Abstract The discrepancy between the vacuum energy density predicted by quantum field theory and that inferredfrom cosmological observations remains one of the most severe unresolved problems in theoretical physics.This work argues that the persistence of this problem signals not merely a failure of calculation, buta deeper conceptual tension between background-dependent quantum field theory and the dynamicalspacetime of general relativity. By tracing the historical and conceptual evolution of the cosmologicalconstant, and by critically reviewing dominant solution strategies, it is suggested that the difficulty arisesfrom treating quantum vacuum energy as an independent material source rather than as a structuralaspect of spacetime itself. On this basis, the paper introduces the notion of spacetime self-energy asa conceptual perspective: quantum vacuum energy is interpreted as an intrinsic energetic characteristicof spacetime, rather than as a gravitating substance residing within it. From this viewpoint, the vacuumcatastrophe is reframed as a category mismatch between microphysical identifiers and macrophysicaldynamical parameters, rather than as a numerical inconsistency requiring fine-tuning. The discussion isprimarily conceptual, but it outlines possible phenomenological implications for dark energy dynamicsand early-universe physics. The paper concludes that a reconceptualization of the status of vacuumenergy—rather than further technical adjustments within the current paradigm—may be necessary forgenuine progress on this foundational issue. 【中文摘要:时空实体论 IV】 量子场论预测的真空能量密度与宇宙学观测推导值之间的巨大差异,依然是理论物理学中最严峻的未解难题之一。本文指出,这一问题的长期存在不仅标志着计算的失败,更反映了背景依赖的量子场论与广义相对论动力学时空之间深层的概念张力。 通过追溯宇宙常数的历史与概念演变,并对主流解决方案进行批判性审查,本文提出:困难的根源在于将量子真空能视为一种独立的物质源,而非时空自身的结构属性。 在此基础上,本文引入了**“时空自能”(Spacetime Self-Energy)**这一概念视角:量子真空能被解释为时空内在的能量特征,而非驻留在时空内部并产生引力的物质。 核心审计结论: 从这一视角出发,“真空灾难”被重构为微观物理标识符与宏观动力学参数之间的“范畴错配”,而非需要精细调节的数值不一致。 虽然讨论主要集中在概念层面,但本文概述了其对暗能量动力学和早期宇宙物理可能产生的观测影响。本文结论认为,要在此基础性问题上取得实质性进展,必须对真空能的状态进行概念重构,而非在现有范式下进行更多的技术修正。