不违反主能量条件下的曲率诱导幻影行为与宇宙学反弹
Curvature-induced phantom mimicry and cosmological bounces without violating the Dominant Energy Condition
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中文总结 AI 辅助
本研究发现空间闭合宇宙中，正空间曲率可在不违反主能量条件下驱动有效幻影动力学，产生宇宙学反弹，并对比了真实幻影情形的演化及曲率的观测意义。
中文摘要 AI 辅助
我们证明，空间闭合的宇宙可以展现有效幻影动力学（$q<-1$），并在不违反主能量条件（DEC）的情况下抵达有限时间宇宙学事件。标准大撕裂由破坏能量条件的幻影流体驱动，而此处非零空间曲率充当主动几何贡献项：对于严格遵循DEC（$ω\ne-1$）的物质，正空间曲率本身会将减速参数驱动至$-1$以下，并使膨胀在标度因子的有限值处停止，此时哈勃参数为零而能量密度保持有限。由于曲率还使哈勃半径在该点保持正则，这一事件自然被解释为宇宙学反弹而非破坏性奇点。我们将这种保持DEC的机制与真实幻影情形（$ω<-1$）进行对比，后者在相同的闭合几何中会产生早期反弹及随后的晚期大撕裂，并对曲率贡献的观测现状进行了评述。
英文摘要
We explore the active geometric contribution of spatial curvature in a closed universe, distinguishing between kinematic superacceleration and the strict violation of matter energy conditions. We demonstrate that for pressureless matter obeying the Dominant Energy Condition (DEC), positive spatial curvature does not induce a phantom regime, but leads to a decelerating expansion that culminates in a late-time turnaround ($\dot{H}<0$). At this finite-scale moment, the expansion ceases and the apparent horizon stays regular, signaling the beginning of an eventual Big Crunch. We contrast this behavior with the genuine phantom case ($ω<-1$), where positive curvature introduces a distinct, early finite-radius expansion bounce ($\dot{H}>0$) that cannot prevent the inevitable late-time Big Rip singularity. Finally, we contextualize these results, discussing how positive spatial curvature can dynamically mimic phantom phenomenology and permit geodesically complete cosmologies without relying on exotic, energy-condition-violating matter.
发表机构
- Facultad de Física, Universidad Veracruzana（韦拉克鲁斯大学物理学院）
- Instituto de Física, Pontificia Universidad Católica de Valparaíso（天主教瓦尔帕莱索大学物理研究所）
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