Dynamical phases for the evolution of the entanglement between two oscillators coupled to the same environment

We study the dynamics of the entanglement between two oscillators that are initially prepared in a general two-mode Gaussian state and evolve while coupled to the same environment. In a previous paper we showed that there are three qualitatively different dynamical phases for the entanglement in the long time limit: sudden death, sudden death and revival and no-sudden death [Paz & Roncaglia, Phys. Rev. Lett. 100, 220401 (2008)]. Here we generalize and extend those results along several directions: We analyze the fate of entanglement for an environment with a general spectral density providing a complete characterization of the corresponding phase diagrams for ohmic and sub--ohmic environments (we also analyze the super-ohmic case showing that for such environment the expected behavior is rather different). We also generalize previous studies by considering two different models for the interaction between the system and the environment (first we analyze the case when the coupling is through position and then we examine the case where the coupling is symmetric in position and momentum). Finally, we analyze (both numerically and analytically) the case of non-resonant oscillators. In that case we show that the final entanglement is independent of the initial state and may be non-zero at very low temperatures. We provide a natural interpretation of our results in terms of a simple quantum optics model.Comment: 18 pages, 13 figure

Production system and method for producing fluids from a well

A production system and method for producing fluids from a well are presented. The production system may include a submersible pump and a jet pump. The submersible pump may be arranged within the well. The jet pump may be arranged within the well downstream of the submersible pump. The jet pump may include a power fluid intake configured to receive a power fluid and a produced fluid intake configured to receive a produced fluid. The power fluid intake may be in fluid communication with the submersible pump. The produced fluid intake may be in fluid communication with gas within the well. In an embodiment, the produced fluid intake may be in fluid communication with separated gas within an annulus of the well. Beneficially, the system may allow, among other things, a submersible pump and a jet pump to be used in combination in high gas-liquid-ratio wells without installing a gas vent line.Board of Regents, University of Texas Syste

Production system and method for producing fluids from a well

A production system and method for producing fluids from a well are presented. The production system may include a submersible pump and a jet pump. The submersible pump may be arranged within the well. The jet pump may be arranged within the well downstream of the submersible pump. The jet pump may include a power fluid intake configured to receive a power fluid and a produced fluid intake configured to receive a produced fluid. The power fluid intake may be in fluid communication with the submersible pump. The produced fluid intake may be in fluid communication with gas within the well. In an embodiment, the produced fluid intake may be in fluid communication with separated gas within an annulus of the well. Beneficially, the system may allow, among other things, a submersible pump and a jet pump to be used in combination in high gas-liquid-ratio wells without installing a gas vent line.Board of Regents, University of Texas Syste

Representing Complexity in Part-Whole Relationships within the Foundational Model of Anatomy

The Foundational Model of Anatomy (FMA) is a frame-based ontology that represents declarative knowledge about the structural organization of the human body. Part-whole relationships play a particularly important role in this representation. In order to assure that knowledge-based applications relying on the FMA as a resource can reason about anatomy, we have modified and enhanced currently available schemes of meronymic relationships. We have introduced and defined distinct partitions for decomposing anatomical structures and attributed the part relationships in order to eliminate ambiguity and enhance specificity in the richness of meronymic relationships within the FMA

Risk Premium: Insights Over The Threshold

The aim of this paper is twofold: First to test the adequacy of Pareto distributions to describe the tail of financial returns in emerging and developed markets, and second to study the possible correlation between stock market indices observed returns and return’s extreme distributional characteristics measured by Value at Risk and Expected Shortfall. We test the empirical model using daily data from 41 countries, in the period from 1995 to 2005. The findings support the adequacy of Pareto distributions and the use of a log linear regression estimation of their parameters, as an alternative for the usually employed Hill’s estimator. We also report a significant relationship between extreme distributional characteristics and observed returns, especially for developed countries.

RISK PREMIUM: INSIGHTS OVER THE THRESHOLD

The aim of this paper is twofold: First to test the adequacy of Pareto distributions to describe the tail of financial returns in emerging and developed markets, and second to study the possible correlation between stock market indices observed returns and return’s extreme distributional characteristics measured by Value at Risk and Expected Shortfall. We test the empirical model using daily data from 41 countries, in the period from 1995 to 2005. The findings support the adequacy of Pareto distributions and the use of a log linear regression estimation of their parameters, as an alternative for the usually employed Hill’s estimator. We also report a significant relationship between extreme distributional characteristics and observed returns, especially for developed countries.