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arXiv 1809.00726hep-thastro-ph.CO
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沼泽、精华与真空能量

The Swampland, Quintessence and the Vacuum Energy

M. C. David Marsh

摘要:

最近有人指出,弦论不承认德西特真空,而这一精髓解释了当前宇宙加速膨胀的时代。对这种情况的一个提议的关键预测是暗区的时变耦合,由不断发展的精华场引起。我们注意到,具有不同耦合的宇宙学模型遭受严重的量子校正问题,超出了所有的精髓模型所共有的问题。真空能量依赖于理论中所有的质量和耦合,即使参数的微小变化也会导致对有效势的巨大修正。我们发现,在一致的量子理论中,具有不同参数的精粹模型可以通过以下方式实现:1)强制执行特殊水平的微调; 2)实现某种未知的机制,以前所未有的精度取消对有效势的所有不必要的贡献;或3)确保精粹场只耦合到非常轻的状态,而不会对重场产生反作用。

英文摘要:

It has recently been conjectured that string theory does not admit de Sitter vacua, and that quintessence explains the current epoch of accelerated cosmic expansion. A proposed, key prediction of this scenario is time-varying couplings in the dark sector, induced by the evolving quintessence field. We note that cosmological models with varying couplings suffer from severe problems with quantum corrections, beyond those shared by all quintessence models. The vacuum energy depends on all masses and couplings of the theory, and even small variations of parameters can lead to overwhelmingly large corrections to the effective potential. We find that quintessence models with varying parameters can be realised in consistent quantum theories by either: 1) enforcing exceptional levels of fine-tuning; 2) realising some unknown mechanism that cancels all undesirable contributions to the effective potential with unprecedented accuracy; or 3) ensuring that the quintessence field couples exclusively to very light states, and does not backreact on heavy fields.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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