The Applegate mechanism in Post-Common-Envelope Binaries: Investigating the role of rotation

Eclipsing time variations (ETVs) are observed in many close binary systems. In particular, for several post-common-envelope binaries (PCEBs) that consist of a white dwarf and a main sequence star, the O-C diagram suggests that real or apparent orbital period variations are driven by Jupiter-mass planets or as a result of magnetic activity, the so-called Applegate mechanism. The latter explains orbital period variations as a result of changes in the stellar quadrupole moment due to magnetic activity. We explore the feasibility of driving ETVs via the Applegate mechanism for a sample of PCEB systems, including a range of different rotations. Using the MESA code we evolve 12 stars with different masses and rotation rates. We apply a simple dynamo model to their radial profiles to investigate on which scale the predicted activity cycle matches the observed modulation period, and quantify the uncertainty, and further calculate the required energies to drive que Applegate mechanism. We show that the Applegate mechanism is energetically feasible in 5 PCEB systems, and note that these are the systems with the highest rotation rate compared to the critical rotation rate of the main-sequence star. The results suggest that the ratio of physical to critical rotation in the main sequence star is an important indicator for the feasibility of Applegate's mechanism, but exploring larger samples will be necessary to probe this hypothesis.Comment: 9 pages, 5 figures. Accepted for publication in A&

Bulge RR Lyrae stars in the VVV tile b201\textit{b201}

The VISTA Variables in the V\'ia L\'actea (VVV) Survey is one of the six ESO public surveys currently ongoing at the VISTA telescope on Cerro Paranal, Chile. VVV uses near-IR ($ZYJHK_{\rm s}$) filters that at present provide photometry to a depth of $K_{\rm s} \sim 17.0$ mag in up to 36 epochs spanning over four years, and aim at discovering more than 10$^6$ variable sources as well as trace the structure of the Galactic bulge and part of the southern disk. A variability search was performed to find RR Lyrae variable stars. The low stellar density of the VVV tile $\textit{b201}$, which is centered at ($\ell, b$) $\sim$ ($-9^\circ, -9^\circ$), makes it suitable to search for variable stars. Previous studies have identified some RR Lyrae stars using optical bands that served to test our search procedure. The main goal is to measure the reddening, interstellar extinction, and distances of the RR Lyrae stars and to study their distribution on the Milky Way bulge. A total of 1.5 sq deg were analyzed, and we found 39 RR Lyrae stars, 27 of which belong to the ab-type and 12 to the c-type. Our analysis recovers all the previously identified RR Lyrae variables in the field and discovers 29 new RR Lyrae stars. The reddening and extinction toward all the RRab stars in this tile were derived, and distance estimations were obtained through the period--luminosity relation. Despite the limited amount of RR Lyrae stars studied, our results are consistent with a spheroidal or central distribution around $\sim 8.1$ and $\sim 8.5$ kpc. for either the Cardelli or Nishiyama extinction law.Comment: 10 pages, 8 figures, accepted for publication in Astronomy and Astrophysic

Disidencias y discordancias en la obra del escritor argentino Andrés Rivera

Antes de ser periodista y luego escritor, Andrés Rivera fue obrero textil y miembro del partido comunista argentino. Sus primeros relatos (publicados entre 1957 y 1965) están ambientados en las fábricas textiles y sus protagonistas son militantes sindicalistas. Después del proceso militar —durante el cual Rivera no pudo publicar— su obra fue marcada por cambios no solamente estéticos sino también temáticos, al tratar de la historia de su familia o de la Historia argentina. El denominador común de dichas obras es la disidencia que caracteriza a sus protagonistas, ficticios a diferentes grados ya que unos son los dobles del autor mismo y de su padre (como Arturo y Mauricio Reedson) y otros son figuras de la Historia argentina como Juan José Castelli, Juan Manuel de Rosas, o el General Paz. Proponemos estudiar primero a estos disidentes, narradores autodiegéticos de su propia historia marcada por la derrota. En una segunda parte analizaremos cómo estas voces disidentes y discordantes se manifiestan en la escritura de Rivera. En efecto, la duda, propia de los vencidos para Rivera, resalta a través de la memoria a veces borrosa de protagonistas viejos, enfermos o delirantes, quienes se preguntan cómo no pudieron hacer escuchar su voz. La historia personal de cada uno se superpone a la Historia, y la subjetividad del relato expone en una fragmentación tanto discursiva como cronotópica diferentes versiones de la Historia, problematizando su escritura misma

Analysis of the Topology for Moving Wireless Networks

This document presents an analysis of the factors that influence the network topology in a broadband mobile wireless as hoc networks moving on platforms. This paper focuses on studying the topology for networks where the nodes carrying the access points are constantly moving within urban areas. The influence of the number of nodes as well as the structure of the streets (type of mobility) on the network topology is also studied. To do that, this paper will first present methods to analyze the influence of the velocity of the nodes on the network topology. Second, the implications of number of nodes and type of mobility combination are also analyzed. When there are more nodes in a certain type of mobility area, it is expected that the topology of the network follow that structure shape

Trabajos de Prehistoria: su trayectoria como revista de impacto internacional

[ES] En 2008 Trabajos de Prehistoria entró en las bases de datos internacionales del SSCI, A&HCI y Scopus siendo la primera revista española del área de Arqueología con factor de impacto JCR. En el trabajo se muestra cómo este proceso de internacionalización es consecuencia de diferentes iniciativas de política científica del estado a nivel nacional y del propio CSIC. Se analiza la trayectoria de la revista desde su creación y se valora el impacto de esta internacionalización en su gestión reciente. Cabe destacar el papel[EN] Trabajos de Prehistoria was included in 2008 in the SSCI, A&HCI and Scopus international scientific databases. It was the first Spanish archaeological journal with a JCR impact factor. This paper shows how several initiatives in scientific policy by the National Spanish Government and the CSIC lead to international recognition. This study also shows the trajectory of the journal since its creation and evaluates the effects of the internationalisation on the current management. The role played by the reviewers has been fundamental in attaining and maintaining the journal’s high scientific quality.Peer reviewe

Spontaneous symmetry breaking as a resource for noncritically squeezed light

In the last years we have proposed the use of the mechanism of spontaneous symmetry breaking with the purpose of generating perfect quadrature squeezing. Here we review previous work dealing with spatial (translational and rotational) symmetries, both on optical parametric oscillators and four-wave mixing cavities, as well as present new results. We then extend the phenomenon to the polarization state of the signal field, hence introducing spontaneous polarization symmetry breaking. Finally we propose a Jaynes-Cummings model in which the phenomenon can be investigated at the single-photon-pair level in a non-dissipative case, with the purpose of understanding it from a most fundamental point of view.Comment: Review for the proceedings of SPIE Photonics Europe. 11 pages, 5 figures

Inducing nonclassical lasing via periodic drivings in circuit quantum electrodynamics

We show how a pair of superconducting qubits coupled to a microwave cavity mode can be used to engineer a single-atom laser that emits light into a nonclassical state. Our scheme relies on the dressing of the qubit-field coupling by periodic modulations of the qubit energy. In the dressed basis, the radiative decay of the first qubit becomes an effective incoherent pumping mechanism that injects energy into the system, hence turning dissipation to our advantage. A second, auxiliary qubit is used to shape the decay within the cavity, in such a way that lasing occurs in a squeezed basis of the cavity mode. We characterize the system both by mean-field theory and exact calculations. Our work may find applications in the generation of squeezing and entanglement in circuit QED, as well as in the study of dissipative few- and many-body phase transitions

Sedimentary heterogeneity and petrophysical characterization of Barremian tsunami and barrier island/inlet deposits: The Aliaga outcrop as a reservoir analogue (Galve sub-basin, eastern Spain)

The present study examined two sandstone deposits in the Aliaga outcrop as a reservoir analogue over a distance of 200-m-long and attempted to establish a correlation between sand facies and the petrophysical properties of the sandstones in order to investigate the reservoir heterogeneity. The Aliaga reservoir analogue represents the upper part of Camarillas Fm., deposited during the Barremian synrift phase of the Galve sub-basin (Iberian Basin, Spain). It is characterized by a transitional sedimentary interval from sandy-dominant deposits to carbonate-dominant deposits, which were deposited under the same palaeoenvironmental conditions (in relation to systems of back-barrier sedimentation). The description of the Aliaga outcrop provided here consists of lithological descriptions of two sandstone deposits: a tsunami and a barrier island/inlet, at both mesoscopic (decimetres to tens of metres) and microscopic scales (millimetres to centimetres). Both deposits recognized at the basin scale were described in terms of sand grain size, sand sorting and cementation; further cores were drilled along outcrop to collect samples for porosity and permeability measurements. Both sandstone reservoirs are the result of different sedimentary processes that determined facies characteristics, as the different petrophysical properties observed in these deposits. Consequently, the sedimentary process controls the heterogeneity of the sandstones facies and thus, the sand heterogeneity controls the distribution of the petrophysical properties. The classification of sand facies in terms of sand sorting seems to be more appropriate for describing sand heterogeneity; accordingly, petrophysical parameters in both deposits were also influenced by sand sorting. The sand facies and petrophysics heterogeneity of the described deposits can be hierarchically ordered. First-order heterogeneity is related to the basin scale, second-order heterogeneity is related to genesis and the conditions of sediment deposition, and third-order heterogeneity is related to synsedimentary faults and/or post-sedimentation events.This research is a contribution to the project: Análisis de Cuencas Sedimentarias Continentales, of the Gobierno de Aragón, the Análisis de Cuencas Sedimentarias Group of the UCM-CAM, and the projects CGL2011-23717 (Ministerio de Ciencia e Innovación of the Spanish Government and FEDER) and UZ2015-CIE-10 (University of Zaragoza). Additional financial support was provided by a Cnpq (Conselho Nacional de Pesquisa e Desenvolvimento Tecnologico, Brasil) Research Grant (200147/2011-0) and an IAS Schema 1st session 2014 Postgraduate Grant to F. Veloso.Peer reviewe