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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

It is plausible that the scalar density perturbations are created by a relatively low scale model of inflation which predicts the CMB anisotropy and excites Standard Model baryon and cold dark matter, but negligible gravity waves.…

Astrophysics · Physics 2008-04-03 Rouzbeh Allahverdi , Anupam Mazumdar , Tuomas Multamaki

We obtain mass limits on the extra neutral gauge boson which is predicted in a model with hidden gauge symmetry and dynamical breaking of the electroweak symmetry by a top quark condensate. For typical model assumptions, present LEP data…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ralf Bönisch , Arnd Leike

Detailed study of the scalar and tensor perturbation spectra can provide much information about the primordial fluctuation-generator, be it inflation or something else. The tensor perturbation spectrum may be observable through its…

Astrophysics · Physics 2007-05-23 L. Knox

The maximum size of a bound cosmic structure is computed perturbatively as a function of its mass in the framework of the cubic galileon, proposed recently to model the dark energy of our Universe. Comparison of our results with…

General Relativity and Quantum Cosmology · Physics 2016-05-20 Sourav Bhattacharya , Konstantinos F. Dialektopoulos , Theodore N. Tomaras

Observations of the Cosmic Microwave Background (CMB), large scale structure (LSS) and standard candles such as Type 1a Supernovae (SN) each place different constraints on the values of cosmological parameters. We assume an inflationary…

Astrophysics · Physics 2007-05-23 A. N. Lasenby , S. L. Bridle , M. P. Hobson

The possibility of determining cosmological parameters on the basis of a wide set of observational data including the Abell-ACO cluster power spectrum and mass function, peculiar velocities of galaxies, the distribution of Ly-$\alpha$…

Astrophysics · Physics 2007-05-23 B. Novosyadlyj , R. Durrer , S. Gottloeber , V. N. Lukash , S. Apunevych

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

We reexamine constraints on the spatial size of closed toroidal models with cold dark matter and the cosmological constant from cosmic microwave background. We carry out Bayesian analyses using the Cosmic Background Explorer (COBE) data…

Astrophysics · Physics 2009-11-07 Kaiki Taro Inoue , Naoshi Sugiyama

The energy scale of inflation is of much interest, as it suggests the scale of grand unified physics and also governs whether cosmological events such as topological defect formation can occur after inflation. The COBE results are used to…

Astrophysics · Physics 2010-11-01 Andrew R Liddle

In recent years, the detection of gravitational waves by LIGO and PTA collaborations have raised the intriguing possibility of excess matter power at small scales. Such an increase can be achieved by ultra slow roll (USR) phase during…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 H. V. Ragavendra , Anjan Kumar Sarkar , Shiv K. Sethi

Models for structure formation attempt to predict the power spectrum of density perturbations in the present universe from the initial power spectrum and the nature of dark matter. Observational constraints on the power spectrum at…

Astrophysics · Physics 2007-05-23 K. Subramanian , T. Padmanabhan

The COBE detection of microwave anisotropies provides the best way of fixing the amplitude of cosmological fluctuations on the largest scales. We discuss the impact of this new, precise normalization and give fitting formulae for the…

Astrophysics · Physics 2009-08-18 Martin White , Douglas Scott

We derive cosmological parameters from the CBI measurements of the Cosmic Microwave Background (CMB) angular power spectrum. Our results provide an independent confirmation of the standard $\Omega_{\rm tot}=1$ $\Lambda$CDM model within the…

We present a new data analysis method to study rectangular T^3 ``small universes" with one or two of its dimensions significantly smaller than the present horizon (which we refer to as T^1- and T^2-models, respectively). We find that the 4…

Astrophysics · Physics 2007-05-23 Angelica de Oliveira-Costa , George F. Smoot , Alexei A. Starobinsky

Recent cosmological observations hint at a deviation from the simple power-law form of the primordial spectrum of curvature perturbations. In this paper we show that in the presence of a tensor component, a turn-over in the initial spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 J. Alberto Vazquez , M. Bridges , Yin-Zhe Ma , M. P. Hobson

We present a new approach to constructing inflationary models in closed universes. Conformal embedding of closed-universe models in a de Sitter background suggests a quantisation condition on the available conformal time. This condition…

Astrophysics · Physics 2009-11-10 Anthony Lasenby , Chris Doran

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

We analyze the physical content of squeezed bispectra involving long-wavelength tensor perturbations, showing that these modes cannot be gauged away, except for the exact (unphysical) limit of infinite wavelength, $k = 0$. This result has a…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-01 Nicola Bartolo , Giovanni Battista Carollo , Sabino Matarrese , Luigi Pilo , Rocco Rollo

Recently observational lower bounds on the strength of cosmic magnetic fields were reported, based on gamma-ray flux from distant blazars. If inflation is responsible for the generation of such magnetic fields then the inflation energy…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-23 Tomohiro Fujita , Shinji Mukohyama