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Related papers: Slow-roll inflation with a Gauss-Bonnet correction

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We study slow-roll inflation driven by a scalar field non-minimally coupled to gravity within the effective framework of Loop Quantum Cosmology (LQC), including inverse-volume corrections. We consider two physically motivated classes of…

General Relativity and Quantum Cosmology · Physics 2026-03-05 Rudranil Roy , Giovanni Otalora , Joel Saavedra , Salvatore Capozziello

We investigate the possibility of inflation with models of antisymmetric tensor field having minimal and nonminimal couplings to gravity. Although the minimal model does not support inflation, the nonminimal models, through the introduction…

General Relativity and Quantum Cosmology · Physics 2018-11-02 Sandeep Aashish , Abhilash Padhy , Sukanta Panda , Arun Rana

We calculate power spectra of cosmological perturbations at high accuracy for two classes of inflation models. We classify the models according to the behaviour of the Hubble distance during inflation. Our approximation works if the Hubble…

Astrophysics · Physics 2009-11-06 Dominik J. Schwarz , Cesar A. Terrero-Escalante , Alberto A. Garcia

There are many single field inflationary models that are consistent with the recent Planck 2018 measurements of the spectral index $n_s$ and tensor-to-scalar ratio $r$. Despite good agreement with observational data some of these models…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-18 Josh Hoffmann , David Sloan

Slow-roll inflationary scenario is considered in non-canonical scalar field model supposing a power-law function for kinetic term, and using two formalisms. In the first approach, the potential is considered as a power-law function, that is…

General Relativity and Quantum Cosmology · Physics 2017-08-15 Kh. Saaidi , A. Mohammadi , T. Golanbari

We first derive the primordial power spectra, spectral indices and runnings of both scalar and tensor perturbations of a flat inflationary universe to the second-order approximations of the slow-roll parameters, in the framework of loop…

General Relativity and Quantum Cosmology · Physics 2016-03-25 Tao Zhu , Anzhong Wang , Klaus Kirsten , Gerald Cleaver , Qin Sheng , Qiang Wu

We reconstruct the potential of minimally coupling inflation model which produces small value of the tensor-scalar ratio. In these inflation models, tensor-scalar ratio is proportional to 1/N^2 scalar spectral index is in good agreement…

General Relativity and Quantum Cosmology · Physics 2019-04-10 Jun Chen

In this paper, we investigate chaotic inflation from scalar field subjected to potential in the framework of $f(R^2, P, Q)$-gravity, where we add a correction to Einstein's gravity based on a function of the square of the Ricci scalar…

General Relativity and Quantum Cosmology · Physics 2015-09-21 Shynaray Myrzakul , Ratbay Myrzakulov , Lorenzo Sebastiani

We explore inflationary cosmology in a theory where there are two scalar fields which non-minimally couple to the Ricci scalar and an additional $R^2$ term, which breaks the conformal invariance. Particularly, we investigate the slow-roll…

High Energy Physics - Theory · Physics 2015-07-10 Kazuharu Bamba , Sergei D. Odintsov , Petr V. Tretyakov

In this paper we investigate the inflationary phenomenology of an Einstein-Gauss-Bonnet theory compatible with the GW170817 event, by imposing the constant-roll evolution on the scalar field. We develop the constant-roll GW170817-compatible…

General Relativity and Quantum Cosmology · Physics 2020-09-15 S. D. Odintsov , V. K. Oikonomou , F. P. Fronimos , S. A. Venikoudis

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…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Gabriel German , Alfredo Herrera-Aguilar , Juan Carlos Hidalgo , Roberto A. Sussman

We explore the possibility of a blue-tilted gravitational wave spectrum from potential-driven slow-roll inflation in the Horndeski theory. In Kamada et al. (2012), it was claimed that a blue gravitational wave spectrum cannot be obtained…

General Relativity and Quantum Cosmology · Physics 2020-03-02 Yosuke Mishima , Tsutomu Kobayashi

The slow roll approximation is studied for cosmological models in Hyperextended Scalar-Tensor Theories of Gravity. A procedure to obtain slow roll solutions in non-minimally coupled gravity is outlined and some examples are provided. An…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Diego F. Torres

Picking out DBI scalar field as inflation, the slow-rolling inflationary scenario is studied by attributing an exponential time function to scale factor; known as intermediate inflation. The perturbation parameters of the model are…

General Relativity and Quantum Cosmology · Physics 2017-08-15 N. Nazavari , A. Mohammadi , Z. Ossoulian , Kh. Saaidi

We reexamine inflation due to a constrained inflaton in the model of a complex scalar. Inflaton evolves along a spiral-like valley of special scalar potential in the scalar field space just like single field inflation. Sub-Planckian…

High Energy Physics - Phenomenology · Physics 2015-12-02 Romy H. S. Budhi , Shoichi Kashiwase , Daijiro Suematsu

We elucidate the counting of the relevant small parameters in inflationary perturbation theory. Doing this allows for an explicit delineation of the domain of validity of the semi-classical approximation to gravity used in the calculation…

High Energy Physics - Theory · Physics 2018-02-21 Peter Adshead , C. P. Burgess , R. Holman , Sarah Shandera

We propose a test of single-scalar inflation based on using the well-measured scalar power spectrum to reconstruct the tensor power spectrum, up to a single integration constant. Our test is a sort of integrated version of the single-scalar…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-06 D. J. Brooker , N. C. Tsamis , R. P. Woodard

Slow roll reconstruction is derived from the Hamilton-Jacobi formulation of inflationary dynamics. It automatically includes information from sub-leading terms in slow roll, and facilitatesthe inclusion of priors based on the duration on…

Astrophysics · Physics 2009-06-23 Peter Adshead , Richard Easther

We formalize the Hubble slow-roll formalism for inflationary dynamics in Randall-Sundrum Type II braneworld cosmologies, defining Hubble slow-roll parameters which can be used along with the Hamilton-Jacobi formalism. Focussing on the…

Astrophysics · Physics 2009-11-10 Erandy Ramirez , Andrew R. Liddle

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…

Astrophysics · Physics 2009-11-13 Konstantinos Tzirakis , William H. Kinney