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Related papers: Equation-of-State Parameter for Reheating

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Evidence from the BICEP2 experiment for a significant gravitational-wave background has focussed attention on inflaton potentials $V(\phi) \propto \phi^\alpha$ with $\alpha=2$ ("chaotic" or "$m^2\phi^2$" inflation) or with smaller values of…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-30 Liang Dai , Marc Kamionkowski , Junpu Wang

We present constraints on the reheating era within the string Fibre Inflation scenario, in terms of the effective equation-of-state parameter of the reheating fluid, $w_{reh}$. The results of the analysis, completely independent on the…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-11 Paolo Cabella , Alessandro Di Marco , Gianfranco Pradisi

We explore possible constraints on the inflationary equation state: p=w\rho. While w must be close to -1 for those modes that contribute to the observed power spectrum, for those modes currently out of experimental reach, the constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Lotty Ackerman , Willy Fischler , Sandipan Kundu , Navin Sivanandam

We eliminate the parameters originally present in models of inflation of the $\alpha$-attractor type in favor of the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$. We then write expressions for the number of $e$-folds…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-02 Gabriel German

Reheating connects the inflationary universe to the radiation-dominated evolution of standard Big Bang cosmology. Due to the lack of direct observations, we rely on indirect bounds on this phase from the Cosmic Microwave Background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-17 Pankaj Saha

We investigate a constraint on reheating followed by alpha-attractor-type inflation (the E-model and T-model) from an observation of the spectral index n_s. When the energy density of the universe is dominated by an energy component with…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-04 Yoshiki Ueno , Kazuhiro Yamamoto

In this paper we study the reheating constraints on inflationary models considering perturbatively decaying inflaton. Important difference with the existing analysis is the inclusion of explicit decaying dynamics of inflaton during…

High Energy Physics - Theory · Physics 2020-11-05 Debaprasad Maity

We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, $w$, during the epoch of inflaton decay, the reheating temperature, $T_{\rm reh}$, and the…

High Energy Physics - Phenomenology · Physics 2015-08-06 John Ellis , Marcos A. G. Garcia , Dimitri V. Nanopoulos , Keith A. Olive

For the subclass of Horndeski theory of gravity, we investigate the effects of reheating on the predictions of natural inflation. In the presence of derivative self-interaction of a scalar field and its kinetic coupling to the Einstein…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-13 Chen-Hsu Chien , Seoktae Koh , Gansukh Tumurtushaa

Tachyon inflation is one of the most attractive models of noncannonical inflation motivated by string theory. In this work we revisit the constraints on tachyon inflation with inverse $\cosh$ potential and exponential potential considering…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-05 Akhilesh Nautiyal

Future research studies of cosmic microwave background polarization seems likely to provide a more improved upper bound of $r \le 0.03$ on the tensor-to-scalar ratio(r). In our work, we have done the reheating study of mutated hilltop…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-12 Sudhava Yadav , Dhwani Gangal , K. K. Venkataratnam

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…

General Relativity and Quantum Cosmology · Physics 2017-08-17 Qin Fei , Yungui Gong , Jiong Lin , Zhu Yi

The study of reheating in inflationary models is crucial for understanding the early universe and gaining insights into inflationary dynamics and parameters. The reheating temperature $T_{re}$ and the duration of the reheating phase,…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-02 Gabriel German , Juan Carlos Hidalgo , Luis E. Padilla

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

Reheating phase of inflationary Universe can be modeled by parameters $T_{\text{reh}}$, $\bar{w}_{\text{reh}}$ and $N_{\text{reh}}$, which can be constrained by the scalar spectral amplitude $A_{s}$ and the scalar spectral index $n_{s}$. On…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-22 Rajesh Goswami , Urjit A. Yajnik

In this work we revisit constraints on K-inflation with DBI kinetic term and power-law kinetic term from reheating. For DBI kinetic term we choose monomial potentials, $V\propto \phi^n$ with $n=2/3\,,1\,,\,2$ and $4$, and natural inflaton…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-27 Pooja Pareek , Akhilesh Nautiyal

The Reheating era of inflationary universe can be parameterized by various parameters like reheating temperature \(T_{\text{re}}\), reheating duration \(N_{\text{re}}\) and average equation of state parameter \(\overline{\omega…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-14 Sudhava Yadav , Rajesh Goswami , K. K Venkataratnam , Urjit A. Yajnik

The temperature at the end of reheating and the length of this cosmological phase can be bound to the inflationary observables if one considers the cosmological evolution from the time of Hubble crossing until today. There are many examples…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Rodolfo C. de Freitas , Sergio V. B. Gonçalves

In many models of inflation, reheating is realized through a coupling between the inflaton and the Higgs boson. Often, the mass of the inflaton is of order $10^{13}~$GeV determined by the amplitude of the scalar fluctuation spectrum.…

High Energy Physics - Phenomenology · Physics 2025-08-19 Yann Cado , Mathieu Gross , Yann Mambrini , Keith Olive

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
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