Quantum state transfer from light to molecules via coherent two-color photo-association in an atomic Bose-Einstein condensate

By using a quantized input light, we theoretically revisit the coherent two-color photo-association process in an atomic Bose-Einstein condensate. Under the single-mode approximations, we show two interesting regimes of the light transmission and the molecular generation. The quantum state transfer from light to molecules is exhibited, without or with the depletion of trapped atoms.Comment: 1 figure, accepted by Eur.Phys.J.D on Dec.15,200

Distance, Growth Factor, and Dark Energy Constraints from Photometric Baryon Acoustic Oscillation and Weak Lensing Measurements

Baryon acoustic oscillations (BAOs) and weak lensing (WL) are complementary probes of cosmology. We explore the distance and growth factor measurements from photometric BAO and WL techniques and investigate the roles of the distance and growth factor in constraining dark energy. We find for WL that the growth factor has a great impact on dark energy constraints but is much less powerful than the distance. Dark energy constraints from WL are concentrated in considerably fewer distance eigenmodes than those from BAO, with the largest contributions from modes that are sensitive to the absolute distance. Both techniques have some well determined distance eigenmodes that are not very sensitive to the dark energy equation of state parameters w_0 and w_a, suggesting that they can accommodate additional parameters for dark energy and for the control of systematic uncertainties. A joint analysis of BAO and WL is far more powerful than either technique alone, and the resulting constraints on the distance and growth factor will be useful for distinguishing dark energy and modified gravity models. The Large Synoptic Survey Telescope (LSST) will yield both WL and angular BAO over a sample of several billion galaxies. Joint LSST BAO and WL can yield 0.5% level precision on ten comoving distances evenly spaced in log(1+z) between redshift 0.3 and 3 with cosmic microwave background priors from Planck. In addition, since the angular diameter distance, which directly affects the observables, is linked to the comoving distance solely by the curvature radius in the Friedmann-Robertson-Walker metric solution, LSST can achieve a pure metric constraint of 0.017 on the mean curvature parameter Omega_k of the universe simultaneously with the constraints on the comoving distances.Comment: 15 pages, 9 figures, details and references added, ApJ accepte

Government Regulation of Online Game Addiction

While the Internet has changed the world with online knowledge, communication, and collaboration, it has also introduced online addiction. Online game addiction can be severe with tragic outcomes. Most governments and organizations are yet to recognize the severity of online game addiction and the need for intervention. We briefly review the literature on online game addiction. We also summarize the limited attempts of governments to develop regulations aimed at preventing online game addiction. Special attention is paid to China and its efforts to reduce the number of hours that young people can play online. We present evidence suggesting that online game addiction is an issue that should be considered by governments everywhere and that information systems researchers can play an important role in analyzing the impacts of government regulation of online addiction and shaping regulation improvements

Coupled atomic-molecular condensates in a double-well potential: decaying molecular oscillations

We present a four-mode model that describes coherent photo-association (PA) in a double-well Bose-Einstein condensate, focusing on the $average$ molecular populations in certain parameters. Our numerical results predict an interesting strong-damping effect of molecular oscillations by controlling the particle tunnellings and PA light strength, which may provide a promising way for creating a stable molecular condensate via coherent PA in a magnetic double-well potential.Comment: 6 pages, 4 figures, submitte

Deadline Constrained Cloud Computing Resources Scheduling through an Ant Colony System Approach

Cloud computing resources scheduling is essential for executing workflows in the cloud platform because it relates to both execution time and execution cost. In this paper, we adopt a model that optimizes the execution cost while meeting deadline constraints. In solving this problem, we propose an Improved Ant Colony System (IACS) approach featuring two novel strategies. Firstly, a dynamic heuristic strategy is used to calculate a heuristic value during an evolutionary process by taking the workflow topological structure into consideration. Secondly, a double search strategy is used to initialize the pheromone and calculate the heuristic value according to the execution time at the beginning and to initialize the pheromone and calculate heuristic value according to the execution cost after a feasible solution is found. Therefore, the proposed IACS is adaptive to the search environment and to different objectives. We have conducted extensive experiments based on workflows with different scales and different cloud resources. We compare the result with a particle swarm optimization (PSO) approach and a dynamic objective genetic algorithm (DOGA) approach. Experimental results show that IACS is able to find better solutions with a lower cost than both PSO and DOGA do on various scheduling scales and deadline conditions