Individual Differences in EWA Learning with Partial Payoff Information

We extend experience-weighted attraction (EWA) learning to games in which only the set of possible foregone payoffs from unchosen strategies are known, and estimate parameters separately for each player to study heterogeneity. We assume players estimate unknown foregone payoffs from a strategy, by substituting the last payoff actually received from that strategy, by clairvoyantly guessing the actual foregone payoff, or by averaging the set of possible foregone payoffs conditional on the actual outcomes. All three assumptions improve predictive accuracy of EWA. Individual parameter estimates suggest that players cluster into two separate subgroups (which differ from traditional reinforcement and belief learning)

The non-Abelian feature of parton energy loss in energy dependence of jet quenching in high-energy heavy-ion collisions

One of the non-Abelian features of parton energy loss is the ratio $\Delta E_g/\Delta E_q=9/4$ between gluon and quark jets. Since jet production rate is dominated by quark jets at high $x_T=2p_T/\sqrt{s}$ and by gluon jets at low $x_T$, high $p_T$ hadron suppression in high-energy heavy-ion collisions should reflect such a non-Abelian feature. Within a leading order perturbative QCD parton model that incorporates transverse expansion and Woods-Saxon nuclear distribution, the energy dependence of large $p_T\sim 5-20$ GeV/$c$ hadron suppression is found to be sensitive to the non-Abelian feasture of parton energy loss and could be tested by data from low energy runs at RHIC or data from LHC.Comment: RevTex 4, 7 pages, 3 figure

Effect of weak measurement on entanglement distribution over noisy channels

Being able to implement effective entanglement distribution in noisy environments is a key step towards practical quantum communication, and long-term efforts have been made on the development of it. Recently, it has been found that the null-result weak measurement (NRWM) can be used to enhance probabilistically the entanglement of a single copy of amplitude-damped entangled state. This paper investigates remote distributions of bipartite and multipartite entangled states in the amplitudedamping environment by combining NRWMs and entanglement distillation protocols (EDPs). We show that the NRWM has no positive effect on the distribution of bipartite maximally entangled states and multipartite Greenberger-Horne-Zeilinger states, although it is able to increase the amount of entanglement of each source state (noisy entangled state) of EDPs with a certain probability. However, we find that the NRWM would contribute to remote distributions of multipartite W states. We demonstrate that the NRWM can not only reduce the fidelity thresholds for distillability of decohered W states, but also raise the distillation efficiencies of W states. Our results suggest a new idea for quantifying the ability of a local filtering operation in protecting entanglement from decoherence.Comment: 15 pages, 9 figures. Minor revision has been mad

Scale invariance of daily runoff time series in agricultural watersheds

International audienceFractal scaling behavior of long-term records of daily runoff time series in 32 sub-watersheds covering a wide range of size were examined using the shifted box-counting method and Hurst rescaled range (R/S) analysis. These sub-watersheds were associated with four agricultural watersheds of different climate and topography. The results showed that the records of daily runoff rate exhibited scale invariance over certain time scales. Two scaling ranges were identified from the shifted box-counting plots with a break point at about 12 months. The Hurst R/S analysis showed that the runoff time series displayed strong long-term persistence which dissipated after 15~18 months. The same fractal dimensions and Hurst exponents were obtained for the sub-watersheds within each watershed, indicating that the runoff of these sub-watersheds have similar distribution of occurrence and similar long-term memory. The existence of scale invariance in runoff time series from agricultural watersheds may have implications for extrapolating observations from gauged to ungauged watersheds

A NLO analysis on fragility of dihadron tomography in high energy AAAA collisions

The dihadron spectra in high energy $AA$ collisions are studied within the NLO pQCD parton model with jet quenching taken into account. The high $p_T$ dihadron spectra are found to be contributed not only by jet pairs close and tangential to the surface of the dense matter but also by punching-through jets survived at the center while the single hadron high $p_T$ spectra are only dominated by surface emission. Consequently, the suppression factor of such high-$p_T$ hadron pairs is found to be more sensitive to the initial gluon density than the single hadron suppression factor.Comment: 4 pages, 4 figures, proceedings for the 19th international Conference on ultra-relativistic nucleus-nucleus collisions (QM2006), Shanghai, China, November 14-20, 200

Continuous weak measurement and feedback control of a solid-state charge qubit: physical unravelling of non-Lindblad master equation

Conventional quantum trajectory theory developed in quantum optics is largely based on the physical unravelling of Lindbald-type master equation, which constitutes the theoretical basis of continuous quantum measurement and feedback control. In this work, in the context of continuous quantum measurement and feedback control of a solid-state charge qubit, we present a physical unravelling scheme of non-Lindblad type master equation. Self-consistency and numerical efficiency are well demonstrated. In particular, the control effect is manifested in the detector noise spectrum, and the effect of measurement voltage is discussed.Comment: 8 pages, 5 figure

Thermoelectric transport with electron-phonon coupling and electron-electron interaction in molecular junctions

Within the framework of nonequilibrium Green's functions, we investigate the thermoelectric transport in a single molecular junction with electron-phonon and electron-electron interactions. By transforming into a displaced phonon basis, we are able to deal with these interactions non-perturbatively. Then, by invoking the weak tunneling limit, we are able to calculate the thermoelectricity. Results show that at low temperatures, resonances of the thermoelectric figure of merit ZT occur around the sides of resonances of electronic conductance but drops dramatically to zero at exactly these resonant points. We find ZT can be enhanced by increasing electron-phonon coupling and Coulomb repulsion, and an optimal enhancement is obtained when these two interactions are competing. Our results indicate a great potential for single-molecular-junctions as good thermoelectric devices over a wide range of temperatures.Comment: 7+ pages, 3 figures, with updated appendix. Accepted by PR