#### 13 Citations

Quasiaffinity and invariant subspaces

- Mathematics
- 2016

Special classes of intertwining transformations between Hilbert spaces are introduced and investigated, whose purposes are to provide partial answers to some classical questions on the existence of… Expand

El problema del subespacio invariante

- 2014

El famoso problema del subespacio invariante lleva más de 80 años sin tener una respuesta completa. En este trabajo hacemos un breve recuento de algunos resultados que se han obtenido con la… Expand

Lebesgue Measure on ℝ

- Computer Science
- 2014

The goal of the next two chapters is to develop a new form of integration that, while not perfect, overcomes many of the innate flaws of the Riemann integral. Expand

Sequences and Series of Functions

- Mathematics
- 2014

Sequences and series of functions are natural extensions of the topics discussed in Chaps. 2 and 3 and many of their properties are derived in a straightforward manner from the results covered there.… Expand

Sequences in ℝ

- Mathematics
- 2014

In this chapter we investigate the most basic concept of analysis, the limit of a sequence. The concepts of convergence and divergence will be the main focus of our discussion but we will also touch… Expand

The Real Numbers

- Computer Science
- 2014

To begin this study, the opening section provides a list of necessary preliminaries to develop a concrete foundation to support this intuitive understanding before progressing to a study of functions of a real variable. Expand

The Riemann Integral

- Mathematics
- 2014

Here we consider the familiar integral from calculus which is generally attributed to Riemann, though the idea of upper and lower sums for finding areas was used previously by Cauchy; other… Expand

Invariant subspaces for operators whose polynomials satisfy the (G1)-condition

- Mathematics
- 2013

Abstract In this note, we show that if T ∈ B ( H ) is such that p ( T ) satisfies the ( G 1 ) -condition for every polynomial p and if the outer boundary of the spectrum of T is a finite union of… Expand

The Levi-Civita equation, vector modules and spectral synthesis

- Mathematics
- 2013

The purpose of this paper is to give a survey on some recent results concerning spectral analysis and spectral synthesis in the framework of vector modulesand in close connection with the Levi-Civita… Expand

Spectral Analysis and Spectral Synthesis

- Mathematics
- 2012

Spectral analysis and spectral synthesis deal with the description of translation invariant function spaces over locally compact Abelian groups. One considers the space Open image in new window of… Expand

#### References

SHOWING 1-10 OF 34 REFERENCES

An operator not satisfying Lomonosov's hypothesis

- Mathematics
- 1980

Abstract An example is presented of a Hilbert space operator such that no non-scalar operator that commutes with it commutes with a non-zero compact operator. This shows that Lomonosov's invariant… Expand

Ten years in Hilbert space

- Mathematics
- 1979

This is a report on progress in the theory of single operators in the 1970's. It is based for the most part, but not exclusively, on ten problems in Hilbert space posed in 1970 [21]; it reports which… Expand

Some invariant subspaces for subnormal operators

- Mathematics
- 1978

A theorem of D.E. Sarason is used to show that all subnormal operators have nontrivial invariant subspaces if some very special subnormal operators have them. It is then shown that these special… Expand

A geometric equivalent of the invariant subspace problem

- Mathematics
- 1976

It is shown that every operator has an invariant subspace if and only if every pair of idempotents has a common invariant subspace. An idempotent on a Hilbert space is a bounded linear operator whose… Expand