Electronic Journal of Differential Equations,
Vol. 2019 (2019), No. 123, pp. 1-15.

Title: Null controllability of nonlinear control systems governed by
          coupled degenerate parabolic equations

Authors: Fengdan Xu (Jilin Univ., Changchun, China)
               Jingxue Yin  (South China Normal Univ., Guangzhou, China)
               Mingjun Zhou (Jilin Univ., Changchun, China)
               Qian Zhou.  (Jilin Univ., Changchun, China)

Abstract:
 This article concerns the null controllability of a nonlinear control system governed
 by coupled degenerate parabolic equations.
 We first establish the Carleman estimate and the observability inequality for 
 solutions to the conjugate problem.
 Then we can prove the observability inequality and the null controllability 
 of the linear control system. Finally, the nonlinear control system is shown 
 to be null controllable by a fixed point argument and compact estimates.
 
Submitted November 11, 2018. Published November 21, 2019.
Math Subject Classifications:  93B05, 93C20, 35K65.
Key Words: Null controllability; coupled degenerate parabolic equations; Carleman estimate.