arXiv subjects
Publications and source records attributed to C. Spina.
We find necessary and sufficient conditions for the validity of weighted Rellich inequalities in Lp for functions in bounded domains vanishing at the boundary. General operators like L = Delta+ c\|x|^2x nabla-b\|x|^2 are considered. Critical cases and remainder terms are also investigated.
We prove L^p estimates for the Baouendi-Grushin operator L=Delta_x+|x|^\alpha Delta_y in L^p(R^N+M), 1 < p < 1, where x belongs to R^N; y belongs to R^M. When p = 2 more general weights belonging to Reverse Holder classes are allowed.
We show that a realization of the operator $L=|x|^αΔ+c|x|^{α-1}\frac{x}{|x|}\cdot\nabla -b|x|^{α-2}$ generates a semigroup in $L^p(\mathbb {R}^N)$ if and only if $D_c=b+(N-2+c)^2/4 > 0$ and $s_1+\min\{0,2-α\}<N/p<s_2+\max\{0,2-α\}$, where $s_i$ are the roots of the equation $b+s(N-2+c-s)=0$, or $D_c=0$ and $s_0+\min\{0,2-α\} \le N/p \le s_0+\max\{0,2-α\}$, where $s_0$ is the unique root of the above equation. The domain of the generator is also characterized.
We find necessary and sufficient conditions for the validity of weighted Rellich and Calderon-Zygmund inequalities in L^p, 1 \leq p \leq \infty, in the whole space and in the half-space with Dirichlet boundary conditions. General operators like L=Δ+c\frac{x}{|x|^2}\cdot\nabla-\frac{b}{|x|^2} are considered. We compute best constants in some situations.