Quantum Game with Restricted Matrix Strategies

We study a quantum game played by two players with restricted multiple strategies. It is found that in this restricted quantum game Nash equilibrium does not always exist when the initial state is entangled. At the same time, we find that when Nash equilibrium exists the pay off function is usually different from that in the classical counterpart except in some special cases. This presents an explicit example where quantum game and classical game may differ. When designing a quantum game with limited strategies, the allowed strategy should be carefully chosen according to the type of initial state.Comment: 5 pages and 3 figure

Glueball relevant study on isoscalars from Nf=2N_f=2 lattice QCD

We perform a glueball-relevant study on isoscalars based on anisotropic $N_f=2$ lattice QCD gauge configurations. In the scalar channel, we identify the ground state obtained through gluonic operators to be a single-particle state through its dispersion relation. When $q\bar{q}$ operator is included, we find the mass of this state does not change, and the $q\bar{q}$ operator couples very weakly to this state. So this state is most likely a glueball state. For pseudoscalars, along with the exiting lattice results, our study implies that both the conventional $q\bar{q}$ state $\eta_2$ (or $\eta'$ in flavor $SU(3)$) and a heavier glueball-like state with a mass of roughly 2.6 GeV exist in the spectrum of lattice QCD with dynamical quarks.Comment: 8 pages, 3 figures, 3 tables, talk presented at the 35th International Symposium on Lattice Field Theory, 18-24 June 2017, Granada, Spai

A WOA-based optimization approach for task scheduling in cloud Computing systems

Task scheduling in cloud computing can directly affect the resource usage and operational cost of a system. To improve the efficiency of task executions in a cloud, various metaheuristic algorithms, as well as their variations, have been proposed to optimize the scheduling. In this work, for the first time, we apply the latest metaheuristics WOA (the whale optimization algorithm) for cloud task scheduling with a multiobjective optimization model, aiming at improving the performance of a cloud system with given computing resources. On that basis, we propose an advanced approach called IWC (Improved WOA for Cloud task scheduling) to further improve the optimal solution search capability of the WOA-based method. We present the detailed implementation of IWC and our simulation-based experiments show that the proposed IWC has better convergence speed and accuracy in searching for the optimal task scheduling plans, compared to the current metaheuristic algorithms. Moreover, it can also achieve better performance on system resource utilization, in the presence of both small and large-scale tasks

Unitarity estimation for quantum channels

The unitarity is a measure giving information on how much a quantum channel is unitary. Learning the unitarity of an unknown quantum channel $\mathcal{E}$ is a basic and important task in quantum device certification and benchmarking. Generally, this task can be performed with either coherent or incoherent access. For coherent access, there are no restrictions on learning algorithms; while for incoherent access, at each time, after preparing the input state and applying $\mathcal{E}$, the output is measured such that no coherent quantum information can survive or be acted upon by $\mathcal{E}$ again. Quantum algorithms with only incoherent access allow practical implementations without the use of persistent quantum memory, and thus is more suitable for near-term devices. In this paper, we study unitarity estimation in both settings. For coherent access, we provide an ancilla-efficient algorithm that uses $O(\epsilon^{-2})$ calls to $\mathcal{E}$ where $\epsilon$ is the required precision; we show that this algorithm is query-optimal, giving a matching lower bound $\Omega(\epsilon^{-2})$. For incoherent access, we provide a non-adaptive, non-ancilla-assisted algorithm that uses $O(\sqrt{d}\cdot \epsilon^{-2})$ calls to $\mathcal{E}$, where $d$ is the dimension of the system that $\mathcal{E}$ acts on; we show that this algorithm cannot be substantially improved, giving an $\Omega(\sqrt{d}+\epsilon^{-2})$ lower bound, even if adaptive strategies and ancilla systems are allowed. As part of our results, we settle the query complexity of the distinguishing problem for depolarizing and unitary channels with incoherent access by giving a matching lower bound $\Omega(\sqrt{d})$, improving the prior best lower bound $\Omega(\sqrt[3]{d})$ by Aharonov, Cotler, and Qi (Nat. Commun. 2022) and Chen, Cotler, Huang, and Li (FOCS 2021).Comment: 35 page

Does ISO 9000 certification benefit service firms?

This paper examines whether ISO 9000 certification benefits service firms in terms of their financial performance and promotes sustainable improvement. We argue that in a developing country setting such as China, the massive benefits brought by the signalling effect of the certification can discourage firms' motivation to fully implement the standard of certification and lead to the decline of investment on productivity-improving activities. In other words, the certification may have negative effects on the productivity of certified firms. We investigate 89,024 firms in Chinese service industries to assess the impacts of the certification on sales, productivity and profitability of these firms. To address the potential selection bias of ISO 9000 certification, the Propensity Score Matching method and Coarsened Exact Matching method were used. Our key findings are that the ISO 9000 certification does help to increase the total amount of sales, but it decreases the productivity and profitability of these certified service firms. We also find that earlier certifiers seem to gain larger advantage in sales but more reduction in productivity, and firms with higher level of technology intensity seem to obtain a larger increase in sales and less productivity loss after receiving their ISO 9000 certification

Symmetries and Lie algebra of the differential-difference Kadomstev-Petviashvili hierarchy

By introducing suitable non-isospectral flows we construct two sets of symmetries for the isospectral differential-difference Kadomstev-Petviashvili hierarchy. The symmetries form an infinite dimensional Lie algebra.Comment: 9 page

Origination of an X-Linked Testes Chimeric Gene by Illegitimate Recombination in <i>Drosophila</i>

The formation of chimeric gene structures provides important routes by which novel proteins and functions are introduced into genomes. Signatures of these events have been identified in organisms from wide phylogenic distributions. However, the ability to characterize the early phases of these evolutionary processes has been difficult due to the ancient age of the genes or to the limitations of strictly computational approaches. While examples involving retrotransposition exist, our understanding of chimeric genes originating via illegitimate recombination is limited to speculations based on ancient genes or transfection experiments. Here we report a case of a young chimeric gene that has originated by illegitimate recombination in Drosophila. This gene was created within the last 2–3 million years, prior to the speciation of Drosophila simulans, Drosophila sechellia, and Drosophila mauritiana. The duplication, which involved the Bällchen gene on Chromosome 3R, was partial, removing substantial 3′ coding sequence. Subsequent to the duplication onto the X chromosome, intergenic sequence was recruited into the protein-coding region creating a chimeric peptide with ~ 33 new amino acid residues. In addition, a novel intron-containing 5′ UTR and novel 3′ UTR evolved. We further found that this new X-linked gene has evolved testes-specific expression. Following speciation of the D. simulans complex, this novel gene evolved lineage-specifically with evidence for positive selection acting along the D. simulans branch.</p