Eigenvalue estimates and asymptotics for weighted pseudodifferential operators with singular measures in the critical case

In a domain $\Omega\subset \mathbb{R}^{\mathbf{N}}$ we consider a selfadjoint operator $\mathbf{T}=\mathfrak{A}^*P\mathfrak{A} ,$ where $\mathfrak{A}$ is a pseudodifferential operator of order $-l=-\mathbf{N}/2$ and $P=V\mu_{\Sigma}$ is a singular signed measure in $\Omega$ concentrated on a Lipschitz surface $\Sigma$ of dimension $d<\mathbf{N}$, absolutely continuous with respect to the surface measure $\mu_{\Sigma}$ on $\Sigma$. We establish eigenvalue estimates and asymptotics for this operator. It turns out that the order of these estimates and asymptotics is independent of the dimension $d$ of the surface. If there are several surfaces, possibly, of different dimensions, as well as an absolute continuous measure on $\Omega$ the corresponding asymptotic coefficients add up.