| Abstract: |
| For the semilinear control system $y`(
t) =Ay( t) +f( y( t)) +Bu(t)$, where $B:U\rightarrow X$ is a linear continuous operator, $X$
and $U$ two Hilbert spaces, $A:D( A) \subseteq X\rightarrow X$
the generator of a C$_{0}$-semigroup, $f:X\rightarrow X$ a given function and $u
$ the control, we study the null controllability problem and we provide
estimates for the minimum time function around the target, using viability
results. |
|