A Truncated Primordial Power Spectrum and Its Impact on B-Mode Polarization

التفاصيل البيبلوغرافية
العنوان: A Truncated Primordial Power Spectrum and Its Impact on B-Mode Polarization
المؤلفون: Liu, Jingwei, Melia, Fulvio
سنة النشر: 2024
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Cosmology and Nongalactic Astrophysics
الوصف: The absence of large-angle correlations in the temperature of the cosmic microwave background (CMB), confirmed by three independent satellite missions, creates significant tension with the standard model of cosmology. Previous work has shown, however, that a truncation, $k_{min}$, of the primordial power spectrum comprehensively resolves the anomaly and the missing power at $\ell\lesssim 5$ (the low multipoles). Since this cutoff is consistent with the hypothesized delay of inflation well beyond the Planck time, we are strongly motivated to consider its possible impact on other observational signatures. In this Letter, we analyze and predict its influence on the most revealing probe awaiting measurement by upcoming missions -- the B-mode polarization of the CMB, whose accurate determination should greatly impact the inflationary picture. We highlight the quantitative power of this discriminant by specifically considering the LiteBIRD mission, predicting the effect of $k_{min}$ on both the angular power spectrum and the angular correlation function of the B-mode, for a range of tensor-to-scalar ratios, $r$. While its impact on the latter appears to be negligible, $k_{\rm min}$ should have a very pronounced effect on the former. We show that for $r=0.036$, $k_{min}$'s impact on $C_{\ell}^{BB}$ at low $\ell$'s should be easily detectable by LiteBIRD, but will be largely hidden by the total uncertainty of the measurement if $r\lesssim 0.02$.
Comment: 8 pages, 6 figures. Accepted for publication in PLB
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2404.08170
رقم الأكسشن: edsarx.2404.08170
قاعدة البيانات: arXiv