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We study the cooperative asynchronous multi-agent multi-armed bandits problem, where each agent's active (arm pulling) decision rounds are asynchronous. That is, in each round, only a subset of agents is active to pull arms, and this subset is unknown and time-varying. We consider two models of multi-agent cooperation, fully distributed and leader-coordinated, and propose algorithms for both models that attain near-optimal regret and communications bounds, both of which are almost as good as their synchronous counterparts. The fully distributed algorithm relies on a novel communication policy consisting of accuracy adaptive and on-demand components, and successive arm elimination for decision-making. For leader-coordinated algorithms, a single leader explores arms and recommends them to other agents (followers) to exploit. As agents' active rounds are unknown, a competent leader must be chosen dynamically. We propose a variant of the Tsallis-INF algorithm with low switches to choose such a leader sequence. Lastly, we report numerical simulations of our new asynchronous algorithms with other known baselines. 

Abstract We present a pioneering achievement in the high-precision photometric calibration of CMOS-based photometry, by application of the Gaia Blue Photometer or Red Photometer (XP) spectra–based synthetic photometry method to the mini-SiTian array (MST) photometry. Through 79 repeated observations of thef02field on the night, we find good internal consistency in the calibrated MSTG_MST-band magnitudes for relatively bright stars, with a precision of about 4 mmag forG_MST ∼ 13. Results from more than 30 different nights (over 3100 observations) further confirm this internal consistency, indicating that the 4 mmag precision is stable and achievable over timescales of months. An independent external validation using spectroscopic data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope DR10 and high-precision photometric data using CCDs from Gaia DR3 reveals a zero-point consistency better than 1 mmag. Our results clearly demonstrate that CMOS photometry is on par with CCD photometry for high-precision results, highlighting the significant capabilities of CMOS cameras in astronomical observations, especially for large-scale telescope survey arrays.