Semilinear equations

Glueing a peak to a non-zero limiting profile for a critical Moser–Trudinger equation

Druet proved that for any given sequence of Moser–Trudinger type nonlinearities with critical growth, and any sequence of solutions to the corresponding semilinear problem for the laplacian operator which converges weakly in H^1_0 to some u_∞, then the Dirichlet energy is quantified, namely there exists an integer N≥0 such that the energy of the solutions converges to 4πN plus the Dirichlet energy of u_∞. As a crucial step to get the general existence results of [7], it was more recently proved in [8] that, for a specific class of nonlinearities (see (2)), the loss of compactness (i.e.

Definition, existence, stability and uniqueness of the solution to a semilinear elliptic problem with a strong singularity at u = 0

In this paper we consider a semilinear elliptic equation with a strong singularity at $u=0$, namely
\begin{equation*}
\begin{cases}
\dys u\geq 0 & \mbox{in } \Omega,\\
\displaystyle - div \,A(x) D u = F(x,u)& \mbox{in} \; \Omega,\\
u = 0 & \mbox{on} \; \partial \Omega,\\
\end{cases}
\end{equation*}
with $F(x,s)$ a Carath\'eodory function such that
$$
0\leq F(x,s)\leq \frac{h(x)}{\Gamma(s)}\,\,\mbox{ a.e. } x\in\Omega,\, \forall s>0,
$$

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