Spherical Proca Stars (PSs) are regarded as the ground state amongst the family of PSs. In accordance, spherical PSs are thought to have a fundamental branch of stable solutions. In this , we provide energetic, morphological and dynamical evidence that spherical PSs are actually excited states. The ground state is shown to be a family of static, non-spherical, in fact , PSs. The spherical stars in the fundamental branch, albeit stable against spherical perturbations, turn out to succumb to dynamics, undergoing an isometry breaking into prolate PSs. We also provide evidence for the dynamical formation of prolate PSs, starting from dilute initial data, via gravitational cooling. Consequently, PSs provide a remarkable example of (possibly compact) relativistic stars, in General Relativity minimally coupled to a simple, physical, field theory model, where staticity plus stability implies non-sphericity.

中文翻译：

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普罗卡星的非球形基态

球形普罗卡星 (PS) 被视为 PS 家族中的基态。因此，球形 PS 被认为具有稳定解的基本分支。在本文中，我们提供了能量、形态和动力学证据，证明球形 PS 实际上是激发态。基态被证明是一系列静态的、非球形的、实际上是PS。基本分支中的球形恒星虽然在球形扰动下保持稳定，但最终屈服于动力学，经历等距分解成长长的 PS。我们还提供了长长 PS 的动态形成的证据，从稀释的初始数据开始，通过重力冷却。因此，PS 提供了一个（可能是致密的）相对论恒星的显着例子，在广义相对论中，它与简单的物理场论模型最低限度地耦合，其中静态加上稳定性意味着非球形。