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We study primordial gravitational waves from inflation in Randall-Sundrum braneworld model. The effect of small change of the Hubble parameter during inflation is investigated using a toy model given by connecting two de Sitter branes. We…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Tsutomu Kobayashi , Hideaki Kudoh , Takahiro Tanaka

We study the generation and evolution of gravitational waves (tensor perturbations) in the context of Randall-Sundrum braneworld cosmology. We assume that the initial and final stages of the background cosmological model are given by de…

High Energy Physics - Theory · Physics 2009-11-11 Tsutomu Kobayashi , Takahiro Tanaka

We study the evolution of gravitational waves(GWs) after inflation in a brane-world cosmology embedded in five-dimensional anti-de Sitter spacetime. Contrary to the standard four-dimensional results, the GWs at the high-energy regime in…

High Energy Physics - Theory · Physics 2015-06-26 Takashi Hiramatsu , Kazuya Koyama , Atsushi Taruya

We study the quantum-mechanical generation of gravitational waves during inflation on a brane embedded in a five-dimensional anti-de Sitter bulk. To make the problem well-posed, we consider the setup in which both initial and final phases…

High Energy Physics - Theory · Physics 2009-11-11 Tsutomu Kobayashi , Takahiro Tanaka

We discuss the cosmological evolution of gravitational waves (GWs) after inflation in a brane-world cosmology embedded in five-dimensional anti-de Sitter (AdS_5) bulk spacetime. In a brane-world scenario, the evolution of GWs is affected by…

High Energy Physics - Theory · Physics 2009-11-10 Takashi Hiramatsu , Kazuya Koyama , Atsushi Taruya

We discuss the cosmological evolution of the inflationary gravitational wave background (IGWB) in the Randall-Sundrum single-brane model. In the braneworld cosmology, in which three-dimensional space-like hypersurface that we live in is…

High Energy Physics - Theory · Physics 2008-11-26 Takashi Hiramatsu

We discuss the evolution of gravitational waves in a brane-world cosmology embedded in five-dimensional anti-de Sitter spacetime. We show that during slow-roll inflation, modelled as a period of quasi-de Sitter expansion on the brane, there…

High Energy Physics - Theory · Physics 2009-10-31 David Langlois , Roy Maartens , David Wands

We calculate the amplitude of gravitational waves produced by inflation on a de Sitter brane embedded in five-dimensional anti-de Sitter bulk spacetime, extending previous calculations in Randall-Sundrum type cosmology to include the effect…

High Energy Physics - Theory · Physics 2009-11-10 Mariam Bouhmadi-Lopez , Roy Maartens , David Wands

We consider the effects of the quantum stress tensor fluctuations of a conformal field in generating gravity waves in inflationary models. We find a non-scale invariant, non-Gaussian contribution which depends upon the total expansion…

General Relativity and Quantum Cosmology · Physics 2011-12-08 Chun-Hsien Wu , Jen-Tsung Hsiang , L. H. Ford , Kin-Wang Ng

An inflationary brane model driven by a bulk inflaton with exponential potential is proposed. We find a family of exact solutions that describe power-law inflation on the brane. These solutions enable us to derive exact solutions for metric…

High Energy Physics - Theory · Physics 2009-11-10 Kazuya Koyama , Keitaro Takahashi

A Randall-Sundrum type brane-cosmological model in which slow-roll inflation on the brane is driven solely by a bulk scalar field was recently proposed by Himemoto and Sasaki. We analyze their model in detail and calculate the quantum…

General Relativity and Quantum Cosmology · Physics 2009-10-09 Norichika Sago , Yoshiaki Himemoto , Misao Sasaki

We investigate the generation of primordial gravitational waves from inflation in braneworld cosmologies with extra dimensions. Advantage of using primordial gravitational waves to probe extra dimensions is that their theory depends only on…

High Energy Physics - Theory · Physics 2007-05-23 Andrei Frolov , Lev Kofman

The main goal of this paper is to derive the primordial power spectrum for the scalar perturbations generated as a result of quantum fluctuations during an inflationary pe- riod by an alternative approach of field quantization[1-3].…

General Relativity and Quantum Cosmology · Physics 2012-02-23 M. Mohsenzadeh , A. Sojasi , E. Yusofi

We study the braneworld effective action in the two-brane Randall-Sundrum model. In the framework of this essentially-nonlocal action we reveal the origin of an infinite sequence of gravitational wave modes -- the usual massless one as well…

High Energy Physics - Theory · Physics 2009-11-07 Andrei Barvinsky , Alexander Kamenshchik , Claus Kiefer , Andreas Rathke

Cosmic inflation driven by branes wrapping the extra dimensions involves Kaluza-Klein (KK) degrees of freedom in addition to the zero-mode position of the brane which plays the role of the inflaton. As the wrapped brane passes by localized…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-02 Takeshi Kobayashi , Jun'ichi Yokoyama

We point out that the temperature fluctuations of cosmic microwave background (CMB) can be generated in a way that is different from the one usually assumed in slow-roll inflation. Our mechanism is based on vacuum fluctuations of fields…

High Energy Physics - Theory · Physics 2012-05-18 Yoshinobu Habara , Hikaru Kawai , Masao Ninomiya , Yasuhiro Sekino

The inflationary scenario for the brane world driven by the bulk inflaton is proposed. The quantum fluctuations of the inflaton is calculated and compared to those of the conventional 4-dimensional inflationary scenario. It is shown that…

High Energy Physics - Theory · Physics 2009-10-31 Shinpei Kobayashi , Kazuya Koyama , Jiro Soda

We consider the space-condensate inflation model to study the primordial gravitational waves generated in the early Universe. We calculate the energy spectrum of gravitational waves induced by the space-condensate inflation model for full…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Seoktae Koh , Bum-Hoon Lee , Gansukh Tumurtushaa

Following inflation, the Universe may pass through an early matter-dominated phase supported by the oscillating inflaton condensate. Initially small fluctuations in the condensate grow gravitationally on subhorizon scales and can collapse…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-03 Benedikt Eggemeier , Jens C. Niemeyer , Karsten Jedamzik , Richard Easther

We develop a formalism to study non-local higher-dimensional effects in braneworld scenarios from a four-dimensional effective theory point of view and check it against the well-known Garriga-Tanaka result in the appropriate limit. We then…

High Energy Physics - Theory · Physics 2008-11-26 Claudia de Rham , Scott Watson
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