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Related papers: Primordial tensor bispectra in $\mu$-CMB cross-cor…

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If the seed magnetic fields exist in the early Universe, tensor components of their anisotropic stresses are not compensated prior to neutrino decoupling and the tensor metric perturbations generated from them survive passively.…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-10 Maresuke Shiraishi , Daisuke Nitta , Shuichiro Yokoyama , Kiyotomo Ichiki , Keitaro Takahashi

We examine the potential of polarization bispectra of the cosmic microwave background (CMB) to constrain primordial magnetic fields (PMFs). We compute all possible bispectra between temperature and polarization anisotropies sourced by PMFs…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-07 Maresuke Shiraishi

We develop a scenario of inflation with spontaneously broken time and space diffeomorphisms, with distinctive features for the primordial tensor modes. Inflationary tensor fluctuations are non adiabatic, and can acquire a mass during the…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-21 Angelo Ricciardone , Gianmassimo Tasinato

We explore possible non-Gaussian features of primordial gravitational waves by constructing model-independent templates for nonlinearity parameters of tensor bispectrum. Our analysis is based on Effective Field Theory of inflation that…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-16 Abhishek Naskar , Supratik Pal

We compute the fully non-linear Cosmic Microwave Background (CMB) anisotropies on scales larger than the horizon at last-scattering in terms of only the curvature perturbation, providing a generalization of the linear Sachs-Wolfe effect at…

Astrophysics · Physics 2009-11-13 N. Bartolo , S. Matarrese , A. Riotto

The temperature and polarization anisotropies of the Cosmic Microwave Background are analyzed under the hypothesis that the same inflationary seed accounting for protogalactic magnetism also affects the Einstein-Boltzmann hierarchy whose…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-02 Massimo Giovannini

We propose and develop a formalism to describe and constrain statistically anisotropic primordial perturbations. Starting from a decomposition of the primordial power spectrum in spherical harmonics, we find how the temperature fluctuations…

Astrophysics · Physics 2009-11-13 C. Armendariz-Picon

We investigate parity-violating signatures of temperature and polarization bispectra of the cosmic microwave background (CMB) in an inflationary model where a rolling pseudoscalar produces large equilateral tensor non-Gaussianity. By a…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-22 Maresuke Shiraishi , Angelo Ricciardone , Shohei Saga

Cosmic Microwave Background (CMB) Anisotropies is a subject of intensive research in several fields of sciences. In this paper we start a systematic development of basic notions and theory in statistics according to the application for CMB.…

Applications · Statistics 2013-12-30 Gyorgy Terdik

It is well known that CMB temperature anisotropies and polarization can be used to probe the metric perturbations in the early universe. Presently, there exist neither any observational detection of tensor modes of primordial metric…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-23 Gaurav Goswami , Jayanti Prasad

Distortions of the Cosmic Microwave Background energy spectrum of the $\mu$ type are sensitive to the primordial power spectrum through the dissipation of curvature perturbations on scales $k\simeq 50$ - $10^4\,\mathrm{Mpc}^{-1}$. Their…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Giovanni Cabass , Enrico Pajer , Drian van der Woude

We develop a possibility of generating tensor non-Gaussianity in a kind of anisotropic inflation, where a $U(1)$ gauge field is kinetically coupled to a spectator scalar field. Owing to this coupling, the coherent mode of the electric field…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 Takashi Hiramatsu , Kai Murai , Ippei Obata , Shuichiro Yokoyama

Single field inflationary models that seek to greatly enhance small scale power in order to form primordial black holes predict both a squeezed bispectrum that is enhanced by this small scale power and a potentially detectable enhancement…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-08 David Zegeye , Keisuke Inomata , Wayne Hu

Spatially fluctuating primordial magnetic fields (PMFs) inhomogeneously reheat the Universe when they dissipate deep inside the horizon before recombination. Such an energy injection turns into an additional photon temperature perturbation.…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-28 Shohei Saga , Atsuhisa Ota , Hiroyuki Tashiro , Shuichiro Yokoyama

In this paper, we study the amplification of weak frequency dependent signals in the CMB sky due to their cross correlation to intrinsic anisotropies. In particular, we center our attention on mechanisms generating some weak signal, of…

Astrophysics · Physics 2009-09-29 C. Hernandez-Monteagudo , R. A. Sunyaev , MPA , IKI

We review in a pedagogical way the present status of the impact of non-Gaussianity (NG) on the Cosmic Microwave Background (CMB) anisotropies. We first show how to set the initial conditions at second-order for the (gauge invariant) CMB…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 N. Bartolo , S. Matarrese , A. Riotto

We consider the hypothesis that nonlocal, omnidirectional, causally-coherent quantum entanglement of inflationary horizons may account for some well-known measured anomalies of Cosmic Microwave Background (CMB) anisotropy on large angular…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Craig Hogan , Stephan S. Meyer

The bispectrum of the cosmic microwave background (CMB) generated by a correlation between a time-dependent gravitational potential and the weak gravitational lensing effect provides a direct measurement of the influence of dark energy on…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Veronika Junk , Eiichiro Komatsu

The BICEP2 collaboration reports a detection of primordial cosmic microwave background (CMB) B-mode with a tensor-scalar ratio $r=0.20^{+0.07}_{-0.05}$ (68% C.L.). However, this result is in tension with the recent Planck limit, $r<0.11$…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-30 Jun-Qing Xia , Yi-Fu Cai , Hong Li , Xinmin Zhang

We examine the extent to which galactic and extragalactic foregrounds can hamper the detection of primordial Cosmic Microwave Background (CMB) anisotropies. We limit our discussion to intermediate angular scales, $10^{\prime}\lsim \theta…

Astrophysics · Physics 2009-09-25 L. Toffolatti
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