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相关论文: No slow-roll inflation \`a la Generalized Chaplygi…

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In this paper, we undertake a unified study of background dynamics and cosmological perturbations in the presence of the Chaplygin gas. This is done by first constraining the background cosmological parameters of different Chaplygin gas…

广义相对论与量子宇宙学 · 物理学 2023-10-12 Shambel Sahlu , Heba Sami , Renier Hough , Maye Elmardi , Anna-Mia Swart , Amare Abebe

The generalized Chaplygin gas (GCG), is studied in this paper by using the latest observational data including 182 gold sample type Ia supernovae (Sne Ia) data, the ESSENCE Sne Ia data, the distance ratio from $z=0.35$ to $z=1089$ (the…

天体物理学 · 物理学 2009-11-10 Puxun Wu , Hongwei Yu

In this paper, we investigate cosmological consequences of a scenario for recently reported accelerated expansion of the Universe, in which the generalized Chaplygin gas (GCG) along with the baryonic matter are responsible for this observed…

广义相对论与量子宇宙学 · 物理学 2017-05-24 Hamid Shabani

The constant-roll inflation in the context of Galilean inflation or G-inflation is analyzed. By considering a coupling function $G(\varphi,\chi)\propto g(\varphi)\,\chi^n$ for the model of G-inflation, we find different expressions for a…

广义相对论与量子宇宙学 · 物理学 2023-04-13 Ramon Herrera , Jafar Sadeghi , Mehdi Shokri

The warm inflation scenario in view of the modified Chaplygin gas is studied. We consider the inflationary expansion is driven by a standard scalar field whose decay ratio $\Gamma$ has a generic power law dependence with the scalar field…

广义相对论与量子宇宙学 · 物理学 2017-11-22 Abdul Jawad , Shahzad Hussain , Shamaila Rani , Nelson Videla

Warm inflationary universe models in the context of generalized chaplygin gas, modified chaplygin gas, generalized cosmic chaplygin gas are being studied. The dissipative coefficient of the form $\Gamma\propto T$, weak and strong…

广义相对论与量子宇宙学 · 物理学 2016-10-27 Abdul Jawad , Sadaf Butt , Shamaila Rani

We present a scalar-field formulation of the generalized Chaplygin gas (GCG) and modified Chaplygin gas (MCG) models, in which the cosmic fluid dynamics are reproduced by canonical Lagrangians with analytically derived energy density…

宇宙学与河外天体物理 · 物理学 2025-09-23 Yi-Syuan Wu , Chuan-Jui Li , W. F. Kao

We investigate the unification scenario provided by the generalised Chaplygin gas model (a perfect fluid characterized by an equation of state p = -A/\rho^{\alpha}). Our concerns lie with a possible tension existing between background…

宇宙学与河外天体物理 · 物理学 2014-07-18 Juliano Pereira Campos , Júlio César Fabris , Rafael Perez , Oliver F. Piattella , Hermano Velten

Slow-roll inflation is analyzed in the context of modified gravity within the Palatini formalism. As shown in the literature, inflation in this framework requires the presence of non-traceless matter, otherwise it does not occur just as a…

广义相对论与量子宇宙学 · 物理学 2020-11-30 Sabit Bekov , Kairat Myrzakulov , Ratbay Myrzakulov , Diego Sáez-Chillón Gómez

We investigate non-Gaussianity in general single field models without assuming slow-roll conditions or the exact scale-invariance of the scalar power spectrum. The models considered include general single field inflation (e.g. DBI and…

宇宙学与河外天体物理 · 物理学 2011-05-13 Johannes Noller , Joao Magueijo

A new inflationary scenario driven by a slowly-rolling homogeneous scalar field whose potential $V\left(\varphi\right)$ is given by a generalized exponential function is investigated. Within the {\it slow-roll} approximation we obtain the…

宇宙学与河外天体物理 · 物理学 2024-09-17 B. W. Ribeiro , I. M. Macêdo , F. C. Carvalho

We study the main cosmological properties of the Generalized Chaplygin Gas (GCG) dark energy model at the background and perturbation levels. By using the latest cosmological data in both the background and perturbation levels, we implement…

宇宙学与河外天体物理 · 物理学 2022-03-14 S. F. Salahedin , M. Malekjani , K. Y. Roobiat , R. Pazhouhesh

Addressing the late-time accelerated expansion of the universe, known as the "dark energy problem", remains a central challenge in cosmology. While the cosmological constant is the standard explanation, alternative models such as…

广义相对论与量子宇宙学 · 物理学 2025-10-27 Gilberto Aguilar-Pérez , Miguel Cruz , Mohsen Fathi , Daniel de Jesús García-Castro , J. R. Villanueva

Non-abelian gauge field inflation is studied in the context of warm inflation scenario. We introduce this scenario as a mechanism that gives an end for gauge-flation model. Slow-roll parameters and perturbation parameters are presented for…

广义相对论与量子宇宙学 · 物理学 2015-06-17 M. R. Setare , V. Kamali

The generalized Chaplygin gas is usually defined as a barotropic perfect fluid with an equation of state $p=-A \rho^{-\alpha}$, where $\rho$ and $p$ are the proper energy density and pressure, respectively, and $A$ and $\alpha$ are positive…

广义相对论与量子宇宙学 · 物理学 2018-08-22 V. M. C. Ferreira , P. P. Avelino

The Cosmic Microwave Background (CMB) observations results reported by {\it Planck} satellite suggest a plateau characteristic in the flat potential of the inflaton field is favored to drive the Universe's early acceleration. On that note,…

宇宙学与河外天体物理 · 物理学 2025-09-10 Yogesh , Imtiyaz Ahmad Bhat , Mayukh R. Gangopadhyay

The generalized Chaplygin gas (GCG), which has an unusual perfect fluid equation of state, is another promising candidate for dark energy. We investigate the GCG scenario coupled with a baryonic matter in a newly suggested $f(Q,T)$ gravity,…

广义相对论与量子宇宙学 · 物理学 2022-06-24 Gaurav N. Gadbail , Simran Arora , P. K. Sahoo

In [arXiv:1102.1513] we introduced an inflationary scenario, Non-Abelian Gauge Field Inflation or gauge-flation for short, in which slow-roll inflation is driven by non-Abelian gauge field minimally coupled to gravity. We present a more…

高能物理 - 唯象学 · 物理学 2015-03-18 A. Maleknejad , M. M. Sheikh-Jabbari

In this work, we explore the prospect of generalizing the constant-roll condition in canonical inflationary model to non-canonical models. To find a natural generalization, we focus on three manifestations of this condition and construct…

广义相对论与量子宇宙学 · 物理学 2024-05-07 S. Mohammad Ahmadi , Nahid Ahmadi , Mehdi Shokri

The previously introduced class of two-parametric phenomenological inflationary models in General Relativity in which the slow-roll assumption is replaced by the more general, constant-roll condition is generalized to the case of $f(R)$…

宇宙学与河外天体物理 · 物理学 2017-08-15 Hayato Motohashi , Alexei A. Starobinsky