English
Related papers

Related papers: Limits on the gravity wave contribution to microwa…

200 papers

We assess the relative contribution to the COBE - measured microwave anisotropy arising both from relic gravity waves as well as primordial density perturbations originating during inflation. We show that the gravity wave contribution to…

High Energy Physics - Phenomenology · Physics 2007-05-23 Varun Sahni , Tarun Souradeep

We investigate the anisotropies in the cosmic microwave background in a class of models which possess a positive cosmic energy density but negative pressure, with a constant equation of state w = p/rho < -1. We calculate the temperature and…

Astrophysics · Physics 2009-07-09 A. E. Schulz , Martin White

Comparison of theobservedanisotropy with that predicted iadiabaticDM models suggest that much of thserved signal may be due to long wavelenh gravitational waves. In inflationary models this requires the generation of tensor fluctuations to…

High Energy Physics - Phenomenology · Physics 2007-05-23 Lawrence M. Krauss

We calculate the anisotropies in the cosmic microwave background induced by long-wavelength primordial gravitational waves in a universe with negative spatial curvature, such as are produced in the ``open inflation'' scenario. The impact of…

Astrophysics · Physics 2009-10-30 Wayne Hu , Martin White

Anisotropy of the cosmic microwave background radiation (CMB) originates from both tensor and scalar perturbations. To study the characteristics of each of these two kinds of perturbations, one has to determine the contribution of each to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. Ashoorioon , R. B. Mann

We explore constraints on inflationary models employing data on large scale structure mainly from COBE temperature anisotropies and IRAS selected galaxy surveys, taking care not to apply linear perturbation theory to data in the non-linear…

Astrophysics · Physics 2009-12-30 R. K. Schaefer , Q. Shafi

We show that in theories with a nontrivial kinetic term the contribution of the gravitational waves to the CMB fluctuations can be substantially larger than that is naively expected in simple inflationary models. This increase of the…

Astrophysics · Physics 2014-10-13 V. Mukhanov , A. Vikman

The nonlinear interaction between one graviton and two scalars is enhanced in specific inflationary models, potentially leading to distinguishable signatures in the bispectrum of the cosmic microwave background (CMB) anisotropies. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-15 Maresuke Shiraishi , Michele Liguori , James R. Fergusson

Solid inflation can support a long period of anisotropic inflation. We calculate the statistical anisotropies in the scalar and tensor power spectra and their cross-correlation in anisotropic solid inflation. The tensor-scalar…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Mohammad Akhshik , Razieh Emami , Hassan Firouzjahi , Yi Wang

Inflation produces nearly Harrison-Zel'dovich scalar and tensor perturbation spectra which lead to anisotropy in the cosmic microwave background (CMB). The amplitudes and shapes of these spectra can be parametrized by $Q_S^2$, $r\equiv…

Astrophysics · Physics 2009-10-28 Lloyd Knox

There are large classes of inflationary models, particularly popular in the context of string theory and brane world approaches to inflation, in which the ratio of linearized tensor to scalar metric fluctuations is very small. In such…

Astrophysics · Physics 2008-11-26 P. Martineau , R. Brandenberger

We investigate the possibility that the amplitude of scalar density perturbations may be damped after inflation. This would imply that CMB anisotropies do not uniquely fix the amplitude of the perturbations generated during inflation and…

Astrophysics · Physics 2009-11-11 N. Bartolo , Edward W. Kolb , A. Riotto

We calculate the spectrum of large angle cosmic microwave background (CMB) anisotropies due to quantum fluctuations of the gravitational wave modes in one-bubble open inflation models. We find the bubble-wall fluctuation modes, which had…

Astrophysics · Physics 2016-08-30 Misao Sasaki , Takahiro Tanaka , Yoshihiro Yakushige

It is commonly assumed that the stochastic background of gravitational waves on cosmological scales follows an almost scale-independent power spectrum, as generically predicted by the inflationary paradigm. However, it is not inconceivable…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-14 Jan Hamann , Ameek Malhotra

We derive power spectra of the scalar- and tensor-type structures generated in an inflation model based on a massive non-minimally coupled scalar field with the strong coupling assumption. We make analyses in both the original-frame and the…

Astrophysics · Physics 2009-12-30 J. Hwang , H. Noh

The measurement of B-mode polarization of the cosmic microwave background at large angular scales by the BICEP experiment suggests a stochastic gravitational wave background from early-universe inflation with a surprisingly large amplitude.…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-21 Jerod Caligiuri , Arthur Kosowsky

We explore a broad class of three-parameter inflationary models, called the $\Lambda$-inflation, and its observational predictions: high abundance of cosmic gravitational waves consistent with the Harrison-Zel'dovich spectrum of primordial…

Astrophysics · Physics 2016-12-28 V. N. Lukash , E. V. Mikheeva

In this paper, inflationary cosmology is reviewed, paying particular attention to its observational signatures associated with large-scale density perturbations generated from quantum fluctuations. In the most general scalar-tensor theories…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-13 Shinji Tsujikawa

We identify models of supersymmetric hybrid inflation in which the tensor-to-scalar ratio, a canonical measure of gravity waves produced during inflation, can be as large as 0.03 or so, which will be tested by the Planck satellite…

High Energy Physics - Phenomenology · Physics 2011-03-07 Qaisar Shafi , Joshua R. Wickman

The detection of Primordial Gravitational Waves (PGWs) is one of the most important goals of modern cosmology since PGWs can both provide substantial evidence for primordial inflation and shed light on its physical nature. Small scale…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-17 William Giarè , Alessandro Melchiorri