We investigate stochastic combinatorial multi-armed bandit with semi-bandit feedback (CMAB). In CMAB, the question of the existence of an efficient policy with an optimal asymptotic regret (up to a factor poly-logarithmic with the action size) is still open for many families of distributions, including mutually independent outcomes, and more generally the multivariate sub-Gaussian family. We propose to answer the above question for these two families by analyzing variants of the Combinatorial Thompson Sampling policy (CTS). For mutually independent outcomes in $[0,1]$, we propose a tight analysis of CTS using Beta priors. We then look at the more general setting of multivariate sub-Gaussian outcomes and propose a tight analysis of CTS using Gaussian priors. This last result gives us an alternative to the Efficient Sampling for Combinatorial Bandit policy (ESCB), which, although optimal, is not computationally efficient.

本文研究了采用半智能反馈的随机组合多臂赌博机问题。研究中提出了解决对于两种不同分布情况下是否存在效率最优、渐进遗憾最小算法的问题。通过分别采用Beta先验和高斯先验对 Combinatorial Thompson Sampling 策略进行了分析，进而找到了这两种分布情况下的算法解决方案，从而得出计算效率上优于 Efficient Sampling for Combinatorial Bandit 策略的结论。

组合半臂老虎机的汤普森抽样的统计效率