Electronic Journal of Differential Equations,
Vol. 2019 (2019), No. 103, pp. 1-12.

Title: Null controllability of a coupled system of degenerate parabolic 
       equations with lower order terms

Authors: Jianing Xu   (Jilin Univ., Changchun, China)
         Qian Zhou    (Jilin Univ., Changchun, China)
         Yuanyuan Nie (Jilin Univ., Changchun, China)

Abstract:
 This article concerns the null controllability of a control system
 governed by coupled degenerate parabolic equations with lower order terms.
 For these equations, the convection terms cannot be controlled by the diffusion
 terms.  We establish a Carleman estimate and an observability inequality
 by using  Carleman estimates for single degenerate parabolic equations with
 lower order term  and some energy estimates.
 Then we prove that the system with two controls is null controllable.
 Finally, we show the null controllability of the system with one control,
 by constructing suitable controls.

Submitted July 9, 2018. Published September 06, 2019.
Math Subject Classifications: 93B05, 93C20, 35K65.
Key Words: Carleman estimate; null controllability; coupled degenerate equations; 
           convection terms.