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Related papers: The Open Universe Grishchuk-Zel'dovich Effect

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We calculate the gravitational wave background produced from density perturbations in an early matter domination era where primordial black holes form. The formation of black holes requires perturbations out of the linear regime. Space with…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-04 Ioannis Dalianis , Chris Kouvaris

The Sunyaev-Zeldovich (SZ) effect is a promising tool for detecting the presence of hot gas out to the galaxy cluster peripheries. We developed a spectral imaging algorithm dedicated to the SZ observations of nearby galaxy clusters with…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-26 H. Bourdin , P. Mazzotta , E. Rasia

We investigate the dominant physical effects of superhorizon fluctuations in a flat FLRW universe, focusing on whether the combined evolution of scalar and tensor adiabatic modes in the near-horizon regime could lead to geometries beyond…

General Relativity and Quantum Cosmology · Physics 2025-04-02 Jorge Noreña , Thiago S. Pereira , Sean K. Reynolds

Recently, an anisotropic cosmological model was proposed. An arbitrary 1-form, which picks out a privileged axis in the universe, was added to the Friedmann-Robertson-Walker line element. The distance-redshift relation was modified such…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-14 Zhe Chang , Xin Li , Hai-Nan Lin , Sai Wang

We consider five dimensional conformal gravity theory which describes an anisotropic extra dimension. Reducing the theory to four dimensions yields Brans-Dicke theory with a potential and a hidden parameter $z$ which implements the…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-23 Seyen Kouwn , Phillial Oh , Chan-Gyung Park

It is shown that a first-order cosmological perturbation theory for the open, flat and closed Friedmann-Lema\^itre-Robertson-Walker universes admits one, and only one, gauge-invariant variable which describes the perturbation to the energy…

General Relativity and Quantum Cosmology · Physics 2014-10-02 P. G. Miedema , W. A. van Leeuwen

Peculiar velocities in the nearby Universe can be measured via the kinetic Sunyaev-Zel'dovich (kSZ) effect. Using a statistical method based on an optimised cross-correlation with nearby galaxies, we extract the kSZ signal generated by…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Guilhem Lavaux , Niayesh Afshordi , Michael J. Hudson

Affleck-Dine (AD) baryogenesis can produce the baryon asymmetry of the Universe through the $CP$-violating dynamics of AD field. The field generally fragments into Q-balls, whose rapid decay induces enhanced gravitational waves. In this…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-11 Yan-Heng Yu , Sai Wang

We discuss the kinetic Sunyaev-Zel'dovich (SZ) contribution to cosmic microwave background (CMB) temperature fluctuations due to coherent rotational velocity component of electrons within halos. This effect produces a distinct dipole-like…

Astrophysics · Physics 2009-11-07 Asantha Cooray , Xuelei Chen

We present a new derivation of the cosmic microwave background anisotropy spectrum from the Ostriker-Vishniac effect for an open, flat, or closed Universe, and calculate the anisotropy expected in cold dark-matter (CDM) models. We provide…

Astrophysics · Physics 2016-08-25 A. H. Jaffe , M. Kamionkowski

We discuss how the space of possible cosmological parameters is constrained by the angular diameter distance function, D_A(z), as measured using the SZ/X-ray method which combines Sunyaev-Zel'dovich (SZ) effect and X-ray brightness data for…

Astrophysics · Physics 2009-11-07 S. M. Molnar , M. Birkinshaw , R. F. Mushotzky

We have surveyed two science fields totaling one square degree with Bolocam at 2.1 mm to search for secondary CMB anisotropies caused by the Sunyaev- Zel'dovich effect (SZE). The fields are in the Lynx and Subaru/XMM SDS1 fields. Our survey…

We use an analytic model to investigate the theoretical uncertainty on the thermal Sunyaev-Zel'dovich (SZ) power spectrum due to astrophysical uncertainties in the thermal structure of the intracluster medium. Our model accounts for star…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Laurie D. Shaw , Daisuke Nagai , Suman Bhattacharya , Erwin T. Lau

The kinetic Sunyaev Zel'dovich (kSZ) effect, cosmic microwave background (CMB) anisotropies induced by scattering from free electrons in bulk motion, is a primary target of future CMB experiments. Measurements of the kSZ effect have the…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-12 Juan I. Cayuso , Matthew C. Johnson , James B. Mertens

We analyze the propagation of gravitational waves in a medium containing bounded subsystems ("molecules"), able to induce significant Macroscopic Gravity effects. We establish a precise constitutive relation between the average quadrupole…

General Relativity and Quantum Cosmology · Physics 2019-07-26 Giovanni Montani , Fabio Moretti

A future detection of the Stochastic Gravitational Wave Background (SGWB) with GW experiments is expected to open a new window on early universe cosmology and on the astrophysics of compact objects. In this paper we study SGWB anisotropies,…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-22 N. Bartolo , D. Bertacca , S. Matarrese , M. Peloso , A. Ricciardone , A. Riotto , G. Tasinato

Induced gravitational waves provide a powerful probe of primordial perturbations in the early universe through their distinctive spectral properties. We analyze the spectral energy density $\Omega_{\text{GW}}$ of gravitational waves induced…

General Relativity and Quantum Cosmology · Physics 2025-01-20 Chang Han , Zu-Cheng Chen , Hongwei Yu , Puxun Wu

The recent discovery of two flux decrements in deep radio maps obtained by the VLA and the Ryle Telescope can have powerful implications for the density parameter of the Universe, $\Omo$. We outline these implications by modeling the…

Astrophysics · Physics 2007-05-23 J. G. Bartlett , A. Blanchard , D. Barbosa

The Stochastic Gravitational Wave Background (SGWB) is expected to be a key observable for Gravitational Wave (GW) interferometry. Its detection will open a new window on early universe cosmology and on the astrophysics of compact objects.…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-11 N. Bartolo , D. Bertacca , S. Matarrese , M. Peloso , A. Ricciardone , A. Riotto , G. Tasinato

We study perturbation theory for large-scale structure in the most general scalar-tensor theories propagating a single scalar degree of freedom, which include Horndeski theories and beyond. We model the parameter space using the effective…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-09 Marco Crisostomi , Matthew Lewandowski , Filippo Vernizzi