abstract:
We study the Cauchy problem for the Kirchhoff equation
¥begin{equation}¥label{EQ:Kirchhoff}
¥left¥{
¥begin{aligned}
& ¥partial2t u-¥left(1+¥int{¥mathbb{R}n}
¥nabla u
2¥, dx¥right) ¥Delta u=0, &¥quad t>0, ¥quad x¥in ¥mathbb{R}n,¥¥
& u(0,x)=u0(x), ¥quad ¥partialt u(0,x)=u1(x),
&¥quad x ¥in ¥mathbb{R}n.
¥end{aligned}¥right.
¥end{equation}
Global existence results for ¥eqref{EQ:Kirchhoff} in an appropriate class are known for initial data $u0, u1$
that are either small in some Sobolev space or analytic or quasi-analytic (in this case, $u0$
and $u1$ can be arbitrarily large). In this talk, we consider the case of
initial data in the Gevrey class of $L2$ type. We inform that if a certain explicit condition
is satisfied, involving the time $T$, the size of $u0$ and $u1$, and their regularity, then the
Cauchy problem ¥eqref{EQ:Kirchhoff} has a unique solution on the interval $0, T$ (in an appropriate
class). The proof relies, in particular, on energy estimates for solutions of
the equation
$$
¥partial2t u- c(t) ¥Delta u=0.
$$
This talk is baed on the jopint work with Professor Michael Ruzhansky (Ghent University).
¥begin{thebibliography}{99} ¥bibitem{MR-JAM} T. Matsuyama and M. Ruzhansky, {¥em On the Gevrey well-posedness of the Kirchhoff equation,} J. Anal. Math. {¥bf 137} (2019), 449--468. ¥end{thebibliography}
Talk