2,111 research outputs found

    King without a Kingdom: Deposed King Saud and his intrigues

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    Over the years, the matter of succession has been of the most important challenges to the Saudi monarchy. Although the founder of the kingdom, ĘżAbd al-ĘżAziz Ibn Saud, had determined that the throne would be handed down to his firstborn son, his sons had to deviate from their father’s wishes not long after his death and depose the new heir, King Saud. This undermining of the order of succession at such an early stage demanded that Faisal, who took King Saud’s place, restore confidence in the principle of primogeniture and unite the royal family by establishing a system of checks and balances between the various authorities. Despite King Faisal’s efforts to stabilise the government from within, deposed King Saud had no intention of abandoning his former posi-tion, and he began a campaign to return to power by means of Saudi domestic operatives and inter-Arab forces

    Alternative Large Nc Schemes and Chiral Dynamics

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    We compare the dependences on the number of colors of the leading pion pion scattering amplitudes using the single index quark field and two index quark fields. These are seen to have different relationships to the scattering amplitudes suggested by chiral dynamics which can explain the long puzzling pion pion s wave scattering up to about 1 GeV. This may be interesting for getting a better understanding of the large Nc approach as well as for application to recently proposed technicolor models.Comment: RevTex, two-columns, 6 page

    Solar Dynamics Observatory High Gain Antenna Handover Planning

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    The Solar Dynamics Observatory (SDO) is planned to launch in early 2009 as a mission to study the solar variability and its impact on Earth. To best satisfy its science goal, SDO will fly in a geosynchronous orbit with an inclination of approximately 29 deg. The spacecraft attitude is designed so that the science instruments point directly at the Sun with high accuracy. One of SDO's principal requirements is to obtain long periods of uninterrupted observations. The observations have an extremely high data volume so SDO must be in continuous contact with the ground during the observation periods. To maintain this contact, SDO is equipped with a pair of high gain antennas (HGAs) transmitting to a pair of ground antennas at the SDO ground station (SDOGS) located in White Sands, New Mexico. Either HGA can transmit to either SDOGS antenna. Neither HGA can be powered down. During a portion of each year, each of the HGA beams will intersect with the SDO body for a portion of the orbit. The original SDO antenna contact plan used each HGA for the half of each year during which its beam would not intersect the spacecraft. No data would be lost except, possibly, when switching from one antenna to another. After this plan was adopted, further analysis showed that daily handovers would be necessary for significant periods of the year. This unexpected need for extensive handovers necessitated that a handover design be developed to minimize the impact on the mission. This antenna handover design was developed and successfully tested with simulated data using the slew rate limits from preliminary jitter analysis. Subsequent analysis provided significant revision of allowed rates requiring modification of the handover plans

    Bethe Ansatz for a Quantum Supercoset Sigma Model

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    We study an integrable conformal OSp(2m + 2|2m) supercoset model as an analog to the AdS_5 X S^5 superstring world-sheet theory. Using the known S-matrix for this system, we obtain integral equations for states of large particle density in an SU(2) sector, which are exact in the sigma model coupling constant. As a check, we derive as a limit the general classical Bethe equation of Kazakov, Marshakov, Minahan, and Zarembo. There are two distinct quantum expansions around the well-studied classical limit, the lambda^{-1/2} effects and the 1/J effects. Our approach captures the first type, but not the second.Comment: 30 pages, 1 figure, v2: references adde
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