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arXiv 0710.3074hep-ph
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F项混合暴胀中谱指数的降阶

Reducing the spectral index in F-term hybrid inflation

C. Pallis

摘要:

我们考虑了一类F项混合暴胀(FHI)的超对称模型,它可以与超对称大统一联系起来。如果对应于枢轴尺度k_*=0.002/Mpc的e折叠数约为50,则预测的标量谱指数n_s不能小于0.97,并且可以超过1(包括最小超引力的修正)。这些结果与用标准幂律宇宙学模型拟合的三年威尔金森微波各向异性探测器数据(含冷暗物质和宇宙学常数)略有一致。然而,n_s可以通过两种机制来减小:(i)利用准正则Kahler势并方便地选择符号;(ii)限制k_* 在FHI过程中所遭受的e-折叠次数。在情形(i)中,我们研究了n_s在暴胀路径上不产生势能极大值和极小值的可能的减小。解决水平和平坦度问题所需要的额外的e-折叠,可以通过随后的快卷[慢卷]模膨胀阶段来产生,所述模膨胀阶段是通过一个弦模来实现的,所述弦模不在模块膨胀开始之前获得有效质量。

英文摘要:

We consider a class of well motivated supersymmetric models of F-term hybrid inflation (FHI) which can be linked to the supersymmetric grand unification. The predicted scalar spectral index n_s cannot be smaller than 0.97 and can exceed unity including corrections from minimal supergravity, if the number of e-foldings corresponding to the pivot scale k_*=0.002/Mpc is around 50. These results are marginally consistent with the fitting of the three-year Wilkinson microwave anisotropy probe data by the standard power-law cosmological model with cold dark matter and a cosmological constant. However, n_s can be reduced by applying two mechanisms: (i) The utilization of a quasi-canonical Kahler potential with a convenient choice of a sign and (ii) the restriction of the number of e-foldings that k_* suffered during FHI. In the case (i), we investigate the possible reduction of n_s without generating maxima and minima of the potential on the inflationary path. In the case (ii), the additional e-foldings required for solving the horizon and flatness problems can be generated by a subsequent stage of fast-roll [slow-roll] modular inflation realized by a string modulus which does [does not] acquire effective mass before the onset of modular inflation.

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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