English
Related papers

Related papers: Slow-roll reconstruction for running spectral inde…

200 papers

The WMAP results on the scalar spectral index n and its running with scale, though preliminary, open a very interesting window to physics at very high energies. We address the problem of finding inflaton potentials well motivated by…

High Energy Physics - Phenomenology · Physics 2009-11-11 G. Ballesteros , J. A. Casas , J. R. Espinosa

We revisit the status of hybrid inflation in the light of Planck and recent BICEP2 results, taking care of possible transient violations of the slow-roll conditions as the field passes from the large field to the vacuum dominated phase. The…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-05 Sebastien Clesse , Jeremy Rekier

Assuming that the e-folding number is just determined by the change of the scale factor, the tachyonic inflation theory in LQC has been discussed. Considering the tachyon field with exponential potential and inverse quadratic potential, we…

General Relativity and Quantum Cosmology · Physics 2014-12-16 Kui Xiao , Xiao-Kai He , Fei Huang , Jian-Yang Zhu

I generalize the inflationary flow equations of Hoffman and Turner to arbitrary order in slow roll. This makes it possible to study the predictions of slow roll inflation in the full observable parameter space of tensor/scalar ratio $r$,…

Astrophysics · Physics 2009-11-07 William H. Kinney

Seemingly unrelated models of inflation that originate from different physical setups yield, in some cases, identical predictions for the currently constrained inflationary observables. In order to classify the available models, we propose…

High Energy Physics - Phenomenology · Physics 2017-04-19 Laur Järv , Kristjan Kannike , Luca Marzola , Antonio Racioppi , Martti Raidal , Mihkel Rünkla , Margus Saal , Hardi Veermäe

We re-examine the importance of slow-roll corrections during the evolution of cosmological perturbations in models of multi-field inflation. We find that in many instances the presence of light degrees of freedom leads to situations in…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-28 Anastasios Avgoustidis , Sera Cremonini , Anne-Christine Davis , Raquel H. Ribeiro , Krzysztof Turzynski , Scott Watson

In this work we study slow-roll inflation for a vector-tensor model with massive vector fields non-minimally coupled to gravity. The model under consideration has arbitrary parameters for each geometrical coupling. Taking into account a…

General Relativity and Quantum Cosmology · Physics 2016-12-21 A. Oliveros

Recent fits of cosmological parameters by the Wilkinson Microwave Anisotropy Probe (WMAP) measurement favor a primordial scalar spectrum with varying index. This result, if stands, could severely constrain inflation model buildings. Most…

Astrophysics · Physics 2008-11-26 Bo Feng , Mingzhe Li , Ren-Jie Zhang , Xinmin Zhang

The framework of a kind of noncanonical warm inflation is introduced, and the dynamical equations of this scenario are presented. We propose the slow roll approximations and give some redefining slow roll parameters in this scenario which…

General Relativity and Quantum Cosmology · Physics 2021-01-13 Xiao-Min Zhang , Ang Fu , Kai Li , Qian Li , Peng-Cheng Chu , Hong-Yang Ma , Jian-Yang Zhu

The slow rolling inflation is dual to the random walk of conformal zero-mode. The 2 dimensional Fokker-Planck theory predicts the slow roll parameters of 4d inflation theory. The O(N) enhancements of the two point functions, N is the…

High Energy Physics - Theory · Physics 2023-05-02 Yoshihisa Kitazawa

Analyses of inflation models are usually conducted assuming a specific range---e.g., $N_k \simeq 50-60$--of the number $N_k$ of $e$-folds of inflation. However, the analysis can also be performed by taking into account constraints imposed…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-23 Lingyuan Ji , Marc Kamionkowski

Single-field slow-roll inflation with a non-vacuum initial state has an enhanced bispectrum in the local limit. We numerically calculate the local-type fNL signal in the CMB that would be measured for such models (including the full…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-19 Jonathan Ganc

From the assumption that the slow roll parameter $\epsilon$ has a Lorentzian form as a function of the e-folds number $N$, a successful model of a quintessential inflation is obtained, as succinctly studied in \cite{Benisty:2020xqm}. The…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-07 David Benisty , Eduardo I. Guendelman

The slow-roll approximation to inflation is ultimately justified by the presence of inflationary attractors for the orbits of the solutions of the dynamical equations in phase space. There are many indications that the inflaton field…

General Relativity and Quantum Cosmology · Physics 2011-08-11 Valerio Faraoni

We investigate inflationary scenarios driven by a class of potentials which are similar in form to those that arise in certain minimal supersymmetric extensions of the standard model. We find that these potentials allow a brief period of…

Rapid-turn slow-roll inflationary trajectories have been shown to be an attractor in two-field models, provided the turn rate is near constant and larger than the slow-roll parameters. These trajectories can produce primordial spectra…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-06 Raul Wolters , Oksana Iarygina , Ana Achucarro

We adopt the double field natural inflation model motivated by the non-perturbative effects of supergravity and superstring theory to do the slow roll analysis. We show that when the parameters are suitably chosen, there exist ranges of…

General Relativity and Quantum Cosmology · Physics 2019-04-12 Ping Kwan Man Ellgan

We present a new inflation model, known as noncommutative decrumpling inflation, in which space has noncommutative geometry with time variability of the number of spatial dimensions. Within the framework of noncommutative decrumpling…

High Energy Physics - Theory · Physics 2009-11-10 Forough Nasseri , S. A. Alavi

We investigate the influence on the inflationary predictions from the reheating processes characterized by the $e$-folding number $N_{\mathrm{reh}}$ and the effective equation-of-state parameter $w_{\mathrm{reh}}$ during the reheating…

General Relativity and Quantum Cosmology · Physics 2015-09-10 Rong-Gen Cai , Zong-Kuan Guo , Shao-Jiang Wang

In this work, we studied the slow-roll approximation of cosmic inflation within the context of $f(R,T)$ gravity, where $R$ is the scalar curvature, and $T$ is the trace of the energy-momentum tensor. By choosing a minimal coupling between…

General Relativity and Quantum Cosmology · Physics 2021-01-12 Mauricio Gamonal