The Fujita exponent across an interface

Mohamed Majdoub, Ezzedine Mliki

We consider the semilinear parabolic equation \[ \partial_t u = Δu + 2\mathfrak{q}\,δ_{\mathbb{S}}\,\nabla u + |u|^{p-1}u \qquad \text{in } (0,\infty)\times\mathbb{R}^N, \] where $…