Calculus of variations for integrals depending on a convolution product
The -approximation property and the weak topology in tensor products of Banach spaces
The positive Schur property in Banach lattices.
Absolutely summing operators between Banach spaces of finite cotype.
On the structure of tensor norms related to (p,σ)-absolutely continuous operators.
We define an interpolation norm on tensor products of p-integrable function spaces and Banach spaces which satisfies intermediate properties between the Bochner norm and the injective norm. We obtain substitutes of the Chevet-Persson-Saphar inequalities for this case. We also use the calculus of traced tensor norms in order to obtain a tensor product description of the tensor norm associated to the interpolated ideal of (p, sigma)-absolutely continuous operators defined by Jarchow and Matter. As...
Product spaces generated by bilinear maps and duality
In this paper we analyse a definition of a product of Banach spaces that is naturally associated by duality with a space of operators that can be considered as a generalization of the notion of space of multiplication operators. This dual relation allows to understand several constructions coming from different fields of functional analysis that can be seen as instances of the abstract one when a particular product is considered. Some relevant examples and applications are shown, regarding pointwise...
Predicción del IPC utilizando métodos de subespacio.
Lattice copies of c₀ and in spaces of integrable functions for a vector measure
The spaces L¹(m) of all m-integrable (resp. of all scalarly m-integrable) functions for a vector measure m, taking values in a complex locally convex Hausdorff space X (briefly, lcHs), are themselves lcHs for the mean convergence topology. Additionally, is always a complex vector lattice; this is not necessarily so for L¹(m). To identify precisely when L¹(m) is also a complex vector lattice is one of our central aims. Whenever X is sequentially complete, then this is the case. If, additionally,...
Solving a class of generalized Lyapunov operator differential equations without the exponential operator function.
In this paper a method for solving operator differential equations of the type X' = A + BX + XD; X(0) = C, avoiding the operator exponential function, is given. Results are applied to solve initial value problems related to Riccati type operator differential equations whose associated algebraic equation is solvable.
An algebraic approach for solving boundary value matrix problems: existence, uniqueness and closed form solutions.
In this paper we show that in an analogous way to the scalar case, the general solution of a non homogeneous second order matrix differential equation may be expressed in terms of the exponential functions of certain matrices related to the corresponding characteristic algebraic matrix equation. We introduce the concept of co-solution of an algebraic equation of the type X^2 + A1.X + A0 = 0, that allows us to obtain a method of the variation of the parameters for the matrix case and further to find...
A new metrization theorem
We give a new metrization theorem on terms of a new structure introduced by the authors in [2] and called fractal structure. As a Corollary we obtain Nagata-Smirnovs and Uryshons metrization Theorems.
Ideales de operadores absolutamente continuos.
The associated tensor norm to -absolutely summing operators on -spaces
We give an explicit description of a tensor norm equivalent on to the associated tensor norm to the ideal of -absolutely summing operators. As a consequence, we describe a tensor norm on the class of Banach spaces which is equivalent to the left projective tensor norm associated to .
On uniformly locally compact quasi-uniform hyperspaces
We characterize those Tychonoff quasi-uniform spaces for which the Hausdorff-Bourbaki quasi-uniformity is uniformly locally compact on the family of nonempty compact subsets of . We deduce, among other results, that the Hausdorff-Bourbaki quasi-uniformity of the locally finite quasi-uniformity of a Tychonoff space is uniformly locally compact on if and only if is paracompact and locally compact. We also introduce the notion of a co-uniformly locally compact quasi-uniform space and show...
Computing complexity distances between algorithms
We introduce a new (extended) quasi-metric on the so-called dual p-complexity space, which is suitable to give a quantitative measure of the improvement in complexity obtained when a complexity function is replaced by a more efficient complexity function on all inputs, and show that this distance function has the advantage of possessing rich topological and quasi-metric properties. In particular, its induced topology is Hausdorff and completely regular. Our approach is applied to the measurement...
Compactness in L¹ of a vector measure
We study compactness and related topological properties in the space L¹(m) of a Banach space valued measure m when the natural topologies associated to convergence of vector valued integrals are considered. The resulting topological spaces are shown to be angelic and the relationship of compactness and equi-integrability is explored. A natural norming subset of the dual unit ball of L¹(m) appears in our discussion and we study when it is a boundary. The (almost) complete continuity of the integration...
Metrizability of the unit ball of the dual of a quasi-normed cone
We obtain theorems of metrization and quasi-metrization for several topologies of weak* type on the unit ball of the dual of any separable quasi-normed cone. This is done with the help of an appropriate version of the Alaoglu theorem which is also obtained here.
Reduced commutative monoids with two Archimedean components
Si studiano i monoidi commutativi ridotti con due componenti archimedee e si forniscono dei teoremi di strutture. Si presta particolare attenzione a quei monoidi che sono finitamente generati, e si danno degli algoritmi che permettono di ottenere informazioni a partire da un delle loro presentazioni.
Semigroup-theoretical characterizations of arithmetical invariants with applications to numerical monoids and Krull monoids
Arithmetical invariants—such as sets of lengths, catenary and tame degrees—describe the non-uniqueness of factorizations in atomic monoids.We study these arithmetical invariants by the monoid of relations and by presentations of the involved monoids. The abstract results will be applied to numerical monoids and to Krull monoids.
Redundancy of genetic information and evolution of living systems
La reiterazione di alcuni geni nelle cellule eucariotiche è qui interpretata come una ridondanza informazionale in senso cibernetico, comparsa nel corso dell'evoluzione in concomitanza con la distinzione tra linea somatica e linea germinale. Questa ridondanza genica tamponerebbe gli effetti fenotipici delle mutazioni somatiche ela sua comparsa sarebbe stata quindi essenziale per l'evoluzione di organismi viventi complessi. Questo punto di vista implica una efficiente rettificazione dei geni ridondanti...
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