Strong Ill-Posedness in ( boldsymbol{L}^{ boldsymbol{ infty }} ) of the 2D Boussinesq Equations in Vorticity Form and Application to the 3D Axisymmetric Euler Equations. - Roberta Bianchini; Lars Eric Hientzsch; Felice Iandoli (SIAM J. Math. Anal., 2024)