We study Markov potential games under the infinite horizon average reward criterion. Most previous studies have been for discounted rewards. We prove that both algorithms based on independent policy gradient and independent natural policy gradient converge globally to a Nash equilibrium for the average reward criterion. To set the stage for gradient-based methods, we first establish that the average reward is a smooth function of policies and provide sensitivity bounds for the differential value functions, under certain conditions on ergodicity and the second largest eigenvalue of the underlying Markov decision process (MDP). We prove that three algorithms, policy gradient, proximal-Q, and natural policy gradient (NPG), converge to an $\epsilon$-Nash equilibrium with time complexity $O(\frac{1}{\epsilon^2})$, given a gradient/differential Q function oracle. When policy gradients have to be estimated, we propose an algorithm with $\tilde{O}(\frac{1}{\min_{s,a}\pi(a|s)\delta})$ sample complexity to achieve $\delta$ approximation error w.r.t~the $\ell_2$ norm. Equipped with the estimator, we derive the first sample complexity analysis for a policy gradient ascent algorithm, featuring a sample complexity of $\tilde{O}(1/\epsilon^5)$. Simulation studies are presented.

研究马尔可夫潜势博弈在无限时间平均回报准则下，证明基于独立策略梯度和独立自然策略梯度的算法都能在全局收敛到纳什均衡点，同时提出了渐进性和底座条件，通过梯度和微分值函数的灵敏度边界为梯度方法奠定了基础，并证明了三种算法的收敛性以及具体的时间复杂度，当需要估计策略梯度时，我们提出了一个算法并给出了样本复杂度分析，最后通过模拟研究来验证结果。

可证明的基于策略梯度法的平均奖励马尔可夫潜力博弈方法