U-operators

Inspired by a statement of W. Luh asserting the existence of entire functions having together with all their derivatives and antiderivatives some kind of additive universality or multiplicative universality on certain compact subsets of the complex plane or of, respectively, the punctured complex plane, we introduce in this paper the new concept of U-operators, which are defined on the space of entire functions. Concrete examples, including differential and antidifferential operators, composition, multiplication and shift operators, are studied. A result due to Luh, Martirosian and Müller about the existence of universal entire functions with gap power series is also strengthened.Plan Andaluz de Investigación (Junta de Andalucía

Sequences of differential operators: exponentials, hypercyclicity and equicontinuity

In this paper, an eigenvalue criterion for hypercyclicity due to the first author is improved. As a consequence, some new sufficient conditions for a sequence of infinite order linear differential operators to be hypercyclic on the space of holomorphic functions on certain domains of C N are shown. Moreover, several necessary conditions are furnished. The equicontinuity of a family of operators as before is also studied, and it is even characterized if the domain is C N. The results obtained extend or improve earlier work of several authors.Dirección General de Enseñanza Superior (DGES). EspañaJunta de Andalucí

Los frutos de la vanguardia histórica

Cursos, Congresos e Simposios; n. 1

Towards Accurate Modeling of Line-Intensity Mapping One-Point Statistics: Including Extended Profiles

Line-intensity mapping (LIM) is quickly attracting attention as an alternative technique to probe large-scale structure and galaxy formation and evolution at high redshift. LIM one-point statistics are motivated because they provide access to the highly non-Gaussian information present in line-intensity maps and contribute to break degeneracies between cosmology and astrophysics. Now that promising surveys are underway, an accurate model for the LIM probability distribution function (PDF) is necessary to employ one-point statistics. We consider the impact of extended emission and limited experimental resolution in the LIM PDF for the first time. We find that these effects result in a lower and broader peak at low intensities and a lower tail towards high intensities. Focusing on the distribution of intensities in the observed map, we perform the first model validation of LIM one-point statistics with simulations and find good qualitative agreement. We also discuss the impact on the covariance, and demonstrate that if not accounted for, large biases in the astrophysical parameters can be expected in parameter inference. These effects are also relevant for any summary statistic estimated from the LIM PDF, and must be implemented to avoid biased results. The comparison with simulations shows, however, that there are still deviations, mostly related with the modeling of the clustering of emitters, which encourage further development of the modeling of LIM one-point statistics.Comment: 13 pages (+3 pages of references), 7 figure

Cosmological implications of Primordial Black Holes

The possibility that a relevant fraction of the dark matter might be comprised of Primordial Black Holes (PBHs) has been seriously reconsidered after LIGO's detection of a $\sim 30 M_{\odot}$ binary black holes merger. Despite the strong interest in the model, there is a lack of studies on possible cosmological implications and effects on cosmological parameters inference. We investigate correlations with the other standard cosmological parameters using cosmic microwave background observations, finding significant degeneracies, especially with the tilt of the primordial power spectrum and the sound horizon at radiation drag. However, these degeneracies can be greatly reduced with the inclusion of small scale polarization data. We also explore if PBHs as dark matter in simple extensions of the standard $\Lambda$CDM cosmological model induces extra degeneracies, especially between the additional parameters and the PBH's ones. Finally, we present cosmic microwave background constraints on the fraction of dark matter in PBHs, not only for monochromatic PBH mass distributions but also for popular extended mass distributions. Our results show that extended mass distribution's constraints are tighter, but also that a considerable amount of constraining power comes from the high-$\ell$ polarization data. Moreover, we constrain the shape of such mass distributions in terms of the correspondent constraints on the PBH mass fraction.Comment: 20 pages, 9 figures. Matches version accepted to publish in JCA

Francisco Valdés: el viaje inacabado de un escritor de vanguardia

Este autor extremeño, tras su asombrosa puesta al día con la literatura de su época, ejerciendo una crítica ensayística de primerísima línea y cultivando una prosa de raigambre novecentista, pero con nítidas aproximaciones a la mejor prosa poética del 27, desemboca, arrastrado por la "parecida situación político-económica del país a partir de la Segunda República, en una posición reaccionaria, heredera, no obstante, de su humanitario y sensible talante intelectual.This author, after his amazing start up with the literature of his time, putting in the first line his critical essays and cultivating a novecentista prose, but with clear approaches to the best poetic prose of Generation of '27, flows, driven by the similar political and economic situation since the Second Republic, in a reactionary position, heiress, however, of its humanitarian and sensitive intellectual mood.notPeerReviewe

La forma epistolar y sus funciones en "La estafeta romántica" de Galdós

El empleo de la forma epistolar pocos años después de la conquista narrativa llevada a cabo en obras como "La incógnita" y "Realidad", en un episodio nacional de la tercera serie, y en el momento en que se da la dedicación decidida de Galdós, al género teatral, es razón suficiente para calibrar con detenimiento su importancia y no sólo en virtud de la evolución del estilo de su autor y el empleo de determinados recursos narrativos. “La estafeta romántica” es una acertada simbiosis de dos de las corrientes más influyentes en toda la obra de Galdós: la novela histórica y el folletín. El ser un episodio nacional nos evita cualquier explicación sobre los componentes históricos; en cuanto al folletín, toda la serie y específicamente La estafeta da buena cuenta de él.The employment of the epistolary form a few years after the narrative conquest carried out in previous works, in a National Episode, and at the same time that gives the firm commitment of Galdós’ theatrical genre, it's sufficient reason to carefully calibrate its importance and not only in virtue of the evolution of the author’s style and the employment of certain narrative resources. "The romantic Estafeta" is a successful symbiosis of two of the most influential currents in Galdos's entire work: the historical novel and the humorous

La revista "Ultra" de Oviedo en el mar revuelto del ultra

Ultra de Oviedo es una interesante y desconocida revista literaria. Debido a su rareza bibliográfica apenas ha tenido referencias críticas y las pocas, no son muy exhaustivas. Tal vez jugó un papel crucial entre las experiencias regionalistas de la España de vanguardia en el primer período de posguerra y llegó a ser bastión periférico del “Ultraísmo” que brotó en Sevilla y se desarrolló más tarde en Madrid. La revista canalizó los trabajos de vanguardia de sus creadores y también incluye entre sus páginas algunos de los más relevantes poetas de la nueva generación literaria ligada al ultraísmo con nombres como Isaac de Vando Villar, Adriano del Valle, Guillermo de Torre y Gerardo Diego.Ultra from Oviedo is an interesting, almost unknown, literary magazine. Due to its bibliographical rarity it has hardly had critical references, and the very few are not very exhaustive. However, it played a crucial role within the regionalist experiences of the Spanish vanguard in the early years of the postwar period. It became a committed peripheral bastion of the «Ultraísmo», which sprang up in Sevilla and later developed in Madrid. Ultra from Oviedo not only channeled the supposedly vanguard works of its creators, not very well known in national literary panorama, but it also included in its pages some of the most relevant poets of the new literary generation, who were linked to «Ultraísmo». Names such as Isaac de Vando Villar, Adriano del Valle, Guillermo de Torre and Gerardo Diego were among them.notPeerReviewe