arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1202.2852astro-ph.COgr-qchep-ph
收藏

唯象和双场暴胀模型中标量和张量扰动的约束：原始等曲率和张量模的贝叶斯证据

Constraints on scalar and tensor perturbations in phenomenological and two-field inflation models: Bayesian evidences for primordial isocurvature and tensor modes

Jussi Valiviita, Matti Savelainen, Marianne Talvitie, Hannu Kurki-Suonio, Stanislav Rusak

备注：
30 pages, 18 figures
发表信息：
Astrophys.J. 753 (2012) 151
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

我们约束宇宙学模型的原始扰动既有绝热和（可能相关）冷暗物质（CDM）或重子等曲率组件。我们使用一个唯象的方法，其中的原始功率谱参数化的振幅和光谱指数，和一个慢卷两个字段的通货膨胀的方法，其中慢卷参数作为主要参数。在唯象的情况下，利用CMB数据，CDM等曲率分数的上限在k=0.002Mpc^{-1}时为α<6.4%，在k=0.01Mpc^{-1}时为15.4%。对于CMB温度变化的非绝热贡献的中值95%范围为-0.030<α_T<0.049。包括超新星（或大尺度结构，LSS）数据，这些限制为：α<7.0%，13.7%，和-0.048<α_T< 0.042（或α<10.2%，16.0%，和-0.071<α_T<0.024）。在k=0.01Mpc^{-1}时，CMB对张量标量比的约束r<0.26，不受非绝热模的影响。在慢滚双场暴胀方法中，谱指数被限制为接近1。这导致对等曲率分数的更严格限制，在k=0.01Mpc^{-1}时CMB数据α<2.6%，但对α_T的约束没有太大影响，-0.058<α_T<0.045。包括SN（或LSS）数据，这些限值变为：α< 3.2%和-0.056<α_T<0.030（或α<3.4%和-0.063<α_T<-0.008）。当所有谱指数彼此接近时，等曲率分数随张量标量比而有些退化。除了一般的相关模型，我们还研究了特殊情况下，扰动模式是不相关的或完全（反）相关的。我们计算贝叶斯证据（模型概率）在21个不同的情况下，我们的非绝热模型和相应的绝热模型，并发现在所有情况下的数据支持纯绝热模型。

英文摘要：

We constrain cosmological models where the primordial perturbations have both an adiabatic and a (possibly correlated) cold dark matter (CDM) or baryon isocurvature component. We use both a phenomenological approach, where the primordial power spectra are parametrized with amplitudes and spectral indices, and a slow-roll two-field inflation approach where slow-roll parameters are used as primary parameters. In the phenomenological case, with CMB data, the upper limit to the CDM isocurvature fraction is α<6.4% at k=0.002Mpc^{-1} and 15.4% at k=0.01Mpc^{-1}. The median 95% range for the non-adiabatic contribution to the CMB temperature variance is -0.030<α_T<0.049. Including the supernova (or large-scale structure, LSS) data, these limits become: α<7.0%, 13.7%, and -0.048<α_T< 0.042 (or α<10.2%, 16.0%, and -0.071<α_T<0.024). The CMB constraint on the tensor-to-scalar ratio, r<0.26 at k=0.01Mpc^{-1}, is not affected by the nonadiabatic modes. In the slow-roll two-field inflation approach, the spectral indices are constrained close to 1. This leads to tighter limits on the isocurvature fraction, with the CMB data α<2.6% at k=0.01Mpc^{-1}, but the constraint on α_T is not much affected, -0.058<α_T<0.045. Including SN (or LSS) data, these limits become: α< 3.2% and -0.056<α_T<0.030 (or α<3.4% and -0.063<α_T<-0.008). When all spectral indices are close to each other the isocurvature fraction is somewhat degenerate with the tensor-to-scalar ratio. In addition to the generally correlated models, we study also special cases where the perturbation modes are uncorrelated or fully (anti)correlated. We calculate Bayesian evidences (model probabilities) in 21 different cases for our nonadiabatic models and for the corresponding adiabatic models, and find that in all cases the data support the pure adiabatic model.

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。

↑