论文标题
关于分布式多数协议的层次结构
On the Hierarchy of Distributed Majority Protocols
论文作者
论文摘要
我们研究$ n $ n $代理之间的共识问题,定义为如下。最初,每个代理都持有两个可能的意见之一。目的是达成共识配置,每个代理商都具有相同的意见。为此,代理商会根据采样意见随机对其他代理进行随机对其他代理进行采样,并根据简单的更新功能更新意见。 我们考虑两个通信模型:八卦模型和人口模型的变体。在八卦模型中,用并行同步的弹药激活了代理。在人群模型中,一种代理以一系列离散的时间步骤激活另一个代理。对于这两种模型,我们分析了以下自然家族的多数过程,称为$ j $ -Majority:激活时,每个代理样本$ j $ j $其他代理在随机(替换)中均匀(替换),并在样本中采用多数意见(随机打破纽带)。作为我们的主要结果,我们在多数协议之间显示了一个层次结构:$(J+1)$ - 多数($ J> 1 $)随机收敛的速度比任何初始意见配置的$ j $ -majority都要快。在我们的分析中,我们使用Strassen的定理证明存在耦合。对于Berenbrink等人提出的一个公开问题,这给出了两个意见的案例的肯定答案。 [2017]。
We study the Consensus problem among $n$ agents, defined as follows. Initially, each agent holds one of two possible opinions. The goal is to reach a consensus configuration in which every agent shares the same opinion. To this end, agents randomly sample other agents and update their opinion according to a simple update function depending on the sampled opinions. We consider two communication models: the gossip model and a variant of the population model. In the gossip model, agents are activated in parallel, synchronous rounds. In the population model, one agent is activated after the other in a sequence of discrete time steps. For both models we analyze the following natural family of majority processes called $j$-Majority: when activated, every agent samples $j$ other agents uniformly at random (with replacement) and adopts the majority opinion among the sample (breaking ties uniformly at random). As our main result we show a hierarchy among majority protocols: $(j+1)$-Majority (for $j > 1$) converges stochastically faster than $j$-Majority for any initial opinion configuration. In our analysis we use Strassen's Theorem to prove the existence of a coupling. This gives an affirmative answer for the case of two opinions to an open question asked by Berenbrink et al. [2017].