Article
Astronomy & Astrophysics
Gabriele Montefalcone, Vikas Aragam, Luca Visinelli, Katherine Freese
Summary: This study examines the effect of the original cosine potential on warm natural inflation. The presence of a radiation bath during inflation introduces a dissipation rate in the equation of motion for the inflaton field, potentially reducing the necessary field excursion for a viable period of inflation. We investigate whether this dissipation can avoid the requirement of a large decay constant in cold cosine natural inflation. However, we find that accommodating a significantly sub-Planckian decay constant in the presence of temperature-dependent dissipation is challenging.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Yue Qiu, Lorenzo Sorbo
Summary: The spectrum of tensor perturbations in warm inflation was computed, revealing a new contribution related to the direct production of gravitational waves by the thermal bath. This new contribution can exceed the standard one in certain regions of parameter space.
Article
Astronomy & Astrophysics
Mehrdad Mirbabayi, Andrei Gruzinov
Summary: Sphaleron heating is proposed as a mechanism for warm inflation when the inflaton is coupled to pure Yang-Mills as an axion. The presence of heating introduces a friction coefficient gamma proportional to T-3 in the inflaton's equation of motion, as well as a thermal contribution to cosmological fluctuations. In the absence of knowledge about the inflaton potential, non-Gaussianity is the most promising approach for detecting the signatures of this model. By extending previous work, we compute the scalar three-point correlation function and identify distinct features in the squeezed and folded limits. As a detection strategy, we find that combining the equilateral template with a new template yields a high overlap with the shape of non-Gaussianity for 0.01 <= gamma/H <= 1000, with 0.7 < |f(NL)| < 50 in this range.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Mahmoud AlHallak, Khalil Kalid Al-Said, Nidal Chamoun, Moustafa Sayem El-Daher
Summary: We investigate natural inflation within the warm inflation paradigm, considering non-minimal coupling to gravity and both strong and weak dissipation limits. We show that for a T-linearly dependent dissipative term, it can accommodate the observables n(s) and r given by Planck 2018 constraints, but with a too-small e-folding number to solve the horizon problem. A T-cubically dependent dissipative term may provide a solution to this e-folding number issue.
Correction
Astronomy & Astrophysics
Kim V. Berghaus, Peter W. Graham, David E. Kaplan
Summary: The statement mentions the correction of minor mistakes in equations in section 4.1 and updates the viable parameter range of the model quoted in section 4.2 accordingly.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Subhra Bhattacharya
Summary: Thermal fluctuations during the inflationary epoch can result in the presence of a thermal component, known as warm inflation. It has been found that matter with specific equation of state can also act as a candidate for warm inflation.
Article
Physics, Multidisciplinary
Sabina Yeasmin, Biswajit Deb, Atri Deshamukhya
Summary: In this work, warm inflation in the background of f (R, T) gravity under strong dissipation regime is explored. Modified field equations are derived considering scalar field for FLRW universe. Slow-roll parameters, power spectrum, and spectral indices for scalar and tensor perturbations are deduced. The study shows that both Chaotic and Natural potentials can be revived under the context of f(R, T) gravity with suitable choice of model parameters, and the results are consistent with Planck 2018 and BICEP/Keck bounds at both Planckian and sub-Planckian energy scales within the warm inflationary scenario.
CHINESE JOURNAL OF PHYSICS
(2023)
Correction
Astronomy & Astrophysics
Kim Berghaus, Peter W. Graham, David E. Kaplan
Summary: The minor mistakes in equations in section 4.1 have been corrected, and the viable parameter range of the model quoted in section 4.2 has been updated accordingly.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Subhra Bhattacharya
Summary: The article discusses the potential impact of thermal fluctuations during the inflationary period on structure formation and reheating dependence, known as warm inflation. It revisits a specific equation of state in the context of warm inflation to investigate whether such matter could serve as a viable candidate for warm inflation.
Article
Astronomy & Astrophysics
M. Laine, S. Procacci
Summary: The friction experienced by a field in a medium depends on its evolution rate compared to the medium's time scales as the medium gradually heats up. A framework is proposed to incorporate contributions from all medium time scales, with warm axion inflation used as an example. By inputting the retarded pseudoscalar correlator of a thermal Yang-Mills plasma, the system's evolution from almost vanishing temperature to entering the weak or strong regime of warm inflation is demonstrated, scrutinizing previous approximate treatments.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Multidisciplinary
Ramon Herrera, Carlos Rios
Summary: In this work, the reconstruction of an inflationary universe in the context of the gravity theory f(0)T is studied. By considering the scalar spectral index as an attractor and using the slow-roll approximation, different expressions for the reconstructed effective potential are found. The duration and temperature during the reheating epoch are analyzed, and the parameters associated with the reconstructed model are constrained by recent astronomical observations.
Article
Astronomy & Astrophysics
Yakefu Reyimuaji, Xinyi Zhang
Summary: In this study, natural inflation is considered in a warm inflation framework with temperature-dependent dissipative coefficient Gamma proportional to T-3. It is found that the Planck 2018 results prefer a weak dissipative regime for the benchmark scale f = 5M(pl), which starts in the cold regime and evolves with a growing thermal fluctuation dominating before the end of the inflation. The observed spectral tilt imposes stringent constraints on the model's parameter space, with f <1M(pl) being excluded.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Suratna Das, Rudnei O. Ramos
Summary: The next generation of cosmological observations are expected to improve the measurements of quantities related to primordial inflation in the early Universe. This paper investigates the possibility of generating large runnings in warm inflation and provides useful analytical expressions in the large dissipation regime. The results are compared and discussed for some well-motivated primordial inflaton potentials.
Article
Astronomy & Astrophysics
Orfeu Bertolami, Paulo M. Sa
Summary: Multi-field cold inflation models are usually at odds with the swampland conjectures in string theory, but can be reconciled in the strong dissipative regime of warm inflation.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Sadaf Maqsood, Abdul Jawad, Nelson Videla
Summary: By reformulating the Chaplygin warm inflationary model as an open thermodynamic system with an interacting two component fluid, this study reveals that particle production leads to an accelerated universe during inflationary era followed by a deceleration, indicating a graceful exit from inflation. The models incorporating constant and Higgs-like potential show good agreement with Planck 2018 data in weak and strong regimes, with the analysis of tensor-scalar ratio and scalar spectral behavior.
PHYSICS OF THE DARK UNIVERSE
(2021)
