ON MESO-SCALE APPROXIMATIONS FOR VIBRATIONS OF MEMBRANES WITH LOWER-DIMENSIONAL CLUSTERS OF INERTIAL INCLUSIONS

Formal asymptotic algorithms are considered for a class of meso-scale approximations for problems of vibration of elastic membranes that contain clusters of small inertial inclusions distributed along contours of predefined smooth shapes. Effective transmission conditions have been identified for inertial structured interfaces, and approximations to solutions of eigenvalue problems have been derived for domains containing lower-dimensional clusters of inclusions

Second-order L2L^2-regularity in nonlinear elliptic problems

A second-order regularity theory is developed for solutions to a class of quasilinear elliptic equations in divergence form, including the $p$-Laplace equation, with merely square-integrable right-hand side. Our results amount to the existence and square integrability of the weak derivatives of the nonlinear expression of the gradient under the divergence operator. This provides a nonlinear counterpart of the classical $L^2$-coercivity theory for linear problems, which is missing in the existing literature. Both local and global estimates are established. The latter apply to solutions to either Dirichlet or Neumann boundary value problems. Minimal regularity on the boundary of the domain is required. If the domain is convex, no regularity of its boundary is needed at all

Sharp Fractional Hardy Inequalities in Half-Spaces

We determine the sharp constant in the Hardy inequality for fractional Sobolev spaces on half-spaces. Our proof relies on a non-linear and non-local version of the ground state representation.Comment: 6 pages; dedicated to V. G. Maz'y

Extended L p Dirichlet Spaces

(with R.Schilling) Extended L^p-Dirichlet spaces. In : Around the research of Vladimir Maz"ya, Vol.1. Ed. A.Laptev, Springer 2010, 221 - 238