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Related papers: Tensor Anisotropies in an Open Universe

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We propose a Lambda-inflation model which explains a significant part of the COBE signal by primordial cosmic gravitational waves. The primordial density perturbations fulfill both the constraints of large-scale microwave background and…

Astrophysics · Physics 2011-07-19 V. N. Lukash , E. V. Mikheeva , V. Muller , A. M. Malinovsky

Phase transitions in the early universe can readily create an observable stochastic gravitational wave background. We show that such a background necessarily contains anisotropies analogous to those of the cosmic microwave background (CMB)…

High Energy Physics - Phenomenology · Physics 2019-08-06 Michael Geller , Anson Hook , Raman Sundrum , Yuhsin Tsai

Cosmic microwave background (CMB) temperature anisotropies have and will continue to revolutionize our understanding of cosmology. The recent discovery of the previously predicted acoustic peaks in the power spectrum has established a…

Astrophysics · Physics 2011-07-19 Wayne Hu , Scott Dodelson

We investigate the dependence of large angular scale cosmic microwave background anisotropies on various initial conditions, including both adiabatic and isocurvature perturbations and the initial power law index $n$, in a variety of…

Astrophysics · Physics 2009-10-22 Naoshi Sugiyama , Joseph Silk

An important prediction of inflation is the production of a primordial stochastic gravitational wave background. Observing this background is challenging due to the weakness of the signal and the simultaneous presence of an astrophysical…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 Sofia P. Corbà

These lecture notes cover mainly three connected topics. In the first part we give a detailed treatment of cosmological perturbation theory. The second part is devoted to cosmological inflation and the generation of primordial fluctuations.…

High Energy Physics - Phenomenology · Physics 2009-11-11 Norbert Straumann

We propose a $\Lambda$-inflation model which explains a large fraction of the COBE signal by cosmic gravitational waves. The primordial density perturbations fulfil both the contraints of large-scale microwave background and galaxy cluster…

Astrophysics · Physics 2011-07-19 V. N. Lukash , E. V. Mikheeva , V. Müller , A. M. Malinovsky

We study the microwave background anisotropy due to superhorizon-size perturbations (the Grischuk-Zel'dovich effect) in open universes with negative spatial curvature. Using COBE results on the low-order temperature multipole moments, we…

Astrophysics · Physics 2009-10-22 A. Kashlinsky , I. I. Tkachev , J. Frieman

A brief account is given of large-scale structure modelling based on the assumption that the initial perturbations arise from inflation. A recap is made of the implications of inflation for large-scale structure; under the widely applicable…

Astrophysics · Physics 2007-05-23 Andrew R Liddle

Contributions of primordial gravitational waves to the large-angular-scale anisotropies of the cosmic microwave background radiation in multidimensional cosmological models (Kaluza-Klein models) are studied. We derive limits on free…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Yuri Kubyshin , Jerome Martin

We study the imprints of anisotropic inflation on the CMB temperature fluctuations and polarizations. The statistical anisotropy stems not only from the direction dependence of curvature and tensor perturbations, but also from the cross…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-23 Masa-aki Watanabe , Sugumi Kanno , Jiro Soda

In principle, the tensor metric (gravity-wave) perturbations that arise in inflationary models can, beyond probing the underlying inflationary model, provide information about the Universe: ionization history, presence of a cosmological…

Astrophysics · Physics 2009-08-18 Michael S. Turner , Martin White , James E. Lidsey

We discuss the cosmological evolution of matter sources with small anisotropic pressures. This includes electric and magnetic fields, collisionless relativistic particles, gravitons, antisymmetric axion fields in low-energy string…

General Relativity and Quantum Cosmology · Physics 2007-05-23 John D. Barrow

We analyse the implications for inflationary models of the cosmic microwave background (cmb) anisotropy measured by COBE. Vacuum fluctuations during inflation generate an adiabatic density perturbation, and also gravitational waves. The…

Astrophysics · Physics 2009-10-22 David H Lyth , Andrew R Liddle

Could COBE DMR be detecting the imprint from a spectrum of gravitational waves generated during inflation? The conventional inflationary prediction had been that the cosmic microwave anisotropy is dominated by energy density fluctuations…

Astrophysics · Physics 2009-09-15 George F. Smoot , Paul J. Steinhardt

The primordial Universe can be used as a laboratory to set constraints on quantum gravity. In the framework of Loop Quantum Cosmology, we show that such a proposal for quantum gravity not only solves for the big bang singularity issue but…

General Relativity and Quantum Cosmology · Physics 2012-06-08 Julien Grain

The genuine quantum gravity effects can already be around us. It is likely that the observed large-angular-scale anisotropies in the microwave background radiation are induced by cosmological perturbations of quantum-mechanical origin. Such…

General Relativity and Quantum Cosmology · Physics 2007-05-23 L. P. Grishchuk

We expose the scenarios of primordial baryon-photon plasma evolution within the framework of the Milne-like universe models. Recently, such models find a second wind and promise an inflation-free solution of a lot of cosmological puzzles…

General Relativity and Quantum Cosmology · Physics 2019-01-09 S. L. Cherkas , V. L. Kalashnikov

It is shown that rotational cosmological perturbations can be generated in the early Universe, similarly to gravitational waves. The generating mechanism is quantum-mechanical in its nature, and the created perturbations should now be…

General Relativity and Quantum Cosmology · Physics 2010-11-19 L. P. Grishchuk

The anisotropy and polarization of the cosmic microwave background radiation (CMBR) induced by the scalar and tensor metric perturbations are computed in the long-wavelength limit. It is found that the large-scale polarization of CMBR…

Astrophysics · Physics 2009-10-22 Ka Lok Ng , Kin-Wang Ng