Operadores uniformes estables y subespacios invariantes

Este trabajo estudia operadores uniformemente estables sobre espacios de Banach en general, con el propósito de caracterizar algunos que tengan subespacios invariantes no triviales. Palabras clave: Operadores Uniformemente estables, subespacios invariantes. Abstract: This paper studies uniformly stable operators on Banach spaces in general, with the purpose of characterizing some that have non-trivial invariant subspaces. Key words: Uniformly stable operators, sub invariant spaces

A Uniformly Stable Nonconforming FEM Based on Weighted Interior Penalties for Darcy-Stokes-Brinkman Equations

A nonconforming rectangular finite element method is proposed to solve a fluid structure interaction problem characterized by the Darcy-Stokes-Brinkman Equation with discontinuous coefficients across the interface of different structures. A uniformly stable mixed finite element together with Nitsche-type matching conditions that automatically adapt to the coupling of different sub-problem combinations are utilized in the discrete algorithm. Compared with other finite element methods in the literature, the new method has some distinguished advantages and features. The Boland-Nicolaides trick is used in proving the inf-sup condition for the multidomain discrete problem. Optimal error estimates are derived for the coupled problem by analyzing the approximation errors and the consistency errors. Numerical examples are also provided to confirm the theoretical results.