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Although the cosmic microwave background (CMB) is largely understood to be homogeneous and isotropic, the CMB angular power spectra present anomalies that seem to break down parity symmetry at large angular scales. We argue that the…

General Relativity and Quantum Cosmology · Physics 2024-11-12 K. Sravan Kumar , João Marto

In this paper, we present compelling evidence for the parity asymmetry (a discrete symmetry that is separate from isotropy) in the Cosmic Microwave Background (CMB) map, measured through two-point temperature correlations. This parity…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-07 Enrique Gaztañaga , K. Sravan Kumar

The temperature fluctuations of the Cosmic Microwave Background (CMB) are supposed to be distributed randomly in both magnitude and phase, following to the simplest model of inflation. In this paper, we look at the odd and even multipoles…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 M. Hansen , A. M. Frejsel , J. Kim , P. Naselsky , F. Nesti

We extend the curvaton scenario presented by Erickcek et al. (2008, 2009), to explain how the even-odd multipole asymmetry of the Cosmic Microwave Background (CMB) (also called parity asymmetry, (Kim & Naselsky 2010)) and power anisotropies…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-29 Hao Liu , Anne Mette Frejsel , Pavel Naselsky

We argue that the anomalous power asymmetry observed in the cosmic microwave background (CMB) may have originated in a cosmic bounce preceding inflation. In loop quantum cosmology (LQC) the big bang singularity is generically replaced by a…

General Relativity and Quantum Cosmology · Physics 2015-09-30 Ivan Agullo

We investigate the cosmic microwave background (CMB) bispectra of the intensity (temperature) and polarization modes induced by the graviton non-Gaussianities, which arise from the parity-conserving and parity-violating Weyl cubic terms…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-14 Maresuke Shiraishi , Daisuke Nitta , Shuichiro Yokoyama

Noncommutative geometry can provide effective description of physics at very short distances taking into account generic effects of quantum gravity. Inflation amplifies tiny quantum fluctuations in the early universe to macroscopic scales…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Tomi S. Koivisto , David F. Mota

We study the reconstruction of the cosmic rotation power spectrum produced by parity-violating physics, with an eye to ongoing and near future cosmic microwave background (CMB) experiments such as BICEP Array, CMBS4, LiteBIRD and Simons…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-27 Toshiya Namikawa

The presence of CMB Hemispherical Asymmetry (HPA) challenges the current understanding of inflationary cosmology which does not generically predict the parity violation in the primordial correlations. In this paper, we shall review the…

High Energy Physics - Theory · Physics 2023-05-11 K. Sravan Kumar , João Marto

The standard cosmological model, which assumes statistical isotropy and parity invariance, predicts the absence of correlations between even-parity and odd-parity observables of the cosmic microwave background (CMB). Contrary to these…

We investigate the hemispherical power asymmetry observed in the CMBR by attributing it to an early inhomogeneous phase of cosmic expansion. Unlike the conventional assumption of a perfectly isotropic and homogeneous pre-inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-30 Akash Gandhi , Mohit Panwar , Pankaj Jain

We explore a model of the early universe in which the inflationary epoch is preceded by a cosmic bounce, and argue that this scenario provides a common origin to several of the anomalous features that have been observed at large angular…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-17 Ivan Agullo , Dimitrios Kranas , V. Sreenath

Given an arbitrary function, we may construct symmetric and antisymmetric functions under a certain operation. Since statistical isotropy and homogeneity of our Universe has been a fundamental assumption of modern cosmology, we do not…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-23 Jaiseung Kim , Pavel Naselsky , Martin Hansen

Context. The existence of a maximum correlation angle ($\theta_{max} \gtrsim 60^{\circ}$) in the two-point angular temperature correlations of cosmic microwave background (CMB) radiation, measured by WMAP and Planck, stands in sharp…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-27 M. -A. Sanchis-Lozano , F. Melia , M. López-Corredoira , N. Sanchis-Gual

We study the inflation process of universe based on the renormalizable quantum gravity formulated as a conformal field theory (CFT). We show that the power-law CFT spectrum approaches to that of the Harrison-Zel'dovich-Peebles type as the…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-18 Ken-ji Hamada , Shinichi Horata , Tetsuyuki Yukawa

Parity violation found in the Cosmic Microwave Background (CMB) radiation is a crucial clue for the non-standard cosmological model or the possible contamination of various foreground residuals and/or calibration of the CMB data sets. In…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-22 P. Naselsky , W. Zhao , J. Kim , S. Chen

If the inflaton is a pseudoscalar, then it naturally interacts with gauge fields via an axion-like coupling to $F_{\mu\nu} \tilde{F}^{\mu\nu}$. Through this coupling, the rolling inflaton produces quanta of the gauge field, that in their…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Lorenzo Sorbo

Under the existence of chiral non-Gaussian sources during inflation, the trispectrum of primordial curvature perturbations can break parity. We examine signatures of the induced trispectrum of the cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-06 Maresuke Shiraishi

Quantum field theory, which is generally used to describe the origin of large-scale gravitational perturbations during cosmic inflation, has been shown to omit an important physical effect in curved space-time, the nonlocal entanglement…

General Relativity and Quantum Cosmology · Physics 2022-04-01 Craig Hogan

We study the parity violation in the cosmic microwave background (CMB) bispectrum induced by primordial magnetic fields (PMFs). Deriving a general formula for the CMB bispectrum generated from not only non-helical but also helical PMFs, we…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-12 Maresuke Shiraishi
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