Invariant Subspaces
Mostrando 1-8 de 8 artigos, teses e dissertações.
-
1. REMARKS ABOUT THE INVARIAN SUBSPACE PROBLEM / CONSIDERAÇÕES SOBRE O PROBLEMA DO SUBESPAÇO INVARIANTE
The Invariant Subspace Problem is the most important open question in Operator Theory. Although, there are many partial results, the question remains open for operators on complex, infinite-dimensional, separable Hilbert spaces. To prove that every operator has a non-trivial invariant subspace might be the beginning of a general structure theory for Hilbert
Publicado em: 2011
-
2. PARAMETRIC IDENTIFICATION OF MECHANICAL SYSTEMS USING SUBSPACE ALGORITHMS / IDENTIFICAÇÃO PARAMÉTRICA DE SISTEMAS MECÂNICOS USANDO ALGORITMOS DE SUBESPAÇO
Parametric identification of mechanical systems is one of the main applications of the system identification techniques in Mechanical Engineering, specifically for the identification of modal parameters of flexible structures. One of the main problems in the identification is the presence of noise in the measurements. This work presents an analysis in the pr
Publicado em: 2003
-
3. Symplectic integrators revisited
This paper is a survey on Symplectic Integrator Algorithms (SIA): numerical integrators designed for Hamiltonian systems. As it is well known, n degrees of freedom Hamiltonian systems have an important property: their ows preserve not only the total volume of the phase space, which is only one of the Poincaré invariants, but also the volume of sub-spaces le
Brazilian Journal of Physics. Publicado em: 2002-12
-
4. SUBESPAÇOS INVARIANTES PARA OPERADORES HIPONORMAIS / INVARIANT SUBSPACES FOR HIPONORMAL OPERATORS
O problema do subespaço invariante consiste na seguinte pergunta: será que todo operador (i.e., transformação linear limitada) atuando em um espaço de Hilbert separável (complexo de dimensão infinita) tem subespaço invariante nãotrivial? Este é, possivelmente, o mais importante problema em aberto na teoria de operadores. Em particular, o problema d
Publicado em: 2002
-
5. STABILITY FOR DISCRETE LINEAR SYSTEMS IN HILBERT SPACES / ESTABILIDADE DE SISTEMAS LINEARES DISCRETOS EM ESPAÇOS DE HILBERT
Este trabalho aborda o problema da estabilidade de sistemas lineares, invariantes no tempo, a tempo discreto, com o espaço de estado sendo um espaço de Hilbert complexo e separável de dimensão infinita. São investigadas condições necessárias e/ou suficientes para quatro conceitos diferentes de estabilidade: estabilidade assintótica uniforme e estabi
Publicado em: 1988
-
6. An Invariant for Certain Operator Algebras
It is shown that the so-called principal function invariant, which is associated in a unitarily invariant way to operators with trace class self commutator TT* - T*T, is invariant under trace class perturbations of T and is an extension of the index of T-z to the whole plane. The connection of the principal function, under additional hypothesis, with the det
-
7. Invariants of sets of linear varieties.
A minimal set of generators of the ring of invariants for four linear subspaces of dimension n in a vector space of dimension 2n is computed, using the symbolic method introduced by Grosshans et al. [Grosshans, F., Rota, G.-C. & Stein, J. A. (1987) Invariant Theory and Superalgebras (Am. Math. Soc., Providence, RI)].
-
8. Is the cygnet the quintessential baryon?
The apparently new hadron-like particle ("cygnet") indicated by cosmic ray observations on certain neutron stars is predicted to be a spin 1/2 fermion of magnetic moment and charge 0 and lifetime infinity. This derives from the natural identification of the cygnet with the one hitherto unobserved fundamental fermion of chronometric particle theory, the x or