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We study the evolution of the cosmological perturbations after inflation in curvaton models where the non-relativistic curvaton decays into both radiation and a cold dark matter component. We calculate the primordial curvature and…

Astrophysics · Physics 2009-11-10 Sujata Gupta , Karim A. Malik , David Wands

We revisit the dynamics of the curvaton in detail taking account of effects from thermal environment, effective potential and decay/dissipation rate for general field values and couplings. We also consider the curvature perturbation…

High Energy Physics - Phenomenology · Physics 2015-06-18 Kyohei Mukaida , Kazunori Nakayama , Masahiro Takimoto

We present a gauge-invariant formalism to study the evolution of the curvature and entropy perturbations in the case in which spatial and time variations of the inflaton decay rate into ordinary matter are present. During the reheating…

Astrophysics · Physics 2009-11-10 Sabino Matarrese , Antonio Riotto

We present a systematic study of the amplitude of the primordial perturbation in curvaton models with self-interactions, treating both renormalizable and non-renormalizable interactions. In particular, we consider the possibility that the…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Kari Enqvist , Sami Nurmi , Gerasimos Rigopoulos , Olli Taanila , Tomo Takahashi

In contrast to the inflaton's case, the curvature perturbations due to the curvaton field depend strongly on the evolution of the curvaton before its decay. We study in detail the dynamics of the curvaton evolution during and after…

High Energy Physics - Phenomenology · Physics 2008-11-26 Konstantinos Dimopoulos , George Lazarides , David Lyth , Roberto Ruiz de Austri

The ratio of the curvaton energy density to that of the dominant component of the background sources may be constant during a significant period in the evolution of the Universe. The possibility of having tracking curvatons, whose decay…

High Energy Physics - Phenomenology · Physics 2009-11-10 Massimo Giovannini

In an inflationary cosmology, the observed primoridal density perturbation could come from the quantum fluctuations of another light 'curvaton' field, rather than the inflaton. In this case, it is essential that the curvaton decays,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Kari Enqvist , Rose N. Lerner , Olli Taanila

We propose a new variant model of the modulated reheating. If particles have large scale fluctuations on their velocities, or equivalently their Lorentz factors, the decay rate also fluctuates and the curvature perturbation is induced via…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Kazunori Nakayama , Teruaki Suyama

The curvaton paradigm can realise a part of or all the observed curvature perturbation. Based on the stochastic formalism of inflation and closed-form exact distributions therein, the distribution of the curvature perturbation is presented…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 Koki Tokeshi

Considering the curvaton field that follows dissipative slow-roll equation, we show that the field can lead to entropy production and generation of curvature perturbation after reheating. Spectral index is calculated to discriminate warm…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 Tomohiro Matsuda

We consider the effects of the curvature energy term on thermal strange quark matter nucleation in dense neutron matter. Lower bounds on the temperature at which this process can take place are given and compared to those without the…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. E. Horvath

We present a gauge invariant formalism to study the evolution of curvature perturbations during decay of the inflaton or some other field that dominates the energy density. We specialize to the case where the total curvature perturbation…

Astrophysics · Physics 2015-06-24 Anupam Mazumdar , Marieke Postma

We study density perturbations, including their non-Gaussianity, in models in which the decay rate of the curvaton depends on another light scalar field, denoted the modulaton. Although this model shares some similarities with the standard…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 David Langlois , Tomo Takahashi

Recently, the primordial non-Gaussianity in the curvaton model has been predicted assuming sudden decay of the curvaton. We extend the calculation to non-instantaneous decay by employing delta N -formalism. The difference between the…

Astrophysics · Physics 2007-05-23 Jussi Valiviita , Misao Sasaki , David Wands

We use the delta N -formalism to investigate the non-Gaussianity of the primordial curvature perturbation in the curvaton scenario for the origin of structure. We numerically calculate the full probability distribution function allowing for…

Astrophysics · Physics 2010-04-06 Misao Sasaki , Jussi Valiviita , David Wands

The impact of temperature-induced deformations and shape fluctuations on the particle stability and decay processes has been investigated across the isotopes of hot nuclear systems with $Z = 28$ to $50$, with focus on astrophysically…

Nuclear Theory · Physics 2026-03-09 Mamta Aggarwal , Pranali Parab , G. Saxena

In the curvaton scenario, primordial curvature perturbations are produced by a second field that is sub-dominant during inflation. Depending on how the curvaton decays [possibly producing baryon number, lepton number, or cold dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-23 Tristan L. Smith , Daniel Grin

We study primordial density perturbations generated by the late decay of a curvaton field whose decay rate may be modulated by the local value of another isocurvature field, analogous to models of modulated reheating at the end of…

High Energy Physics - Theory · Physics 2015-06-12 Hooshyar Assadullahi , Hassan Firouzjahi , Mohammad Hossein Namjoo , David Wands

The curvature effect may be responsible for the steep decay phase observed in gamma-ray bursts. For testing the curvature effect with observations, the zero time point $t_0$ adopted to plot observer time and flux on a logarithmic scale…

High Energy Astrophysical Phenomena · Physics 2017-05-24 Da-Bin Lin , Hui-Jun Mu , Rui-Jing Lu , Tong Liu , Wei-Min Gu , Yun-Feng Liang , Xiang-Gao Wang , En-Wei Liang

A three fluid system describing the decay of the curvaton is studied by numerical and analytical means. We place constraints on the allowed interaction strengths between the fluids and initial curvaton density by requiring that the curvaton…

Astrophysics · Physics 2010-01-06 Tuomas Multamaki , Jani Sainio , Iiro Vilja
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