stochastic heat equation and on an adaptation of the source term method to the stochastic setting. The main difficulty comes from the estimation of the nonlinearity in the fixed point argument due to the la…

Impulse null approximate controllability for heat equation with dynamic boundary conditions

The main purpose of this article is to prove a logarithmic convexity estimate for the solution of a linear heat equation subject to dynamic boundary conditions in a bounded convex domain. As an application, we prove the impulsive null approximate controllability for an impulsive heat equation with dynamic boundary conditions.

Null Controllability of a nonlinear age, space and two-sex structured population dynamics model

In this paper, we study the null controllability of a nonlinear age, space and two-sex structured population dynamics model. This model is such that the nonlinearity and the couplage are at birth level. We consider a population with males and females and we are dealing with two cases of null controllability problem. The first problem is related to the total extinction, which means that, we estimate a time $T$ to bring the male and female subpopulation density to zero. The second case concerns null controllability of male or female subpopulation individuals. Here, So if $A$ is the life span of …

Uncertainty principles in Gelfand-Shilov spaces and null-controllability

We provide new uncertainty principles for functions in a general class of Gelfand-Shilov spaces. These results apply, in particular, with the classical Gelfand-Shilov spaces as well as for spaces of functions with weighted Hermite expansions. Thanks to these uncertainty principles, we derive null-controllability results for evolution equations with adjoint systems enjoying smoothing effects in specific Gelfand-Shilov spaces. More precisely, we consider control subsets which are thick with respect to a quasi linearly growing density and establish sufficient conditions on the growth of the densi…

Approximate controllability of nonlinear parabolic PDEs in arbitrary space dimension

In this paper, we consider a parabolic PDE on a torus of arbitrary dimension. The nonlinear term is a smooth function of polynomial growth of any degree. In this general setting, the corresponding Cauchy problem is not necessarily well posed. We show that the equation in question is approximately controllable by only a finite number of Fourier modes. This result is proved by using some ideas from the geometric control theory introduced by Agrachev and Sarychev.

具有奇异势的四阶退化抛物型方程的边界能控性

Boundary controllability for a fourth order degenerate parabolic equation with a singular potential

本文研究带奇异势的一维四阶退化抛物型方程在左端点边界控制下的零能控性，利用 Bessel 函数谱分解、半群理论和矩方法给出能控性代价的上下界估计。

Remark on the global null controllability for a viscous Burgers-particle system with particle supported control

This paper is devoted to study the controllability of a one-dimensional fluid-particle interaction model where the fluid follows the viscous Burgers equation and the point mass obeys Newton's second law. We prove the null controllability for the velocity of the fluid and the particle and an approximate controllability for the position of the particle with a control variable acting only on the particle. One of the novelties of our work is the fact that we achieve this controllability result in a uniform time for all initial data and without any smallness assumptions on the initial data.

Null-controllability properties of the generalized two-dimensional Baouendi-Grushin equation with non-rectangular control sets

We consider the null-controllability problem for the generalized Baouendi-Grushin equation $(\partial_t - \partial_x^2 - q(x)^2\partial_y^2)f = 1_ωu$ on a rectangular domain. Sharp controllability results already exist when the control domain $ω$ is a vertical strip, or when $q(x) = x$. In this article, we provide upper and lower bounds for the minimal time of null-controllability for general $q$ and non-rectangular control region $ω$. In some geometries for $ω$, the upper bound and the lower bound are equal, in which case, we know the exact value of the minimal time of null-controllability. O…

Grushin-like热方程在2D流形上的非可控性性质

Non null-controllability properties of the Grushin-like heat equation on 2D-manifolds

研究Grushin-like热方程在二维流形上的非可控性性质，探讨其在存在内部奇点情况下的可控性条件及时间要求。

2x2非线性退化抛物系统通过单一边界控制力的可控性

Controllability for a 2x2 nonlinear degenerate parabolic system via one boundary control force

本文研究两个退化抛物方程组成的非线性系统，通过单一边界控制力，利用矩方法和迭代法证明了局部精确边界可控性到零，并给出了控制成本估计。

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

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.

On the null-controllability of the heat equation in unbounded domains

We make two remarks about the null-controllability of the heat equation with Dirichlet condition in unbounded domains. Firstly, we give a geometric necessary condition (for interior null-controllability in the Euclidean setting)which implies that one can not go infinitely far away from the control region without tending to the boundary (if any), but also applies when the distance to the control region is bounded. The proof builds on heat kernel estimates. Secondly, we describe a class of null-controllable heat equations on unbounded product domains. Elementary examples include an infinite stri…

半线性波动方程正则解附近的局部能控性与散射解的零能控性

Local controllability around a regular solution and null-controllability of scattering solutions for semilinear wave equations

本文研究半线性波动与 Klein-Gordon 方程，在几何控制条件下证明部分解析解及部分爆破解附近的局部能控性，并利用局部能量衰减和全局 Strichartz 估计建立小维数非捕获外域散射解的零能控性。

具有延迟效应的热方程的记忆型零能控性

Observability and Null Controllability for Parabolic Systems with Delay and Memory

本文研究了同时包含记忆和延迟效应的发展方程的零能控性问题，采用延迟与记忆型零能控性概念，利用对偶论证、Carleman估计和移动控制策略推导出实现能控性的充分条件，并通过数值模拟验证了理论结果。

小时间全局可控性的一类双线性四阶抛物方程

Small-time global controllability of a class of bilinear fourth-order parabolic equations

本文研究了一类双线性四阶抛物方程的小时间全局可控性，通过几何控制方法和固定点论证，实现了状态的精确控制。

Exact controllability to the ground state solution for evolution equations of parabolic type via bilinear control

In a separable Hilbert space $X$, we study the linear evolution equation \begin{equation*} u'(t)+Au(t)+p(t)Bu(t)=0, \end{equation*} where $A$ is an accretive self-adjoint linear operator, $B$ is a bounded linear operator on $X$, and $p\in L^2_{loc}(0,+\infty)$ is a bilinear control. We give sufficient conditions in order for the above control system to be locally controllable to the ground state solution, that is, the solution of the free equation ($p\equiv0$) starting from the ground state of $A$. We also derive global controllability results in large time and discuss applications to paraboli…

Stackelberg exact controllability of a class of nonlocal parabolic equations

This paper deals with a multi-objective control problem for a class of nonlocal parabolic equations, where the non-locality is expressed through an integral kernel. We present the Stackelberg strategy that combines the concepts of controllability to trajectories with optimal control. The strategy involves two controls: a main control (the leader) and a secondary control (the follower). The leader solves a controllability to trajectories problem which consists to drive the state of the system to a prescribed target at a final time while the follower solves an optimal control problem which consi…

有限时间内粘性Burgers系统的局部零能控性

On the local null controllability of a viscous Burgers' system in finite time

本文证明在零Dirichlet边界条件下，有界区间上的粘性Burgers控制系统在有限时间内不具备局部零能控性，方法受KdV系统能控性研究启发，与Marbach的方法不同。

具有Hardy势的抛物方程的分层精确可控性

Hierarchical exact controllability for a parabolic equation with Hardy potential

本文通过Stackelberg-Nash策略研究具有Hardy势的抛物方程的分层精确可控性，在线性和半线性情形下分别利用Carleman不等式和不动点定理证明了领导者的存在性。

Null controllability for stochastic fourth order parabolic equations

We establish the null controllability for linear stochastic fourth order parabolic equations. Utilizing the duality argument, the null controllability is reduced to the observability for backward fourth order stochastic parabolic equations, and the desired observability estimate is obtained by a new global Carleman estimate. Our Carleman estimate is based on a new fundamental identity for a stochastic fourth order parabolic operator.

Null controllability of the 1D heat equation using flatness

We derive in a straightforward way the null controllability of a 1-D heat equation with boundary control. We use the so-called {\em flatness approach}, which consists in parameterizing the solution and the control by the derivatives of a "flat output". This provides an explicit control law achieving the exact steering to zero. We also give accurate error estimates when the various series involved are replaced by their partial sums, which is paramount for an actual numerical scheme. Numerical experiments demonstrate the relevance of the approach.

Local Exact Controllability of a Parabolic System of Chemotaxis

This paper studies the controllability problem of a parabolic system of chemotaxis. The local exact controllability to trajectories of the system imposed one control force only is obtained by applying Kakutani's fixed point theorem combined with the null controllability of the associated linearized parabolic system. The control function is shown to be in $L^\infty(Q)$, which is estimated by using the methods of maximal regularity and $L^p$-$L^q$ estimates of parabolic equations.

Approximate null-controllability with uniform cost for the hypoelliptic Ornstein-Uhlenbeck equations

We prove that the approximate null-controllability with uniform cost of the hypoelliptic Ornstein-Uhlenbeck equations posed on $\mathbb R^n$ is characterized by an integral thickness geometric condition on the control supports. We also provide associated quantitative weak observability estimates. This result for the hypoelliptic Ornstein-Uhlenbeck equations is deduced from the same study for a large class of non-autonomous elliptic equations from moving control supports. We generalize in particular results known for parabolic equations posed on $\mathbb R^n$, for which the approximate null-con…

Exact controllability to eigensolutions for evolution equations of parabolic type via bilinear control

In a separable Hilbert space $X$, we study the controlled evolution equation \begin{equation*} u'(t)+Au(t)+p(t)Bu(t)=0, \end{equation*} where $A\geq-σI$ ($σ\geq0$) is a self-adjoint linear operator, $B$ is a bounded linear operator on $X$, and $p\in L^2_{loc}(0,+\infty)$ is a bilinear control. We give sufficient conditions in order for the above nonlinear control system to be locally controllable to the $j$th eigensolution for any $j\geq1$. We also derive semi-global controllability results in large time and discuss applications to parabolic equations in low space dimension. Our method is cons…

球面上的Logvinenko-Sereda-Kovrijkine型不等式及球面上热方程的零能控性

Spherical Logvinenko-Sereda-Kovrijkine type inequality and null-controllability of the heat equation on the sphere

本文证明了球面上多项式的Logvinenko-Sereda-Kovrijkine型不等式，由此导出Laplace-Beltrami算子的谱不等式，并得出球面热方程在大小时间区间内控制成本均尖锐的零能控性结论。

具有非局部系数的退化抛物方程的分层零能控性

Hierarchical null controllability of a degenerate parabolic equation with nonlocal coefficient

本文针对扩散系数为空间退化函数与非局部项乘积的抛物方程，采用Stackelberg-Nash策略结合卡尔曼估计与Liusternik逆函数定理，证明其局部零能控性，解决了非局部系数导致的乘法耦合计算问题。

Stokes系统null可控性的最优成本及其应用

Optimal cost for the null controllability of the Stokes system with controls having $n-1$ components and applications

本文研究了Stokes系统在n-1个控制分量下的null可控性最优成本，证明其与n个控制分量时的成本阶数相同，并给出了应用。

某些线性抛物型系统的边界近似可控性

Boundary approximate controllability of some linear parabolic systems

本文研究两类线性抛物型系统的边界近似可控性，提出充分条件并证明一维单控制下的必要性，给出矩形域刻画，并构造分布可控但边界不可控的级联系统。

Small-time global null controllability of generalized Burgers' equations

In this paper, we study the small-time global null controllability of the generalized Burgers' equations $y_t + γ|y|^{γ-1}y_x-y_{xx}=u(t)$ on the segment $[0,1]$. The scalar control $u(t)$ is uniform in space and plays a role similar to the pressure in higher dimension. We set a right Dirichlet boundary condition $y(t,1)=0$, and allow a left boundary control $y(t,0)=v(t)$. Under the assumption $γ>3/2$ we prove that the system is small-time global null controllable. Our proof relies on the return method and a careful analysis of the shape and dissipation of a boundary layer.

Boundary null controllability for the heat equation with dynamic boundary conditions

In this paper, we are concerned with the boundary controllability of heat equation with dynamic boundary conditions. More precisely, we prove that the equation is null controllable at any positive time by means of a boundary control supported on an arbitrary subboundary. The proof of the main result combines a new boundary Carleman estimate and some regularity estimates for the adjoint system, with an explicit dependence with respect to the final time. This technique allows us to overcome a new difficulty that arises when absorbing a normal derivative term.

Stabilization and approximate null-controllability for a large class of diffusive equations from thick control supports

We prove that the thickness property is a necessary and sufficient geometric condition that ensures the (rapid) stabilization or the approximate null-controllability with uniform cost of a large class of evolution equations posed on the whole space $\mathbb R^n$. These equations are associated with operators of the form $F(\vert D_x\vert)$, the function $F:[0,+\infty)\rightarrow\mathbb R$ being continuous and bounded from below. We also provide explicit feedbacks and constants associated with these stabilization properties. The notion of thickness is known to be a necessary and sufficient cond…