On the accretion of phantom energy onto wormholes

By using a properly generalized accretion formalism it is argued that the accretion of phantom energy onto a wormhole does not make the size of the wormhole throat to comovingly scale with the scale factor of the universe, but instead induces an increase of that size so big that the wormhole can engulf the universe itself before it reaches the big rip singularity, at least relative to an asymptotic observer.Comment: 4 pages, LaTex, to appear in Phys. Lett.

The entangled accelerating universe

Using the known result that the nucleation of baby universes in correlated pairs is equivalent to spacetime squeezing, we show in this letter that there exists a T-duality symmetry between two-dimensional warp drives, which are physically expressible as localized de Sitter little universes, and two dimensional Tolman-Hawking and Gidding-Strominger baby universes respectively correlated in pairs, so that the creation of warp drives is also equivalent to spacetime squeezing. Perhaps more importantly, it has been also seen that the nucleation of warp drives entails a violation of the Bell's inequalities, and hence the phenomena of quantum entanglement, complementarity and wave function collapse. These results are generalized to the case of any dynamically accelerating universe filled with dark or phantom energy whose creation is also physically equivalent to spacetime squeezing and to the violation of the Bell's inequalities, so that the universe we are living in should be governed by essential sharp quantum theory laws and must be a quantum entangled system

Order regularity for Birkhoff interpolation with lacunary polynomials

In this short paper we present sufficient conditions for the order regularity problem in Birkhoff interpolation with lacunary polynomials. These conditions are a generalization of the Atkinson-Sharma theorem.Peer ReviewedPostprint (published version

Gelation of n3p3[nh(ch2)3si(oet)3]6-n [x]n x = nh(ch2)3si(oet)3, nch3(ch2)3cn and oc6h4(ch2)cn, n = 0 or 3 at the liquid/air/interface

Indexación: ScieloThe compounds N3P3[NH(CH2)3Si(OEt)3]6 (1), N3P3[NH(CH2)3Si(OEt)3]3[NCH3(CH2)3CN]3 (2) and N3P3[NH(CH2)3Si(OEt)3]3 [HOC6H4(CH2)CN]3 (3) undergo slow gelation at the interface oil/air at low temperatures to give perfect gels G1, G2 and G3 respective ly. TEM analysis reveals nanoparticles of silica with mean size of about 10 nm. Pyrolysis under air at 800 °C of these gels affords a mixture of mainly Si5(PO4)6O, SiP2O7 and SiO2. Gelation and pyrolysis products were characterized by IR, solid-state NMR, TEM, SEM-EDAX microscopy and X-ray diffraction. The sol-gel process in the interface liquid /air is discussed in comparison with the usual sol-gel solution process.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072010000300031&nrm=is

Oligarquía y fiscalidad: los primeros pasos de la contribución de inmuebles, cultivo y ganadería en la provincia de Alicante

Editada en la Fundación Empresa PúblicaEl objetivo del artículo es analizar la andadura de la contribución territorial en la provincia de Alicante durante la Década Moderada (1844-1854). Además del análisis de la estructura de la contribución territorial -el cupo y sus recargos—, se estudia también el reparto del impuesto entre los pueblos de la provincia, así como el reparto individual entre los contribuyentes de la ciudad de Alicante y su comarca. Una mejor comprensión de las implicaciones sociales y políticas de la nueva figura tributaria hace también necesaria la referencia a las protestas de pueblos y particulares ante los repartos efectuados por las oligarquías provinciales y locales, protestas que evidencian tanto la injusticia que presidió esos repartos, como las resistencias que provocó el impuesto, y que se tradujeron en un alto nivel de fraude.This article aims to analyze the territorial taxes in the province of Alicante during the Década Moderada (1844-1854). Besides a structural analysis of the territorial taxes —quota and its charges—, the sharing out of taxes among the villages of the province, as well as the individual share of taxpayers in the town of Alicante and its province will be studied. Reference to the objections from villages and individuals to the sharing out effected by the provincial and local oligarchy is therefore necessary in order to understand the political and social implications of the new tax. Such objections show the extent to which the sharing out was unfair and the resistance offered towards the taxes, which resulted in high levels of tax evasion.Publicad

Computing the Component-Labeling and the Adjacency Tree of a Binary Digital Image in Near Logarithmic-Time

Connected component labeling (CCL) of binary images is one of the fundamental operations in real time applications. The adjacency tree (AdjT) of the connected components offers a region-based representation where each node represents a region which is surrounded by another region of the opposite color. In this paper, a fully parallel algorithm for computing the CCL and AdjT of a binary digital image is described and implemented, without the need of using any geometric information. The time complexity order for an image of m × n pixels under the assumption that a processing element exists for each pixel is near O(log(m+ n)). Results for a multicore processor show a very good scalability until the so-called memory bandwidth bottleneck is reached. The inherent parallelism of our approach points to the direction that even better results will be obtained in other less classical computing architectures.Ministerio de Economía y Competitividad MTM2016-81030-PMinisterio de Economía y Competitividad TEC2012-37868-C04-0

Modulation instability-induced fading in phase-sensitive optical time-domain reflectometry

Phase-sensitive optical time-domain reflectometry (?OTDR) is a simple and effective tool allowing the distributed monitoring of vibrations along single-mode fibers. We show in this Letter that modulation instability (MI) can induce a position-dependent signal fading in long-range ?OTDR over conventional optical fibers. This fading leads to a complete masking of the interference signal recorded at certain positions and therefore to a sensitivity loss at these positions. We illustrate this effect both theoretically and experimentally. While this effect is detrimental in the context of distributed vibration analysis using ?OTDR, we also believe that the technique provides a clear and insightful way to evidence the Fermi?Pasta?Ulam recurrence associated with the MI process