Let S be a closed subspace of a Hilbert space H and A a bounded linear selfadjoint operator on H. In this note, we show that the existence of A -selfadjoint projections with range S is related to some properties of shorted ...

A preconditioner for iterative solution of the interface problem in Schur Complement Domain Decomposition Methods is presented. This preconditioner is based on solving a global problem in a narrow strip around the interface. ...

As a more extensive issue, this paper deals with the polysemy attested in all Romance languages between interrogative pronouns and subordination markers in complex sentences. It investigates, specifically, the behavior of ...

In many countries, photodynamic therapy (PDT) has been recognized as a standard treatment for malignant conditions (for example, esophageal and lung cancers) and non-malignant ones such as age-related macular degeneration ...

A fine-tuned activation and deactivation of proteases and their inhibitors are involved in the execution of the inflammatory response. The zymogen/proenzyme plasminogen is converted to the serine protease plasmin, a ...

Given a Hermitian matrices A∈C^n×n and D∈C^m×m, and k > 0, we characterize under which conditions there exists a matrix K∈C^n×m with ∥K∥ < k such that the non-Hermitian block-matrix [AK∗A−AKD] has a positive (semi-) definite ...