Analog quantum simulation of gravitational waves in a Bose-Einstein condensate

We show how to vary the physical properties of a Bose-Einstein condensate (BEC) in order to mimic an effective gravitational-wave spacetime. In particular, we focus in the simulation of the recently discovered creation of particles by real spacetime distortion in box-type traps. We show that, by modulating the speed of sound in the BEC, the phonons experience the effects of a simulated spacetime ripple with experimentally amenable parameters. These results will inform the experimental programme of gravitational wave astronomy with cold atoms.Comment: 9 pages. I. F. previously published as I. Fuentes-Guridi and I.Fuentes-Schuller. v2: minor changes, references adde

Prospective Lifetables: Life Insurance Pricing and Hedging in a Stochastic Mortality Environment

In life insurance, actuaries have traditionally calculated premiums and reserves using a deterministic mortality intensity, which is a function of the age of the insured only. Over the course of the 20th century, the population of the industrialized world underwent a major mortality transition, with a dramatic decline in mortality rates. The mortality decline has been dominated by two major trends: a reduction in mortality due to infectious diseases affecting mainly young ages, and a decrease in mortality at old ages. These mortality improvements have to be taken into account to price long-term life insurance products and to analyse the sustainability of social security systems. In this paper, we argue that pricing and reserving for pension and life insurance products requires dynamic (or prospective) lifetables. We briefly review classic and recent projection methods and adopt a Poisson log-bilinear approach to estimate Portuguese Prospective Lifetables. The advantages of using dynamic lifetables are twofold. Firstly, it provides more realistic premiums and reserves, and secondly, it quantifies the risk of the insurance companies associated with the underlying longevity risks. Finally, we discuss possible ways of transferring the systematic mortality risk to other parties.

Geometric Objects: A Quality Index to Electromagnetic Energy Transfer Performance in Sustainable Smart Buildings

Sustainable smart buildings play an essential role in terms of more efficient energy. However, these buildings as electric loads are affected by an important distortion in the current and voltage waveforms caused by the increasing proliferation of nonlinear electronic devices. Overall, buildings all around the world consume a significant amount of energy, which is about one-third of the total primary energy resources. Optimization of the power transfer process of such amount of energy is a crucial issue that needs specific tools to integrate energy-efficient behaviour throughout the grid. When nonlinear loads are present, new capable ways of thinking are needed to consider the effects of harmonics and related power components. In this manner, technology innovations are necessary to update the power factor concept to a generalized total or a true one, where different power components involved in it calculation, properly reflect each harmonic interaction. This work addresses an innovative theory that applies the Poynting Vector philosophy via Geometric Algebra to the electromagnetic energy transfer process providing a physical foundation. In this framework, it is possible to analyse and detect the nature of disturbing loads in the exponential growth of new globalized buildings and architectures in our era. This new insight is based on the concept of geometric objects with different dimension: vector, bivector, trivector, multivector. Within this paper, these objects are correlated with the electromagnetic quantities responsible for the energy flow supplied to the most common loads in sustainable smart buildings. Besides, it must be considered that these phenomena are characterized by a quality index multivector appropriate even for detecting harmonic sources. A numerical example is used to illustrate the clear capabilities of the suggested index when it applies to industrial loads for optimization of energy control systems and enhance comfort management in smart sustainable buildings

Continuous harmonic analysis and power quality measurements in three-phase systems

A virtual instrument, named Power Quality Meter, is presented for (a) measuring power consumption and harmonics in three-phase systems, under non-sinusoidal and imbalance conditions (b) detecting, classifying and organizes power disturbance events. Measurement of the power consumption follows the formulation proposed by the members of the IEEE Working Group on Nonsinusoidal Situations (1996). So, definitions are based on the analysis of functions in the frequency domain, separating the fundamental terms from the harmonic terms of the Fourier series. The virtual instrument has been developed too for monitoring and measuring power disturbances, which are automatically classified and organized in a database while they are being recorded. Software tools use the database structure to present summaries of power disturbances and locate an event by severity or time of occurrence. Records of actual measurements are included to demonstrate the versatility of the instrument

Quantum Singular Value Decomposer

We present a variational quantum circuit that produces the Singular Value Decomposition of a bipartite pure state. The proposed circuit, that we name Quantum Singular Value Decomposer or QSVD, is made of two unitaries respectively acting on each part of the system. The key idea of the algorithm is to train this circuit so that the final state displays exact output coincidence from both subsystems for every measurement in the computational basis. Such circuit preserves entanglement between the parties and acts as a diagonalizer that delivers the eigenvalues of the Schmidt decomposition. Our algorithm only requires measurements in one single setting, in striking contrast to the $3^n$ settings required by state tomography. Furthermore, the adjoints of the unitaries making the circuit are used to create the eigenvectors of the decomposition up to a global phase. Some further applications of QSVD are readily obtained. The proposed QSVD circuit allows to construct a SWAP between the two parties of the system without the need of any quantum gate communicating them. We also show that a circuit made with QSVD and CNOTs acts as an encoder of information of the original state onto one of its parties. This idea can be reversed and used to create random states with a precise entanglement structure.Comment: 6 + 1 pages, 5 figure

Consideraciones sobre el concepto de ley natural en San Pablo

El concepto de ley natural reflejado en los dos primeros capftulos de la Carta de San Pablo a los Romanos, significa, en la historia de la Filosoffajurfdica, el nacimiento de un nuevo lusnaturalismo, que con rafces en el pensamiento cliisico grecorromano, se fundamenta en la nueva dimension antropologica que proporciona el Cristianismo. A partir del posicionarniento crftico del Apostol ante la ley mosaica, se analiza esa idea de una ley no escrita que fluye de la naturaleza humana, estii presente en los corazones de todos los hombres, y acrua al servicio de la gracia y la verdadera justicia, representada por el Evangelio. Una ley natural que constituye ademiis prueba inequfvoca de la existencia de una etica y de una teologfa naturales basadas en la razon.In the history of Legal Philosophy, natural law concept, reflected in both two first chapters of the Letter of San Pablo to the Romans, means the birth of a new Iusnaturalism. This concept takes roots in the greco-roman classic thought and is based on the new anthropological dimension that provides Christianity. From the Apostle critical view regarding the mosaic law, we can analyse the idea of a nonwritten law that flows from human nature. This law is born in men's heart and works for grace and true justice, represented by Gospel. In addition this natural law constitutes an unequivocal test of the existence of a natural ethics and a theology based on reason

Reflection and transmission of matter waves in two-component Bose-Einstein condensates

En col·laboració amb la Universitat Autònoma de Barcelona (UAB), la Universitat de Barcelona (UB) i l’Institut de Ciències Fotòniques (ICFO)We investigate the dynamical properties of 1D solitary waves in confined immiscible mixtures of Bose-Einstein condensates with repulsive interparticle interactions. We perform numerical simulations of the coupled Gross-Pitaevskii equations for two-components harmonically trapped in presence of dark and grey solitons, and we study the reflection and transmission of this matter wave after the collision with the interphase between the two immiscible species. Our numerical results show different scenarios depending on the ratio between the interspecies and intraspecies strength interactions, where the immiscibility plays an important role in the dynamical behaviour of the matter wave