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相关论文: Observational constraints on tachyon and DBI infla…

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We propose new slow-roll approximations for inflationary models with the Gauss-Bonnet term. We find more accurate expressions of the standard slow-roll parameters as functions of the scalar field. To check the accuracy of approximations…

广义相对论与量子宇宙学 · 物理学 2024-09-24 Ekaterina O. Pozdeeva , Maria A. Skugoreva , Alexey V. Toporensky , Sergey Yu. Vernov

We consider slow-roll inflation in the context of a modified Brans-Dicke dilaton gravity. From a two self-interacting potentials $V(\phi)$, we reproduce a Starobinsky-like potential and, commonly in syperstring models, an exponential tail…

广义相对论与量子宇宙学 · 物理学 2024-11-11 Abraão J. S. Capistrano , Gilberto M. Kremer

If a coupling between the inflaton and the Gauss-Bonnet term is introduced, many models of inflation that were ruled out by the most recent Planck data can be made viable again. The predictions for the scalar spectral index and…

广义相对论与量子宇宙学 · 物理学 2025-04-22 Kamil Mudrunka , Kazunori Nakayama

We propose new versions of the slow-roll approximation for inflationary models with nonminimally coupled scalar fields. We derive more precise expressions for the standard slow-roll parameters as functions of the scalar field. To verify the…

广义相对论与量子宇宙学 · 物理学 2025-05-30 Ekaterina O. Pozdeeva , Maria A. Skugoreva , Alexey V. Toporensky , Sergey Yu. Vernov

Canonical models of single-field, slow-roll inflation do not lead to appreciable non-Gaussianity, unless derivative interactions of the inflaton become uncontrollably large. We propose a novel slow-roll scenario where scalar perturbations…

高能物理 - 理论 · 物理学 2016-05-25 David Pirtskhalava , Luca Santoni , Enrico Trincherini , Filippo Vernizzi

We place observational constraints on slow-variation single-field inflationary models by carrying out the cosmological Monte Carlo simulation with the recent data of Planck combined with the WMAP large-angle polarization, baryon acoustic…

宇宙学与河外天体物理 · 物理学 2013-11-12 Shinji Tsujikawa , Junko Ohashi , Sachiko Kuroyanagi , Antonio De Felice

While moving down the potential on its classical slow roll trajectory, the inflaton field is subject to quantum jumps, which take it up or down the potential at random. In "stochastic inflation", the impact of these quantum jumps is modeled…

高能物理 - 理论 · 物理学 2015-05-20 Larissa Lorenz

We study a single field inflationary model modified by a non-minimal coupling term between the Ricci scalar $R$ and the scalar field $\varphi$ in the context of constant-roll inflation. The first-order formalism is used to analyse the…

广义相对论与量子宇宙学 · 物理学 2021-08-11 Mehdi Shokri , Jafar Sadeghi , Mohammad Reza Setare , Salvatore Capozziello

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

Many alternatives to canonical slow-roll inflation have been proposed over the years, one of the main motivations being to have a model, capable of generating observable values of non-Gaussianity. In this work, we (re-)explore the physical…

高能物理 - 理论 · 物理学 2016-07-06 David Pirtskhalava , Luca Santoni , Enrico Trincherini

We derive a lower bound on the field excursion for the tachyon inflation, which is determined by the amplitude of the scalar perturbation and the number of $e$-folds before the end of inflation. Using the relation between the observables…

广义相对论与量子宇宙学 · 物理学 2017-08-17 Qin Fei , Yungui Gong , Jiong Lin , Zhu Yi

Using $\delta N$ formalism, in the context of a generic multi-field inflation driven on a non-flat field space background, we revisit the analytic expressions of the various cosmological observables such as scalar/tensor power spectra,…

高能物理 - 理论 · 物理学 2014-10-07 Xin Gao , Tianjun Li , Pramod Shukla

Nongaussian statistics are a powerful discriminant between inflationary models, particularly those with noncanonical kinetic terms. Focusing on theories where the Lagrangian is an arbitrary Lorentz-invariant function of a scalar field and…

宇宙学与河外天体物理 · 物理学 2015-03-19 Clare Burrage , Raquel H. Ribeiro , David Seery

We take a pragmatic, model independent approach to single field slow-roll canonical inflation by imposing conditions, not on the potential, but on the slow-roll parameter $\epsilon(\phi)$ and its derivatives $\epsilon^{\prime }(\phi)$ and…

宇宙学与河外天体物理 · 物理学 2016-08-17 Gabriel German , Alfredo Herrera-Aguilar , Juan Carlos Hidalgo , Roberto A. Sussman

The simple $m^2\phi^2$ potential as an inflationary model is coming under increasing tension with limits on the tensor-to-scalar ratio $r$ and measurements of the scalar spectral index $n_s$. Cubic Galileon interactions in the context of…

宇宙学与河外天体物理 · 物理学 2018-04-12 Héctor Ramírez , Samuel Passaglia , Hayato Motohashi , Wayne Hu , Olga Mena

We shall investigate the inflation for the D-brane model, motivated by the modified gravity $F(\phi,T)$. This gravity has been recently introduced in the literature. The feasibility of the D-brane inflation theory in the $F(\phi,T)$-gravity…

广义相对论与量子宇宙学 · 物理学 2025-08-04 Feyzollah Younesizadeh , Davoud Kamani

We make a more general determination of the inflationary observables in the standard 4-D and 5-D single-field inflationary scenarios, by the exact reconstruction of the dynamics of the inflation potential during the observable inflation…

宇宙学与河外天体物理 · 物理学 2009-11-10 L. A. Popa , N. Mandolesi , A. Caramete , C. Burigana

We analyze the spectrum of density perturbations generated in models of the recently discovered "D-cceleration" mechanism of inflation. In this scenario, strong coupling quantum field theoretic effects sum to provide a DBI-like action for…

高能物理 - 理论 · 物理学 2009-11-10 Mohsen Alishahiha , Eva Silverstein , David Tong

We consider non-canonical generalizations of two classes of simple single-field inflation models. First, we study the non-canonical version of "ultra-slow roll" inflation, which is a class of inflation models for which quantum modes do not…

天体物理学 · 物理学 2009-11-13 Konstantinos Tzirakis , William H. Kinney

In this paper, an elegant mathematical approach is introduced to solve the equations of warm inflationary model without using extra approximations other than slow-roll. This important inflationary method known as Hamilton-Jacobian…

广义相对论与量子宇宙学 · 物理学 2020-04-08 R. Saleem , M. Zubair