The COVID-19 pandemic brought upon a massive wave of disinformation, exacerbating polarization in the increasingly divided landscape of online discourse. In this context, popular social media users play a major role, as they have the ability to broadcast messages to large audiences and influence public opinion. In this paper, we make use of openly available data to study the behavior of popular users discussing the pandemic on Twitter. We tackle the issue from a network perspective, considering users as nodes and following relationships as directed edges. The resulting network structure is modeled by embedding the actors in a latent social space, where users closer to one another have a higher probability of following each other. The results suggest the existence of two distinct communities, which can be interpreted as "generally pro" and "generally against" vaccine mandates, corroborating existing evidence on the pervasiveness of echo chambers on the platform. By focusing on a number of notable users, such as politicians, activists, and news outlets, we further show that the two groups are not entirely homogeneous, and that not just the two poles are represented. To the contrary, the latent space captures an entire spectrum of beliefs between the two extremes, demonstrating that polarization, while present, is not the only driver of the network, and that more moderate, "central" users are key players in the discussion.

翻译：COVID-19疫情引发了一波大规模的虚假信息浪潮，加剧了本已日益分裂的网络话语格局中的极化现象。在此背景下，热门社交媒体用户发挥着重要作用，因为他们能够向广大受众传播信息并影响公众舆论。本文利用公开可获取的数据，研究了在Twitter上讨论疫情的热门用户的行为。我们从网络视角出发，将用户视为节点，将关注关系视为有向边，并构建了相应的网络结构。通过将行动者嵌入潜在社会空间来建模这一网络结构，其中距离较近的用户之间互相关注的概率更高。结果表明存在两个不同的社群，可被解读为“普遍支持”与“普遍反对”疫苗强制令，这印证了关于该平台上回音壁现象普遍存在的现有证据。通过聚焦若干知名用户（如政客、活动人士和新闻媒体），我们进一步表明这两个群体并非完全同质化，且并非仅代表两极对立。相反，潜在空间捕捉到了介于两个极端之间的整个信念谱系，证明极化现象虽存在但并非驱动网络的唯一因素，而较为温和的“居中”用户才是讨论中的关键参与者。