991 research outputs found
Interactive Restless Multi-armed Bandit Game and Swarm Intelligence Effect
We obtain the conditions for the emergence of the swarm intelligence effect
in an interactive game of restless multi-armed bandit (rMAB). A player competes
with multiple agents. Each bandit has a payoff that changes with a probability
per round. The agents and player choose one of three options: (1)
Exploit (a good bandit), (2) Innovate (asocial learning for a good bandit among
randomly chosen bandits), and (3) Observe (social learning for a good
bandit). Each agent has two parameters to specify the decision:
(i) , the threshold value for Exploit, and (ii) , the probability
for Observe in learning. The parameters are uniformly
distributed. We determine the optimal strategies for the player using complete
knowledge about the rMAB. We show whether or not social or asocial learning is
more optimal in the space and define the swarm intelligence
effect. We conduct a laboratory experiment (67 subjects) and observe the swarm
intelligence effect only if are chosen so that social learning
is far more optimal than asocial learning.Comment: 18 pages, 4 figure
Weighing the Light Gravitino Mass with Weak Lensing Surveys
We explore the discovery potential of light gravitino mass m_{3/2} by
combining future cosmology surveys and collider experiments. The former probe
the imprint of light gravitinos in the cosmic matter density field, whereas the
latter search signatures of a supersymmetry breaking mechanism. Free-streaming
of light gravitinos suppresses the density fluctuations at galactic and
sub-galactic length scales, where weak gravitational lensing can be used as a
powerful probe. We perform numerical simulations of structure formation to
quantify the effect. We then run realistic ray-tracing simulations of
gravitational lensing to measure the cosmic shear in models with light
gravitino. We forecast the possible reach of future wide-field surveys by
Fisher analysis; the light gravitino mass can be determined with an accuracy of
m_{3/2}=4\pm 1 eV by a combination of the Hyper Suprime Cam survey and cosmic
microwave background anisotropy data obtained by Planck satellite. The
corresponding accuracy to be obtained by the future Large Synoptic Survey
Telescope is \delta m_{3/2}=0.6 eV. Data from experiments at Large Hadron
Collider at 14 TeV will provide constraint at m_{3/2} \simeq 5 eV in the
minimal framework of gauge-mediated supersymmetry breaking (GMSB) model. We
conclude that a large class of the GMSB model can be tested by combining the
cosmological observations and the collider experiments.Comment: 22 pages, 9 figure
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