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相关论文: Density perturbations in warm inflation and COBE n…

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Warm inflation in the framework of locally rotationally symmetric Bianchi type I universe model in the Hamilton-Jacobi formalism is being considered. Matter-Radiation fluid in warm inflation, endowed with and without a viscous pressure. For…

广义相对论与量子宇宙学 · 物理学 2023-10-25 M Tirandari , A Mohammadi

Warm inflation in the non minimal derivative coupling model with a general dissipation coefficient is considered. We investigate conditions for the existence of the slow roll approximation and study cosmological perturbations. The spectral…

广义相对论与量子宇宙学 · 物理学 2017-03-08 H. Mohseni Sadjadi , Parviz Goodarzi

We explore the homogeneous background dynamics and the evolution of generated perturbations of cosmological inflation that is driven by multiple scalar fields interacting with a perfect fluid.Then we apply the method to warm inflation…

广义相对论与量子宇宙学 · 物理学 2018-04-04 Yang-Yang Wang , Jian-Yang Zhu , Xiao-Min Zhang

We argue that a $\Lambda$-inflation model can ensure large relative contribution of cosmic gravity waves into the $\Delta T/T$ at COBE scale preserving at the same time a near scale-invariant spectrum of cosmological density perturbations…

天体物理学 · 物理学 2009-10-31 Vladimir N. Lukash

If an adiabatic density perturbation is responsible for large scale structure and the cmb anisotropy, its spectral index $n$ will be measured in the forseeable future with an accuracy $\Delta n\sim .01$. This is precisely the kind of…

高能物理 - 唯象学 · 物理学 2016-09-06 David H. Lyth

In these lectures I review the standard hot big-bang cosmology, emphasizing its successes, its shortcomings, and its major challenge---a detailed understanding of the formation of structure in the Universe. I then discuss the motivations…

天体物理学 · 物理学 2007-05-23 Michael S. Turner

We investigate the cosmological perturbation theory and calculate the perturbation spectra in the warm $k$-inflation. Unlike the scalar perturbations of $k$-inflation in the cold inflationary scenario, entropy perturbations should be…

广义相对论与量子宇宙学 · 物理学 2018-04-18 Zhi-Peng Peng , Jia-Ning Yu , Xiao-Min Zhang , Jian-Yang Zhu

We derive the implications for anisotropies in the cosmic microwave background following from a model of inflation in which a bare cosmological constant is gradually screened by an infrared process in quantum gravity. The model predicts…

天体物理学 · 物理学 2015-06-24 L. R. Abramo , N. C. Tsamis , R. P. Woodard

We asses the contribution to the observed large scale anisotropy of the cosmic microwave background radiation, arising from both gravity waves as well as adiabatic density perturbations, generated by a common inflationary mechanism in the…

高能物理 - 唯象学 · 物理学 2009-10-22 Tarun Souradeep , Varun Sahni

I consider the COBE data coarse-grained field that characterize the now observable universe for a model of warm inflation which takes into account the thermal coupled fluctuations of the scalar field with the thermal bath. The power…

广义相对论与量子宇宙学 · 物理学 2011-08-11 Mauricio Bellini

We present the results of a detailed study of how isocurvature axion fluctuations are converted into adiabatic metric perturbations through axion decay, and discuss the constraints on the parameters of pre-big bang cosmology needed for…

高能物理 - 唯象学 · 物理学 2010-04-05 V. Bozza , M. Gasperini , M. Giovannini , G. Veneziano

We study adiabatic (curvature) and entropy (isocurvature) perturbations produced during a period of cosmological inflation that is driven by multiple scalar fields with an arbitrary interaction potential. A local rotation in field space is…

天体物理学 · 物理学 2009-10-31 Christopher Gordon , David Wands , Bruce A. Bassett , Roy Maartens

Isentropic and isocurvature axion inflationary perturbations are studied in detail. If isocurvature perturbations are present, COBE requires the inflationary Hubble constant to be rather small, $H_{I} \stackrel{<}{\sim} 10^{12}$GeV,…

天体物理学 · 物理学 2016-08-30 Stephen D. Burns

We show that, in warm inflation, the nearly constant Hubble rate and temperature lead to an adiabatic evolution of the number density of particles interacting with the thermal bath, even if thermal equilibrium cannot be maintained. In this…

高能物理 - 唯象学 · 物理学 2018-02-20 Mar Bastero-Gil , Arjun Berera , Rudnei O. Ramos , Joao G. Rosa

Anisotropic inflation is a model succeeded in explaining statistical anisotropy. Warm inflation is a model succeeded in providing a mechanism of reheating during inflation. We study anisotropic warm inflation focusing on the cosmic no-hair…

高能物理 - 理论 · 物理学 2023-06-09 Sugumi Kanno , Ann Mukuno , Jiro Soda , Kazushige Ueda

The validity of warm inflation is investigated in the light of recent CMB missions in both strong and weak dissipative regimes. The tensor to scalar ratio of various inflationary models is found to be consistent with the recent CMB results…

广义相对论与量子宇宙学 · 物理学 2025-08-15 Anupama B , P K Suresh

After introducing gauge-invariant cosmological perturbation theory we give an improved set of governing equations for multiple fluids including energy transfer. Having defined adiabatic and entropic perturbations we derive the…

天体物理学 · 物理学 2007-05-23 Karim A. Malik

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…

宇宙学与河外天体物理 · 物理学 2011-03-23 Masa-aki Watanabe , Sugumi Kanno , Jiro Soda

We consider warm inflation in the context of holographic cosmology. The weak and the strong dissipative regime are analysed in the slow-roll approximation and within what is known as intermediate inflation. For an appropriate choice of the…

高能物理 - 理论 · 物理学 2022-03-11 Zahra Bouabdallaoui , Ahmed Errahmani , Mariam Bouhmadi-López , Taoufik Ouali

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…

天体物理学 · 物理学 2011-07-19 V. N. Lukash , E. V. Mikheeva , V. Muller , A. M. Malinovsky