This paper deals with the exact controllability to the trajectories of the one--phase Stefan problem in one spatial dimension. This is a free-boundary problem that models solidification and melting processes. It is assumed that the physical domain is filled by a medium whose state is liquid on the left and solid, with constant temperature, on the right. In between we find a free-boundary (the interface that separates the liquid from the solid). In the liquid domain, a parabolic equation completed with initial and boundary conditions must be satisfied by the temperature. On the interface, an additional free-boundary requirement, called the {\it Stefan condition,} is imposed. We prove the local exact controllability to the (smooth) trajectories. To this purpose, we first reformulate the problem as the local null controllability of a coupled PDE-ODE system with distributed controls. Then, a new Carleman inequality for the adjoint of the linearized PDE-ODE system, coupled on the boundary through nonlocal in space and memory terms, is presented. This leads to the null controllability of an appropriate linear system. Finally, a local result is obtained via local inversion, by using {\it Liusternik-Graves' Theorem}. As a byproduct of our approach, we find that some parabolic equations which contains memory terms localized on the boundary are null-controllable.
Exact Controllability of Nonlinear Heat Equations in Spaces of Analytic Functions
利用Carleman估计可以建立非线性抛物型方程轨迹的可控性。然而，通过这种方法，并不清楚如何确定给定的函数是否确实是可达的。在Gevrey空间中，通过考虑一维非线性热方程，基于控制输入的直接方法研究了抛物型方程的可达状态.假设非线性部分是空间变量x、未知量y及其导数$\partial$ x y的解析函数。通过研究空间变量的非线性Cauchy问题和空间导数喷流与时间导数喷流之间的关系，得到了小初值和小终值下的精确能控性结果，该结果可推广为复平面上某个球上的解析函数. 2010年数学学科分类：35K40、93B05
Decay of solutions and bilinear control to trajectories of a 1D degenerate parabolic system
Universidade do Estado do Rio de Janeiro, Escola Politécnica（里约热内卢州立大学，理工学院）；Universidad Privada Boliviana, Departamento de Ciencias Exactas（玻利维亚私立大学，理学院）；Universidade do Estado do Rio de Janeiro, Instituto de Matemática e Estatística（里约热内卢州立大学，数学与统计研究所）；Universidade Federal Fluminense, Instituto de Matemática e Estatística（弗鲁米嫩塞联邦大学，数学与统计研究所）
