Modular invariant inflation
Modular invariant inflation
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模不变膨胀
DOI：
10.1088/1475-7516/2016/08/014
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
Yuko Urakawa
中科院分区：
文献类型：
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作者：
Tatsuo Kobayashi;Daisuke Nitta;Yuko Urakawa
模不变性是弦理论中一种引人注目的对称性，它可以控制弦的修正。在本文中，我们研究了模不变性的一个现象学结果，假设这种对称性在四维（4D）低能量有效场论中也被保留。作为一个具体的设置，我们考虑一个模场T，其在四维有效场论中的贡献在模变换下保持不变，并研究由T驱动的膨胀。模不变性限制了标量势的一种可能形式。因此，膨胀的大场模型很难实现。同时，一个小场的暴胀模型仍然可以容纳在这个有限的设置。在慢滚膨胀期间追踪的标量势模拟了山顶势V ht，但它也与V ht有不可忽略的偏差。探测在这个模型中预测的原始引力波是相当具有挑战性的。然而，我们认为，在这种情况下，通过结合再加热过程中可以自完全确定的信息，仍然有可能伪造该模型。
Modular invariance is a striking symmetry in string theory, which may keep stringy corrections under control. In this paper, we investigate a phenomenological consequence of the modular invariance, assuming that this symmetry is preserved as well as in a four dimensional (4D) low energy effective field theory. As a concrete setup, we consider a modulus field T whose contribution in the 4D effective field theory remains invariant under the modular transformation and study inflation drived by T. The modular invariance restricts a possible form of the scalar potenntial. As a result, large field models of inflation are hardly realized. Meanwhile, a small field model of inflation can be still accomodated in this restricted setup. The scalar potential traced during the slow-roll inflation mimics the hilltop potential V ht, but it also has a non-negligible deviation from V ht. Detecting the primordial gravitational waves predicted in this model is rather challenging. Yet, we argue that it may be still possible to falsify this model by combining the information in the reheating process which can be determined self-completely in this setup.