Verification of Quantum Stable Sources

We introduce the problem of verification of stable sources in quantum systems. This problem is closely related to the problem of quantum verification first proposed by Pallister et. al. [1], however it extends the notion of the original problem. We introduce a family of states that come from a non-i.i.d. source which we call a Markov state. We prove in theorem 1 that these states are not well described with tensor products over a changing source. In theorem 2 we further provide a lower bound on the trace distance between two Markov states, which is the simplest way to solve the problem of verification of quantum stable sources.Comment: 6 pages, 4 figure

Quantum Stabilizer Channel for Thermalization

We study the problem of quantum thermalization from a very recent perspective: via discrete interactions with thermalized systems. We thus extend the previously introduced scattering thermalization program by studying not only a specific channel but allowing any possible one. We find a channel that solves a fixed point condition using the Choi matrix approach that is in general non-trace-preserving. We also find a general way to complement the found channel so that it becomes trace-preserving. Therefore we find a general way of characterizing a family of channels with the same desired fixed point. From a quantum computing perspective, the results thus obtained can be interpreted as a condition for quantum error correction that also reminds of quantum error avoiding.Comment: 6 pages,1 figur

Classicality from Quantum Stochastic Processes

We develop a theory of classicality from quantum systems. This theory stems from the study of classical and quantum stationary stochastic processes. The stochastic processes are characterized by polyhedral (classical) and semidefinite representative (quantum) cones. Based on a previous result \cite{2209.06806v1} we expand the study of fixed points from quantum channels. We give a semidefinite program that characterizes a quantum channel separating into a core and a part that decays with many iterations. In general, the solution is non-separable in the space it is defined. We present a characterization of channels in terms of their fixed points for the separable case. A quantum simulation of a polyhedral cone can then be constructed.Comment: 12 pages, 1 figur

Sequential Analysis of Chunks of Pure Qubits

We investigate an advantage for information processing of ordering a set of states over making a global quantum measurement with a fixed number of copies. The setting that we want to investigate is clearer if we introduce Alice and Bob, as usual. Suppose Alice has $N<\infty$ copies of one of two quantum states $\sigma_0$ or $\sigma_1$ and she gives this states to Bob. We find that there are situations where Bob has to make chunks of $l$ states and process them sequentially to optimally distinguish the two hypotheses. We find an expression for the optimal $l$ given some desired error constraints in the case of pure qubits. The results presented here also have relevance in the "it from qubit" program in the sense that they suggest that time arises from information processing.Comment: 5 pages, 2 figure

Relativistic time dilation as a quantum mechanism

We propose a mechanism for time dilation using quantum systems. We introduce a family of operators that are sensitive to the changes of quantum states from different frames of reference. The change between reference frames is done via a Galilean transformation, therefore, the source of the dilation in our case comes from the observable. These observables grow linearly in time and depending on the reference frame of the state the linear growth changes its slope, therefore it takes longer to grow to the same point. Such mechanism implies a different view from the usual understanding of spacetime.Comment: 10 pages, 3 figure

Quantum measurement optimization by decomposition of measurements into extremals

Using the convex structure of positive operator value measurements and of several quantities used in quantum metrology, such as quantum Fisher information or the quantum Van Trees information, we present an efficient numerical method to find the best strategy allowed by quantum mechanics to estimate a parameter. This method explores extremal measurements thus providing a significant advantage over previously used methods. We exemplify the method for different cost functions in a qubit and in a harmonic oscillator and find a strong numerical advantage when the desired target error is sufficiently small.Comment: 12 page

Lagrangean Relaxation Parallel Method for Optimizing of a Hydroelectric Generation System

AbstractThis paper presents the Lagrangean Relaxation parallel method applied to the optimal commitment of generating units in a Hydroelectric System. The model is implemented on a cluster built upon low cost readily available personal computers. It also introduces the algorithms applied in the above mentioned platform. The results obtained in terms of “Speed Up” for a sample problem of rather important dimensions, indicate the validity of the proposal

Guía de diseño para portales web transparentes

ManualLa Guía de diseño para portales web transparentes es una herramienta para facilitar el proceso de construcción de las secciones de transparencia a las personas encargadas de actualizar el contenido de los sitios web de las instituciones y organizaciones. El usuario de esta guía no requerirá tener conocimientos previos en comunicación, diseño gráfico, diseño web ni programación para poder comprender e implementar cada uno de los apartados de la guía. Sin embargo, si los posee, encontrará en ella una herramienta para definir la estructura, estilo visual y contenido de transparencia de manera ágil, contando con estándares y buenas prácticas definidas a nivel internacional.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Centro de Investigación y Capacitación en Administración Pública (CICAP