Bounds on slow roll and the de Sitter Swampland
Bounds on slow roll and the de Sitter Swampland
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DOI：
10.1007/jhep11(2019)075
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发表时间：
2019-11-12
影响因子：
5.4
通讯作者：
Krishnan, Chethan
中科院分区：
文献类型：
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作者：
Garg, Sumit K.;Krishnan, Chethan
最近引入的de Sitter [17]的沼泽地准则可以被视为慢滚参数λ（V）的小的（层次上大的）界限。这使我们更仔细地考虑另一个慢滚参数eta（V），并且我们推测该界不一定在η（V）上，而是在慢滚本身上。因此，德西特沼泽猜想的一个自然的改进是，在任何UV完备理论中，慢滚在普朗克单位的O（1）处被违反。一个推论是，如果eta（V）小于或近似于-O（1）成立，则η（V）不一定是O（1）。我们考虑了de Sitter在IIA/IIB弦理论中的各种快子树层次结构（以及密切相关的暴胀模型），这些结构表面上违反了[17]，并表明它们与这个改进版本的界限是一致的。慢滚的措辞使得两个版本的猜想在暴胀期间e折叠的数量很高时都陷入困境的原因变得合理。我们推测，一种逃避束缚的方法可能是拥有大量的场，就像N-膨胀一样。
The recently introduced swampland criterion for de Sitter [17] can be viewed as a (hierarchically large) bound on the smallness of the slow roll parameter epsilon(V). This leads us to consider the other slow roll parameter eta(V) more closely, and we are lead to conjecture that the bound is not necessarily on epsilon(V), but on slow roll itself. A natural refinement of the de Sitter swampland conjecture is therefore that slow roll is violated at O(1) in Planck units in any UV complete theory. A corollary is that epsilon(V) need not necesarily be O(1), if eta(V) less than or similar to -O(1) holds. We consider various tachyonic tree level constructions of de Sitter in IIA/IIB string theory (as well as closely related models of inflation), which superficially violate [17], and show that they are consistent with this refined version of the bound. The phrasing in terms of slow roll makes it plausible why both versions of the conjecture run into trouble when the number of e-folds during inflation is high. We speculate that one way to evade the bound could be to have a large number of fields, like in N-flation.