BERNAL GONZÁLEZ , Luis

In this note, is proved that every member of a wide class of Banach spaces supports a sequence (Tn) of operators with a hereditary hypercyclic subsequence (Tnk) such that (Tn) itself does not satisfy the so-called Hypercyclicity Criterion and such that, in addition, the norms of the Tn's are controlled in a certain natural sense.

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We prove in this paper that, given α ∈ (0, 1/2), there exists a linear manifold M of entire functions satisfying that M is dense in the space of all entire functions and, in addition, limz→∞ exp(|z|α) f(j)(z) = 0 on any plane strip for every f ∈ M and for every derivation index j. Moreover, it is shown the existence of an entire function with...

We prove that, given a sequence of points in a complex domain Ω without accumulation points, there are functions having prescribed values at the points of the sequence and, simultaneously, having dense orbit in the space of holomorphic functions on Ω. The orbit is taken with respect to any fixed non-scalar differential operator generated by an...

In this paper, we provide some extensions of earlier results about hypercyclicity of some operators on the Fréchet space of entire functions of several complex variables. Specifically, we generalize in several directions a theorem about hypercyclicity of certain infinite order linear differential operators with constant coefficients and study...

We prove in this note that, given a simply connected domain G in the complex plane and a sequence of infinite order linear differential operators generated by entire functions of subexponential type satisfying suitable conditions, then there are holomorphic functions f on G such that the image of any open subset under the action of those...

In this paper, we essay a generalization of the classical concept of growth order of an entire function. We define the new parameter ρg(f), the relative growth order of f(z) with respect to g(z), which establishes a direct comparison between the growth of the moduli of two nonconstant entire functions f and g. Diverse properties, relative to...

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In this paper, the linear structure of the family He(G) of holomorphic functions in a domain G of the complex plane that are not analytically continuable beyond the boundary of G is analyzed. We prove that He(G) contains, except for zero, a dense algebra; and, under appropriate conditions, the subfamily of He(G) consisting of boundary-regular...

Necessary/sufficient conditions for a sequence of automorphisms of the complex plane to generate a sequence of composition operators that is universal on the punctured plane are provided. As a consequence, it is derived that only for translations and rotation-dilations there can be entire functions whose orbits present universality. Boundedness...

We prove in this paper the following result which extends in a somewhat 'linear' sense a theorem by Kierst and Szpilrajn and which holds on many 'natural' spaces of holomorphic functions in the open unit disk D: There exist a dense linear manifold and a closed infinite-dimensional linear manifold of holomorphic functions in D whose domain of...

In this paper we show that, given two double sequences of positive real numbers, α and β, the subset of all functions defined on an open real set which have big derivatives and small ones with respect to α and β, at every point, is residual in C∞. As a corollary, we derive that Baire-almost every function of C∞ has null radius of convergence at...

In this paper, a criterion for the existence of large linear algebras consisting, except for zero, of one-to-one operators on an infinite dimensional Banach space is provided. As a consequence, it is shown that every separable infinite dimensional Banach space supports a commutative infinitely generated free linear algebra of operators all of...

We provide sharp conditions on a measure µ defined on a measurable space X guaranteeing that the family of functions in the Lebesgue space Lp (µ, X) (p ≥ 1) which are not integrable with order q for any q > p (or any q < p) contains, except for zero, large subspaces of Lp (µ, X). This improves recent results due to Aron, García, Muñoz,...

In this paper we study the universality of (cnTn) where (cn) is a scalar sequence and (Tn) is a universal sequence such that Tn is valued in a topological vector space. We also show that if T is a hypercyclic operator on a Baire metrizable complex locally convex space then there exists a residual subset in the unit circle such that T is also...

We prove the existence of a residual set of entire functions, all of whose members are hypercyclic for every nonzero scalar multiple of T, where T is the differential operator associated to an entire function of order less than 1/2. The same result holds if T is a finite-order linear differential operator with non-constant coefficients.

In this paper we consider spaces of sequences which are valued in a topological space E and study generalized backward shifts associated to certain selfmappings of E. We characterize their universality in terms of dynamical properties of the underlying selfmappings. Applications to hypercyclicity theory are given. In particular, Rolewicz's...

In this paper the affine endomorphisms of C N which support compositionally universal entire functions are completely characterized.

We prove in this note that, given α ∈ (0, 1/2), there exists a linear manifold M of entire functions satisfying that M is dense in the space of all entire functions such that limz→∞ exp(|z|α)f(j)(z) = 0 on any plane strip for every f ∈ M and for every derivation index j. Moreover, the growth index of each nonnull function of M is infinite with...

In this paper a new sort of operators, the Taylor shifts, is introduced. They appear as a generalization of weighted backward shifts on the spaces of entire functions and of holomorphic functions in the unit disk. Necessary and sufficient conditions for the existence of universal functions with respect to a sequence of such operators are...

In this paper, it is proved that, for any domain G of the complex plane, there exist an infinite-dimensional closed linear submanifold M1 and a dense linear submanifold M2 with maximal algebraic dimension in the space H(G) of holomorphic functions on G such that G is the domain of holomorphy of every nonzero member of f of M1 or M2 and, in...

In this note, we show that every infinite-dimensional separable Fr´echet space admitting a continuous norm supports an operator for which there is an infinite-dimensional closed subspace consisting, except for zero, of hypercyclic vectors. The family of such operators is even dense in the space of bounded operators when endowed with the strong...