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相关论文: Anisotropic constant-roll inflation with noncommut…

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We show how the inclusion of non-perturbative, {\em dynamical} quantum effects on the evolution of the inflaton can allow for an inflationary phase that is both consistent with cosmological constraints {\em and} avoids the problems…

高能物理 - 理论 · 物理学 2019-05-15 R. Holman , B. Richard

A natural combination of the first and second derivatives of the scalar potential was achieved in a framework of an alternative refined de Sitter conjecture recently proposed in the literature. In this work, we study various inflation…

广义相对论与量子宇宙学 · 物理学 2022-12-07 Jureeporn Yuennan , Phongpichit Channuie

We determine the power spectrum for inflation models covering all regimes from cold (isentropic) to warm (nonisentropic) inflation. We work in the context of the stochastic inflation approach, which can nicely describe both types of…

宇宙学与河外天体物理 · 物理学 2013-03-27 Rudnei O. Ramos , L. A. da Silva

We study constraints on a number of patch inflationary models in noncommutative spacetime using a compilation of recent high-precision observational data. In particular, the four-dimensional General Relativistic (GR) case, the…

天体物理学 · 物理学 2007-05-23 Gianluca Calcagni , Shinji Tsujikawa

Swampland conjectures have attracted quite some interest in the cosmological community. They have been shown to have wide ranging implications , like constraints on inflationary models, primordial black holes, dark energy to name a few.…

高能物理 - 理论 · 物理学 2024-08-02 Oem Trivedi

In this paper, we study a particular type of inflation by using non-local Friedman equations that are somehow derived from the zero levels of string field theory and express a tachyonic action. Then, we challenge it by further refining de…

高能物理 - 理论 · 物理学 2023-08-02 J. Sadeghi , B. Pourhassan , S. Noori Gashti , İ. Sakallı , M. R. Alipour

We consider a warm inflationary scenario in which the two dominant matter components present in the early Universe, the scalar field, and the radiation fluid, evolve with different four-velocities. This cosmological system is mathematically…

广义相对论与量子宇宙学 · 物理学 2021-03-15 Tiberiu Harko , Haidar Sheikhahmadi

In this work, we study early-time inflation within a class of $f(R, \phi, X)$ gravity models under a constant-roll condition. Employing a generalized potential of the form $V(\phi)^\sigma$, we derive expressions for the spectral index $n_s$…

广义相对论与量子宇宙学 · 物理学 2025-10-15 Ali I. Keskin , Mehmet Yaşar , K. Kurt

Ultra slow-roll inflation has recently been used to challenge the non-Gaussianity consistency relation. We show that this inflationary scenario belongs to a one parameter class of models and we study its properties and observational…

宇宙学与河外天体物理 · 物理学 2013-05-30 Jerome Martin , Hayato Motohashi , Teruaki Suyama

We consider slow-roll inflation for a single scalar field with an arbitrary potential and an arbitrary nonminimal coupling to the Gauss-Bonnet term. By introducing a combined hierarchy of Hubble and Gauss-Bonnet flow functions, we…

高能物理 - 理论 · 物理学 2014-11-20 Zong-Kuan Guo , Dominik J. Schwarz

Recently a class of inflationary models satisfying the constant rate of roll constraint, $\ddot{\phi}+(3+\alpha)H\dot{\phi}=0$, has been studied and compared with the latest cosmological observational data. We consider the broader class of…

广义相对论与量子宇宙学 · 物理学 2019-11-11 B. Boisseau , H. Giacomini

We study constant-roll inflation using the $\beta$-function formalism. We show that the constant rate of the inflaton roll is translated into a first order differential equation for the $\beta$-function which can be solved easily. The…

宇宙学与河外天体物理 · 物理学 2018-02-09 F. Cicciarella , J. Mabillard , M. Pieroni

We study the generation of primordial perturbations in a (single-field) slow-roll inflationary universe. In momentum space, these (Gaussian) perturbations are characterized by a zero mean and a non-zero variance $\Delta^2(k, t)$. However,…

高能物理 - 理论 · 物理学 2010-04-06 Ivan Agullo , Jose Navarro-Salas , Gonzalo J. Olmo , Leonard Parker

One class of single-field inflationary models compatible with the recently-conjectured Swampland criteria would be those in which a Hubble slow-roll parameter $\epsilon_\text{H}$ is not the same as $\epsilon_\text{V} \sim (V'/V)^2$.…

高能物理 - 理论 · 物理学 2019-03-06 Suddhasattwa Brahma , Md. Wali Hossain

We investigate the cosmic inflation within a class of the scalar-tensor model with the scalar-dependent non-minimal kinetic couplings. The inflationary dynamical potential will be applied. Using the slow-roll approximation, we compute…

广义相对论与量子宇宙学 · 物理学 2025-12-01 Feyzollah Younesizadeh , Davoud Kamani

In this article we study a constant-roll inflationary model in the context of the DGP brane-world cosmology caused by a quintessence scalar field. We determine an analytical solution for the Friedman equation coupled to the equation of…

广义相对论与量子宇宙学 · 物理学 2022-10-20 Arvin Ravanpak , Golnaz Farpour Fadakar

We consider the torsional completion of gravity with spinor and scalar fields: we show how in this environment conditions of extreme symmetry or specific approximations imply the scalar field to be constant, so that slow-roll takes place…

广义相对论与量子宇宙学 · 物理学 2017-07-07 Luca Fabbri

In this work we study the chromo-natural inflation model in the anisotropic setup. Initiating inflation from Bianchi type-I cosmology, we analyze the system thoroughly during the slow-roll inflation, from both analytical and numerical…

高能物理 - 理论 · 物理学 2015-06-17 A. Maleknejad , E. Erfani

We extend the standard theory of cosmological perturbations to homogeneous but anisotropic universes. We present an exhaustive computation for the case of a Bianchi I model, with a residual isotropy between two spatial dimensions, which is…

天体物理学 · 物理学 2008-11-26 A. E. Gumrukcuoglu , Carlo R. Contaldi , Marco Peloso

In this article, we examine the effects of anisotropy on a model of canonical warm inflation with the power-law potential. The results of this model are compared to Planck satellite observational data. Using a conventional local scalar…

广义相对论与量子宇宙学 · 物理学 2022-05-05 Zahra Ghadiri , Ali Aghamohammadi , Abdollah Refaei