Anomalies in the CMB from a cosmic bounce

Cosmic Tango Between the Very Small and the Very Large: Addressing CMB Anomalies Through Loop Quantum Cosmology

“…Although these modes are not in the observable range for CMB, it is of interest to better understand the origin of this growth in power for very small k because, together with large and strongly scale dependent non-Gaussianity (which is expected from the LQC bounce (Agullo et al, 2018;Sreenath et al, 2019) it could lead to a coupling between the long wavelength modes and the modes observable in CMB, resulting in a modulation of the primordial power spectrum of the observable modes. Such a non-Gaussian modulation could explain the dipolar modulation of CMB and preference for odd parity that has been observed in the CMB (Agullo et al, 2021a;Agullo et al, 2021b).…”

“…Therefore, one can hope to meaningfully extend the standard inflationary paradigm to the Planck regime. Over the past decade, several closely related approaches have been used to carry out this task, leading to a striking interplay between theory and observations [see, in particular Agullo et al (2012), Agullo et al (2013a), Agullo et al (2013b), Fernandez-Mendez et al (2012), Barrau et al (2014), Linsefors et al (2013), Ashtekar and Barrau (2015), Agullo and Morris (2015), Agullo (2015), Ashtekar and Gupt (2017a), Ashtekar and Gupt (2017b), Gomar et al (2017), Agullo et al (2018), Barrau et al (2018), Agullo et al (2020a), Agullo et al (2020b), Sreenath et al (2019), Agullo et al (2021a), Agullo et al (2021b)]. In this article we will focus on the recent results that shed new light on the anomalous features seen in the cosmic microwave background (CMB).…”

Cosmic tango between the very small and the very large: Addressing CMB anomalies through Loop Quantum Cosmology

“…Therefore, one can hope to meaningfully extend the standard inflationary paradigm to the Planck regime. Over the past decade, several closely related approaches have been used to carry out this task, leading to a striking interplay between theory and observations (see, in particular, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]). In this article we will focus on the recent results that shed new light on the anomalous features seen in the cosmic microwave background (CMB).…”

Anomalies in the Cosmic Microwave Background and Their Non-Gaussian Origin in Loop Quantum Cosmology

“…In recent work (Agullo et al, 2021a;Agullo et al, 2021b) we proposed that a cosmic bounce before inflation naturally changes the primordial probability distribution in such a way that, in a statistical sense, the observed features are not anomalous. The core of the idea is that a cosmic bounce generates strong correlations (non-Gaussianities) between the longest modes we observe in the sky and longer, super-horizon modes.…”

“…But these correlations produce indirect effects in observable modes, which can account for the observed anomalies. The goal of this article is to apply the general ideas introduced in (Agullo et al, 2021a;Agullo et al, 2021b) to LQC. We will also take the opportunity to provide a succinct and pedagogical introduction to CMB anomalies and the phenomenon of non-Gaussian modulation, addressed to the quantum cosmology community.…”