发表机构
Universidade de Lisboa; Instituto Superior Técnico; Centro de Astrofísica e Gravitação (CENTRA)（里斯本大学; 技术高等学院; 天体物理学与引力中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文从Einstein-complex-Proca理论直接推导球对称Proca星的压强各向异性，发现应力在核心径向主导、包层切向主导，并在首个质量极大值处各向异性达约21%，为各向异性玻色子致密天体提供第一性原理基准。
AI 中文摘要
相对论性恒星中的压强各向异性通常通过唯象闭合条件来规定，这掩盖了其微观起源以及与应力-能量守恒的关系。本文直接从最小耦合的Einstein-complex-Proca理论中推导出该各向异性。对于球对称Proca星，主压强差具有精确的在壳形式，其符号仅由局域质量壳阈值控制。应力在核心处呈径向主导，在固定引力红移的表面上发生反转，并在包层中变为切向主导。在第一个质量极大值处，分数各向异性在密度极大值附近达到约21%，而反转区域之外包含约9%的质量。其精确的大气极限约为24%，其大小与标量玻色子星极限相等，符号相反。由于通常的局域流体变量在穿越点处保持非零，因此由它们构造的任何符号确定的闭合条件都无法重现该剖面。这些结果识别出一种无需额外相互作用即可产生的内禀矢量型应力反转，并为各向异性玻色子致密天体提供了第一性原理基准。
英文摘要
Pressure anisotropy in relativistic stars is commonly prescribed through a phenomenological closure, obscuring its microscopic origin and relation to stress-energy conservation. Here it is derived directly from the minimally coupled Einstein-complex-Proca theory. For spherical Proca stars, the principal-pressure difference admits an exact on-shell form whose sign is controlled solely by the local mass-shell threshold. The stress is radially dominated in the core, reverses on a surface of fixed gravitational redshift, and becomes tangentially dominated in the envelope. At the first mass maximum, the fractional anisotropy reaches about 21% near the density maximum, whilst the region beyond the reversal contains about 9% of the mass. Its exact atmospheric limit is approximately 24%, equal in magnitude and opposite in sign to the scalar-boson-star limit. Because the usual local fluid variables remain non-zero at the crossing, no sign-definite closure constructed from them can reproduce the profile. These results identify an intrinsically vectorial stress reversal, generated without additional interactions, and provide a first-principles benchmark for anisotropic bosonic compact objects.
Comments9 pages, 3 figures, 1 table. Accepted for publication in Physics Letters B
DOI：10.1016/j.physletb.2026.140940
