A two particle hidden sector and the oscillations with photons

We present a detailed study of the oscillations and optical properties for vacuum, in a model for the dark sector that contains axion-like particles and hidden photons. In this model, both can couple to photons. We provide bounds for the couplings versus the mass, using current results from ALPS-I and PVLAS. We also discuss the challenges for the detection of models with more than one hidden particle in light shining trough wall-like experiments.Comment: 23 pages, 7 figures. Figures are coloure

New records and geographic distribution map of Bothropoides diporus Cope, 1862 (Reptilia: Viperidae)

We provide two new records of Bothropoides diporus for Neuquén province, northern Patagonia, Argentina. Both records are the second and third for this species in this province. One of these records, from the northern slope of Auca Mahuida Mountain, extends approximately 120 km to the north the present known geographic distribution of this species in Neuquén province.Fil: Minoli, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Janis Alvarez, Diego. Universidade Federal do Rio Grande do Sul; BrasilFil: Avila, Luciano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

The sovereign minority: the qualified majority rule for constitutional amendments

The paper challenges the widespread intuition according to which the constitutional amendment procedure normatively requires the application of the qualified majority rule as a collective decision rule. To this end, the relationship between majority rule and the qualified majority is clarified and the link between qualified majority and constitutional supremacy is questioned. The institutional role played by the qualified majority rule of the constitutional amendment in parliament is then clarified in order to discredit the widespread justification of the qualified majority based on the notion of precommitment

Funciones de rango de Sylvester, anillos de división épicos y la conjetura fuerte de Atiyah para grupos localmente indicables

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Matemáticas. Fecha de lectura: 04-03-202

On the Influence of Spatial Dispersion on the Performance of Graphene-Based Plasmonic Devices

We investigate the effect of spatial dispersion phenomenon on the performance of graphene-based plasmonic devices at THz. For this purpose, two different components, namely a phase shifter and a low-pass filter, are taken from the literature, implemented in different graphene-based host waveguides, and analyzed as a function of the surrounding media. In the analysis, graphene conductivity is modeled first using the Kubo formalism and then employing a full-$k_\rho$ model which accurately takes into account spatial dispersion. Our study demonstrates that spatial dispersion up-shifts the frequency response of the devices, limits their maximum tunable range, and degrades their frequency response. Importantly, the influence of this phenomenon significantly increases with higher permittivity values of the surrounding media, which is related to the large impact of spatial dispersion in very slow waves. These results confirm the necessity of accurately assessing non-local effects in the development of practical plasmonic THz devices.Comment: 5 pages, 18 figures, 2 table