Two-photon detuning and decoherence in cavity electromagnetically induced transparency for quantized fields

The interaction of a quantized field with three-level atoms in $\Lambda$ configuration inside a two-mode cavity is analyzed in the small noise approximation. The atoms are in a two-photon detuning with respect to the carriers of the field. We calculate the stationary quadrature noise spectrum of the field outside the cavity in the case where the input probe field is a squeezed state and the input pump field is a coherent state. The mean value of the field is unaltered in all the analysis: the atoms shows electromagnetically induced transparency (EIT). The effect of the atoms' base level decoherence in the cavity output field is also studied. It is found that the output field is very sensitive to two-photon detuning.Comment: 8 page

A Model of Casino Gambling

We show that prospect theory offers a rich theory of casino gambling, one that captures several features of actual gambling behavior. First, we demonstrate that, for a wide range of preference parameter values, a prospect theory agent would be willing to gamble in a casino even if the casino only offers bets with no skewness and with zero or negative expected value. Second, we show that the probability weighting embedded in prospect theory leads to a plausible time inconsistency: at the moment he enters a casino, the agent plans to follow one particular gambling strategy; but after he starts playing, he wants to switch to a different strategy. The model therefore predicts heterogeneity in gambling behavior: how a gambler behaves depends on whether he is aware of the time inconsistency; and, if he is aware of it, on whether he can commit in advance to his initial plan of action.

Opacity of electromagnetically induced transparency for quantum fluctuations

We analyze the propagation of a pair of quantized fields inside a medium of three-level atoms in $\Lambda$ configuration. We calculate the stationary quadrature noise spectrum of the field after propagating through the medium, in the case where the probe field is in a squeezed state and the atoms show electromagnetically induced transparency (EIT). We find an oscillatory transfer of the initial quantum properties between the probe and pump fields which is most strongly pronounced when both fields have comparable Rabi frequencies. This implies that the quantum state measured after propagation can be completely different from the initial state, even though the mean values of the field are unaltered

Message handling system concepts and services in a land mobile satellite system

A network architecture containing the capabilities offered by the Message Handling System (MHS) to the PRODAT Land Mobile Satellite System (LMSS) is described taking into account the constraints of a preexisting satellite system which is going to become operational. The mapping between MHS services and PRODAT requirements is also reported and shows that the supplied performance can be significantly enhanced to both fixed and mobile users. The impact of the insertion of additional features on the system structure, especially on the centralized control unit, are also addressed

Patrones de actividad y abundancias estacionales del Flamenco Andino (Phoe-nicoparrus andinus) en dos humedales contrastantes en Argentina

El Flamenco Andino utilizade forma complementaria y alternativa humedales altoandinos de Argentina, Bolivia, Chile y Perú,además de humedales en las tierras bajas de Argentina. Estudios previos se enfocaron en su com-portamiento en sitios andinos, pero no existen al momento estudios de este tipo en sitios de tierrasbajas. Debido a esto, el objetivo del estudio fue analizar los patrones de actividad, de despliegues decortejo y abundancias de esta especie de flamenco en dos humedales contrastantes. Los sitios de es-tudio fueron: la Laguna de Vilama, en el noroeste de Argentina y a 4500 m s.n.m., la cual es utilizadaen el verano durante el período reproductivo; y la Laguna Melincué, en la planicie del centro-este deArgentina y a 84 m s.n.m., que es utilizada durante el período no reproductivo invernal. Entre sitios yentre años hubo marcadas diferencias en la abundancia y en los patrones de actividad. En la Lagunade Vilama, los flamencos se alimentaron durante la mayor parte del tiempo (95%), mientras que enla Laguna Melincué, los flamencos mostraron un rango más amplio de comportamientos, destinandosólo el 60% del tiempo a alimentarse. No registramos despliegues nupciales (marchas) en la Lagunade Vilama, mientras que en la Laguna Melincué sí registramos marchas, las cuales fueron másfrecuentes y de mayor duración en aquellos años con mayores abundancias de flamencos. Las dife-rencias en actividades entre los sitios estarían asociadas a la calidad y disponibilidad de recursos yal momento del ciclo reproductivo, donde los sitios de tierras bajas proveen hábitats críticos paralas actividades de cortejo que finalmente influyen el éxito reproductivo en los humedales de los AltosAndes.The Andean Flamingo (Phoenicoparrus andinus), one of three flamingo species in southernSouth America makes complementary and alternative use of high Andean wetlands in Argentina, Bolivia,Chile and Peru, and lowland wetlands in Argentina over its life cycle. Previous studies have focused onits behavior in Andean sites, but there are no such studies in lowland sites. Therefore, we analyzed theactivity patterns, courtship displays, and individual abundance of this flamingo species at two contrastingwetland sites, Laguna de Vilama, located at 4500 m a.s.l. in northwestern Argentina and used in summerduring the breeding season, and Laguna Melincué, a lowland wetland located at 84 m a.s.l. in the plainsof central east Argentina and used in winter during the non-breeding season. There were marked differ-ences in flamingo abundance and activity patterns between sites and years. In Laguna de Vilama, fla-mingos were feeding most of the time (95%), whereas at Laguna Melincué, flamingos showed a broaderrange of behaviors, with only a 60% of time spent feeding. We did not record marching displays atLaguna de Vilama, whereas at Laguna Melincué we recorded marching events in each of the three studyyears, being more frequent and lasting longer in the year with higher flamingo abundance. The differ-ences in behaviors at these sites are associated with resource quality and availability and with timing ofthe reproductive cycle, with lowland wetlands providing critical habitats for courtship displays that influ-ence reproductive success of this species breeding colonies in high Andean wetlands. Accepted 1 Octo-ber 2014Fil: Derlindati, Enrique Javier. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto Geonorte; Argentina. Grupo de Conservación Flamencos Altoandinos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Romano, Marcelo C. Grupo de Conservación Flamencos Altoandinos; Argentina. Centro de Investigaciones en Biodiversidad y Ambiente. Rosario; ArgentinaFil: Cruz, Nancy N.. Grupo de Conservación Flamencos Altoandinos; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto Geonorte; ArgentinaFil: Barisón, Caterina. Grupo de Conservación Flamencos Altoandinos; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Arengo, Felicity. Grupo de Conservación Flamencos Altoandinos; Argentina. American Museum Of Natural History; Estados UnidosFil: Barberis, Ignacio Martín. Grupo de Conservación Flamencos Altoandinos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Feedback in a cavity QED system for control of quantum beats

Conditional measurements on the undriven mode of a two-mode cavity QED system prepare a coherent superposition of ground states which generate quantum beats. The continuous system drive induces decoherence through the phase interruptions from Rayleigh scattering, which manifests as a decrease of the beat amplitude and an increase of the frequency of oscillation. We report recent experiments that implement a simple feedback mechanism to protect the quantum beat. We continuously drive the system until a photon is detected, heralding the presence of a coherent superposition. We then turn off the drive and let the superposition evolve in the dark, protecting it against decoherence. At a later time we reinstate the drive to measure the amplitude, phase, and frequency of the beats. The amplitude can increase by more than fifty percent, while the frequency is unchanged by the feedback.Comment: 13 pages, 5 figures, ICAP 2012 23rd International Conference on Atomic Physic

Realization Utility

A number of authors have suggested that investors derive utility from realizing gains and losses on assets that they own. We present a model of this “realization utility,” analyze its predictions, and show that it can shed light on a number of puzzling facts. These include the disposition effect, the poor trading performance of individual investors, the higher volume of trade in rising markets, the effect of historical highs on the propensity to sell, the individual investor preference for volatile stocks, the low average return of volatile stocks, and the heavy trading associated with highly valued assets.

Pseudo-K\"ahler Lie algebras with abelian complex structures

We study Lie algebras endowed with an abelian complex structure which admit a symplectic form compatible with the complex structure. We prove that each of those Lie algebras is completely determined by a pair (U,H) where U is a complex commutative associative algebra and H is a sesquilinear hermitian form on U which verifies certain compatibility conditions with respect to the associative product on U. The Riemannian and Ricci curvatures of the associated pseudo-K\"ahler metric are studied and a characterization of those Lie algebras which are Einstein but not Ricci flat is given. It is seen that all pseudo-K\"ahler Lie algebras can be inductively described by a certain method of double extensions applied to the associated complex asssociative commutative algebras