Length Uncertainty in a Gravity's Rainbow Formalism

It is commonly accepted that the combination of quantum mechanics and general relativity gives rise to the emergence of a minimum uncertainty both in space and time. The arguments that support this conclusion are mainly based on perturbative approaches to the quantization, in which the gravitational interactions of the matter content are described as corrections to a classical background. In a recent paper, we analyzed the existence of a minimum time uncertainty in the framework of doubly special relativity. In this framework, the standard definition of the energy-momentum of particles is modified appealing to possible quantum gravitational effects, which are not necessarily perturbative. Demanding that this modification be completed into a canonical transformation determines the implementation of doubly special relativity in position space and leads to spacetime coordinates that depend on the energy-momentum of the particle. In the present work, we extend our analysis to the quantum length uncertainty. We show that, in generic cases, there actually exists a limit in the spatial resolution, both when the quantum evolution is described in terms of the auxiliary time corresponding to the Minkowski background or in terms of the physical time. These two kinds of evolutions can be understood as corresponding to perturbative and non-perturbative descriptions, respectively. This result contrasts with that found for the time uncertainty, which can be made to vanish in all models with unbounded physical energy if one adheres to a non-perturbative quantization.Comment: 12 pages, accepted for publication in Physical Review

Quantum Time Uncertainty in a Gravity's Rainbow Formalism

The existence of a minimum time uncertainty is usually argued to be a consequence of the combination of quantum mechanics and general relativity. Most of the studies that point to this result are nonetheless based on perturbative quantization approaches, in which the effect of matter on the geometry is regarded as a correction to a classical background. In this paper, we consider rainbow spacetimes constructed from doubly special relativity by using a modification of the proposals of Magueijo and Smolin. In these models, gravitational effects are incorporated (at least to a certain extent) in the definition of the energy-momentum of particles without adhering to a perturbative treatment of the back reaction. In this context, we derive and compare the expressions of the time uncertainty in quantizations that use as evolution parameter either the background or the rainbow time coordinates. These two possibilities can be regarded as corresponding to perturbative and non-perturbative quantization schemes, respectively. We show that, while a non-vanishing time uncertainty is generically unavoidable in a perturbative framework, an infinite time resolution can in fact be achieved in a non-perturbative quantization for the whole family of doubly special relativity theories with unbounded physical energy.Comment: 8 pages, accepted for publication in Physical Review

Entropy, fidelity, and double orthogonality for resonance states in two-electron quantum dots

Resonance states of a two-electron quantum dot are studied using a variational expansion with both real basis-set functions and complex scaling methods. The two-electron entanglement (linear entropy) is calculated as a function of the electron repulsion at both sides of the critical value, where the ground (bound) state becomes a resonance (unbound) state. The linear entropy and fidelity and double orthogonality functions are compared as methods for the determination of the real part of the energy of a resonance. The complex linear entropy of a resonance state is introduced using complex scaling formalism

Tool Supported Error Detection and Explanations on Feature Models

Automated analysis of feature models (FM) is a field of interest in recent years. Many operations over FMs have been proposed and developed, and many researchers and industrial companies have adopted FMs as a way to express variability. This last makes more necessary having support to detect, explain and fix errors on FMs. The notation of FMs makes very easy to express variability, but makes hard detecting errors and find their cause manually. and these errors may cause the model does not express the variability what we want of it. Therefore, we need support to detect errors and find their causes. The contribution of this paper is a method to detect errors in FMs, based on the concept of observation. We also present implementations of this approach and of an approach to explain errors, in FaMa Framework [1] tool. To detect FM errors, firstly we have to identify the different error types and what it means each of them. Void FM error means that the FM does not represent any product, dead feature error means that a feature of the FM does not appear in any product, false optional error means that an optional feature appears in every product that its parent feature also appears, and wrong cardinality error means that one or more values of a set relationship cardinality are not reachable. We can check for these errors in a intuitive way. For instance, to detect if a FM has dead features, we can calculate every product and check if each feature appears in, at least, one product. But further, we propose a method based on observations, it means, FM configurations associated with a specific element (feature or cardinality). Each type of error has its type of observation associated too. With an algorithm, we calculate the set of observations of a FM. Then, for each observation, we check if FM has at least one product. If not, we have found an error. For instance, dead feature observation sets its feature as selected. If the FM with a dead feature observation is not valid, it means the feature we are checking is dead. When we have found the errors, explanations tell us what is the cause of each error. An explanation is a set of relationships that originates one or more errors. Changing or removing these relationships we can fix a error. However, explanations by themselves do not provide information about how to change the relationship. For instance, if an explanation about a dead feature is a mandatory relationship, we can turn it into a optional relationship, but the explanation does not tell us directly. We have implemented observations and explanations approaches in FaMa Framework, a tool for the automated analysis of FMs. The observations approach implemented is the previously mentioned, while the explanations approach implemented is the one described by Trinidad et al. [3] [4]. With these approaches, we have detected errors in SPLOT FM repository [2], and we have obtained explanations for them also

Mechanical Isolation of Highly Stable Antimonene under Ambient Conditions

Using mechanical exfoliation combined with a controlled double step transfer procedure we demonstrate that single layers of antimony can be readily produced. These flakes are not significantly contaminated upon exposure to ambient conditions and they do not react with water. DFT calculations confirm our experimental observations and predict a band gap of 1.2-1.3 eV (ambient conditions) for single layer antimonene, which is smaller than that calculated under vacuum conditions at 0 K. Our work confirms antimonene as a highly stable 2D material with promising relevant applications in optoelectronics.Comment: main paper: 5 pages, 4 figures supporting: 9 pages, 7 figures, Advanced Materials, 201

Granitoides peraluminosos con andalucita y cordierita magmáticas en la sierra de Velasco: implicancias para el orógeno famatiniano.

La combinación de estudios petrológicos, geoquímicos y de química mineral en el sector noreste de la sierra de Velasco, a la latitud de la localidad de Santa Vera Cruz, revelan la presencia de una unidad ígnea peraluminosa con andalucita (Si = 3,85, Al = 8,14 y Fe3+ = 0,04) y cordierita (K+Na = 0,33 y XFe = 0,40) magmáticas, la cual es denominada unidad Santa Cruz. La aluminosisad del magma (ISA = 1,30 - 1,42), evidenciada por la presencia de minerales aluminosos como cordierita, andalucita y muscovita y la geoquímica de roca total indican que esta unidad fue derivada de fusión parcial de una secuencia metasedimentaria (esencialmente pelítica) en la corteza superior, que se emplazó en un rango de presión - temperatura de 2 a 2,4 kbar y 670 a 720 ºC. Notablemente, las características geoquímicas de la unidad Santa Cruz sugieren una roca fuente diferente a la establecida para otras unidades peraluminosas del orógeno famatiniano. [ABSTRACT] Peraluminous granitoids with magmatic andalusite and cordierite in the Sierra de Velasco: Implications to the Famatinian Orogen. The combination of petrological, geochemical and mineral/chemical data for the NE sector of the Sierra de Velasco, at the latitud of the Santa Vera Cruz town, reveal the presence of peraluminous igneous unit with magmatic andalusite and cordierite, which has been named Santa Cruz unit. The aluminous of magma (ASI = 1.30 - 1.42), evident by the presence of aluminous minerals such as cordierite, andalusite and muscovite and the whole-rock geochemical, principally indicate that this unit was derived of the partial melting of a metasedimentary secuency (mainly pelitic) in the upper crustal, which was emplaced a pression - temperature range of 2 to 2.4 kb and 670 to 720 ºC. Remarkably, the geochemical characteristics of Santa Cruz unit suggest a different source rock than other peraluminous units founded in the Famatinian Orogen

Активація м’язів плечового пояса та плеча людини в перебігу двосуглобових рухів руки, що виконуються при дії зовнішніх навантажень протилежних напрямів

У дослідах на чотирьох добровольцях досліджувалася координація центральних рухових команд (ЦРК), що керували повільними двосуглобовими рухами руки в горизонтальній площині. Як кореляти інтенсивності таких команд розглядались поточні амплітуди ЕМГ, відведених від шести м’язів плечового пояса і плеча й підданих повному випрямленню та низькочастотній фільтрації. Зокрема, досліджували залежність координації ЦРК від напрямку зовнішньої сили, яка прикладалася до дистальної частини передпліччя. Як виявилося, координація ЦРК істотно залежить від напрямку сили, що згинає ліктьовий суглоб. Згідно з результатами дослідження, ЕМГ певних м’язів у разі виконання двосуглобового руху може бути представлена як лінійна комбінація ЕМГ, зареєстрованих у перебігу послідовних односуглобових рухів в умовах пересування референтної точки кисті в ту ж саму точку операційного простору, що й при двосуглобовому русі. Отримані дані можуть вважатися підтвердженням принципу суперпозиції елементарних ЦРК під час виконання складних рухів кінцівок

Actas del congreso virtual: Avances en tecnologías, innovación y desafío de la educación superior ATIDES 2016.

ls entorns virtuals (educació a distància, e-Learning, blended Learning, laboratoris virtuals...), la globalització universitària (mobilitat virtual, educació global i multicultural, convenis interuniversitaris), cursos a distància massius i oberts (Massive Open Online Courses, MOOC), noves tecnologies en educació, l'espai europeu d'educació superior i els programes de mobilitat a partir de la Declaració de Bolonya, les experiències innovadores en educació, l'evaluació de competències i planificació de ECTS, l'acreditació de la qualitat, els aspectes legals i econòmics de l'educació, la regulació jurídica del dret a l'educació, l'educació i gènere... són alguns dels desafiaments que tracta la publicació

The A-Type event in the eastern Sierras Pampeanas, La Rioja and Catamarca Provinces (Argentina): geochronological and isotopic considerations

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEsubmitte