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Traditionally, inflationary models are analyzed in terms of parameters such as the scalar spectral index ns and the tensor to scalar ratio r, while dark energy models are studied in terms of the equation of state parameter w. Motivated by…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Stéphane Ilic , Martin Kunz , Andrew R. Liddle , Joshua A. Frieman

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

Three-year data of WMAP implies not only a negative running of the spectral index with large absolute value, but also a large positive running of running of the spectral index with order of the magnitude $10^{-2}$. We calculate the running…

Astrophysics · Physics 2009-11-11 Qing-Guo Huang

We implement a procedure by which the parameters present in the potential of Quartic Hilltop Inflation (QHI) are eliminated in favor of the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$. By doing this it is posible to…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 Gabriel German

Next generation of cosmological observations are expected to improve the measurements of several quantities connected to the primordial inflation in the early Universe. These quantities include for example improved measurements for the…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-01 Suratna Das , Rudnei O. Ramos

By writing the running of the scalar spectral index completely in terms of the scalar index $n_s$ and the tensor-to-scalar ratio $r$ we are able to impose constraints to models of inflation which are independent of the parameters of the…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-05 Gabriel German

A model independent analysis shows that the running of the spectral index of the three year WMAP results can be nicely realized in noncommutative inflation. We also re-examine some concrete noncommutative inflation models. We find that a…

Astrophysics · Physics 2009-11-11 Qing-Guo Huang , Miao Li

We present a complete computation of the scalar power spectrum in the \emph{inflation without inflaton} (IWI) framework, where the inflationary expansion is driven solely by a de~Sitter (dS) background and scalar fluctuations arise as…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-18 Marisol Traforetti , Mariam Abdelaziz , Daniele Bertacca , Raul Jimenez , Sabino Matarrese , Angelo Ricciardone

We present WarmSPy, a numerical code in Python designed to solve for the perturbations' equations in warm inflation models and compute the corresponding scalar power spectrum at CMB horizon crossing. In models of warm inflation, a radiation…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-17 Gabriele Montefalcone , Vikas Aragam , Luca Visinelli , Katherine Freese

The primordial power spectrum informs the possible inflationary histories of our universe. Given a power spectrum, the ensuing cosmic microwave background is calculated and compared to the observed one. Thus, one focus of modern cosmology…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-25 Ira Wolfson

An inflationary scenario driven by a slow rolling homogeneous scalar field whose potential $V(\Phi)$ is given by a generalized exponential function is discussed. Within the {\sl slow-roll} approximation we investigate some of the main…

Astrophysics · Physics 2008-11-26 J. S. Alcaniz , F. C. Carvalho

This paper revisits the Inflationary scenario within the framework of scalar field models possessing a non-canonical kinetic term. We obtain closed form solutions for all essential quantities associated with chaotic inflation including slow…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-03 Sanil Unnikrishnan , Varun Sahni , Aleksey Toporensky

Warm inflationary dynamics is shown to satisfy both the slow-roll and density perturbation constraints for $m_{\phi} \gg H$ or equivalently $\eta \gg 1$ and for inflaton field amplitudes much below the Planck scale, $<\phi > < m_{pl}$. I…

High Energy Physics - Phenomenology · Physics 2007-05-23 Arjun Berera

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 simple inflaton potentials well motivated by…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. R. Espinosa

The minimal warm inflation scenario proposed in Ref. [1] -- featuring an axionlike inflaton coupled to Standard Model (SM) gluons via the standard interaction $\phi G \tilde G$ -- offers a compelling bridge between inflationary dynamics and…

High Energy Physics - Phenomenology · Physics 2025-06-18 Rudnei O. Ramos , Gabriel S. Rodrigues

This paper studies the stability of warm inflationary solutions when the viscous pressure is taken into account. The latter is a very natural and physically motivated ingredient of warm inflation and is seen to widen the stability range of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Sergio del Campo , Ramón Herrera , Diego Pavón , José R. Villanueva

The scalar spectral index n is an important parameter describing the nature of primordial density perturbations. Recent data, including that from the WMAP satellite, shows some evidence that the index runs (changes as a function of the…

Astrophysics · Physics 2009-11-07 Daniel J. H. Chung , Gary Shiu , Mark Trodden

The reconstruction of a warm inflationary universe model from the scalar spectral index $n_S(N)$ and the tensor to scalar ratio $r(N)$ as a function of the number of e-folds $N$ is studied. Under a general formalism we find the effective…

General Relativity and Quantum Cosmology · Physics 2018-04-18 Ramon Herrera

Recently we have studied in great detail a model of Hybrid Natural Inflation (HNI) by constructing two simple effective field theories. These two versions of the model allow inflationary energy scales as small as the electroweak scale in…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-06 Gabriel German , Alfredo Herrera--Aguilar

A thorough MCMC analysis of any inflationary model against the current cosmological data is essential for assessing the validity of such a model as a viable inflationary model. Warm Inflation, producing both thermal and quantum…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-29 Umang Kumar , Suratna Das
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