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Related papers: Compensated Isocurvature Perturbations and the Cos…

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Compensated isocurvature perturbations (CIPs) are primordial fluctuations that balance baryon and dark-matter isocurvature to leave the total matter density unperturbed. The effects of CIPs on the cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-18 Tristan L. Smith , Julian B. Muñoz , Rhiannon Smith , Kyle Yee , Daniel Grin

In the standard inflationary scenario, primordial perturbations are adiabatic. The amplitudes of most types of isocurvature perturbations are generally constrained by current data to be small. If, however, there is a baryon-density…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-24 Julian B. Muñoz , Daniel Grin , Liang Dai , Marc Kamionkowski , Ely D. Kovetz

Primordial fluctuations in the relative number densities of particles, or isocurvature perturbations, are generally well constrained by cosmic microwave background (CMB) data. A less probed mode is the compensated isocurvature perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-30 Chen He , Daniel Grin , Wayne Hu

Baryon-density perturbations of large amplitude may exist if they are compensated by dark-matter perturbations so that the total density remains unchanged. Big-bang nucleosynthesis and galaxy clusters allow the amplitudes of these…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-09 Daniel Grin , Olivier Doré , Marc Kamionkowski

Compensated isocurvature perturbations (CIPs) are modes in which the baryon and dark matter density fluctuations cancel. They arise in the curvaton scenario as well as some models of baryogenesis. While they leave no observable effects on…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 Chen He Heinrich , Daniel Grin , Wayne Hu

Compensated isocurvature perturbations are opposite spatial fluctuations in the baryon and dark matter (DM) densities. They arise in the curvaton model and some models of baryogenesis. While the gravitational effects of baryon fluctuations…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-24 Chen Heinrich

Primordial isocurvature fluctuations between photons and either neutrinos or non-relativistic species such as baryons or dark matter are known to be sub-dominant to adiabatic fluctuations. Perturbations in the relative densities of baryons…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-22 Daniel Grin , Duncan Hanson , Gilbert Holder , Olivier Doré , Marc Kamionkowski

Compensated isocurvature perturbations (CIPs) are opposite spatial fluctuations in the baryon and dark matter density. They can be generated for example in the curvaton model in the early Universe but are difficult to observe because their…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-04 Chen Heinrich , Marcel Schmittfull

We develop a linear perturbation theory for the spectral $y$-distortions of the cosmic microwave background (CMB). The $y$-distortions generated during the recombination epoch are usually negligible because the energy transfer due to the…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-10 Taku Haga , Keisuke Inomata , Atsuhisa Ota , Andrea Ravenni

The Cosmic Microwave Background Radiation (CMB) is an invaluable probe of the conditions of the early universe. Recent measurements of its spatial anisotropy have allowed accurate determinations of several fundamental cosmological…

Astrophysics · Physics 2009-09-29 Christopher O'Dell

Compensated isocurvature perturbations (CIPs) are relative density perturbations in which a baryon-density fluctuation is accompanied by a dark matter density fluctuation such that the total-matter density is unperturbed. These fluctuations…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Neha Anil Kumar , Selim C. Hotinli , Marc Kamionkowski

Compensated isocurvature perturbations (CIPs) are modulations of the relative baryon and dark matter density that leave the total matter density constant. The best current constraints from the primary cosmic microwave background (CMB) are…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-04 Selim C. Hotinli , James B. Mertens , Matthew C. Johnson , Marc Kamionkowski

The Universe's initial conditions, in particular baryon and cold dark matter (CDM) isocurvature perturbations, are poorly constrained on sub-Mpc scales. In this paper, we develop a new formalism to compute the effect of small-scale baryon…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-24 Nanoom Lee , Yacine Ali-Haïmoud

We investigate the potential of the galaxy power spectrum to constrain compensated isocurvature perturbations (CIPs), primordial fluctuations in the baryon density that are compensated by fluctuations in CDM density to ensure an unperturbed…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-22 Alexandre Barreira , Giovanni Cabass , Kaloian D. Lozanov , Fabian Schmidt

The analysis of anisotropies in the cosmic microwave background (CMB) has become an extremely valuable tool for cosmology. We even have hopes that planned CMB anisotropy experiments may revolutionize cosmology. Together with determinations…

Astrophysics · Physics 2011-04-15 Ruth Durrer

Dark matter comprised of axion-like particles (ALPs) generated by the realignment mechanism in the post-inflationary scenario leads to primordial isocurvature fluctuations. The power spectrum of these fluctuations is flat for small wave…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-09 Martin Feix , Steffen Hagstotz , Andreas Pargner , Robert Reischke , Bjoern Malte Schaefer , Thomas Schwetz

We examine bounds on adiabatic and isocurvature density fluctuations from $\mu$-type spectral distortions of the cosmic microwave background (CMB). Studies of such distortion are complementary to CMB measurements of the spectral index and…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 James B. Dent , Damien A. Easson , Hiroyuki Tashiro

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

Astrophysics · Physics 2009-11-06 Masahiro Kawasaki , Takeo Moroi , Tomo Takahashi

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

Astrophysics · Physics 2007-05-23 Tomo Takahashi

Cosmic birefringence$-$the rotation of the polarization plane of light as it traverses the universe$-$offers a direct observational window into parity-violating physics beyond the Standard Model. In this work, we revisit the anisotropic…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-27 A. I. Lonappan , B. Keating , K. Arnold
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