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相关论文: Inflationary vs. Reionization Features from Planck…

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We study thermally induced density perturbations during inflation. This scenario is characterized by two thermodynamical conditions: (1) The primordial perturbations originate in the epoch when the inflationary universe contains a…

天体物理学 · 物理学 2009-10-30 Wolung Lee , Li-Zhi Fang

With Planck cosmic microwave background observations, we established the spectral amplitude and tilt of the primordial power spectrum. Evidence of a red spectral tilt ($n_\mathrm{s}=0.96$) at $8\sigma$ provides strong support for the…

宇宙学与河外天体物理 · 物理学 2020-08-18 Ivan Debono , Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

Standard inflation with one scalar field produces primordial perturbations with a nearly flat ('Harrison-Zeldovich') power spectrum. Here we consider first, a double inflation spectrum, and second, a massive scalar field with an interaction…

天体物理学 · 物理学 2016-08-30 Lutz V. Semig , Volker Mueller

Bayesian inference techniques are used to investigate situations where an additional light scalar field is present during inflation and reheating. This includes (but is not limited to) curvaton-type models. We design a numerical pipeline…

宇宙学与河外天体物理 · 物理学 2017-09-13 Vincent Vennin , Kazuya Koyama , David Wands

In the previous work, a new kind of inflation model was proposed, which has the interesting property that its perturbation equation of motion gets a correction of k^4, due to the non-linearity of the kinetic term. Nonetheless, the…

宇宙学与河外天体物理 · 物理学 2018-03-16 Jun Chen , Hou Wenjie , Defu Hou , Taotao Qiu

We derive the first systematic observational constraints on reheating in models of inflation where an additional light scalar field contributes to primordial density perturbations and affects the expansion history during reheating. This…

宇宙学与河外天体物理 · 物理学 2017-01-19 Robert J. Hardwick , Vincent Vennin , Kazuya Koyama , David Wands

In this work, we examine cosmological constraints on models of composite inflation based on the slow-roll approximation by using the recent Planck measurement. We compare the spectral index of curvature perturbation (and its running) and…

高能物理 - 唯象学 · 物理学 2016-06-30 Phongpichit Channuie

The first year of observations by the Planck satellite mission shows that the cosmic microwave background (CMB) fluctuations are consistent with gaussian statistics in the primordial perturbations, a key prediction of the simplest models of…

宇宙学与河外天体物理 · 物理学 2015-10-19 Ana Achucarro , Vicente Atal , Pablo Ortiz , Jesus Torrado

We analyze the limits on resonant particle production during inflation based upon the power spectrum of fluctuations in matter and the cosmic microwave background. We show that such a model is consistent with features observed in the matter…

天体物理学 · 物理学 2009-11-10 G. J. Mathews , D. J. H. Chung , K. Ichiki , T. Kajino , M. Orito

We study inflationary constraints from reheating on two classes of single-field inflationary models: a generalized $\alpha$-attractor with potential $V(\phi) = V_0 \!\left(1 - \sech^p\!\left[\phi/(\sqrt{6\alpha}\,M_{Pl})\right]\right)$ and…

宇宙学与河外天体物理 · 物理学 2025-11-26 Gabriel German , Juan Carlos Hidalgo

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…

天体物理学 · 物理学 2014-11-18 Rajeev Kumar Jain , Pravabati Chingangbam , Jinn-Ouk Gong , L. Sriramkumar , Tarun Souradeep

Recently, it has been realized that the so-called G-inflation model inspired by supplementing a generalized covariant Galileon-like non-linear derivative self-interacting term to the standard kinetic term should be ruled out from…

广义相对论与量子宇宙学 · 物理学 2017-12-06 Maysam Motaharfar , Erfan Massaeli , Hamid Reza Sepangi

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…

宇宙学与河外天体物理 · 物理学 2018-12-05 Akhilesh Nautiyal

With the Planck 2015 result, most of the well known canonical large field inflation models turned out to be strongly disfavored. Axion inflation is one of such models which is becoming marginalized with the increasing precession of CMB…

高能物理 - 唯象学 · 物理学 2018-08-02 Debaprasad Maity , Pankaj Saha

In this work we introduce a new plateau-like inflationary model including a quadratic scalar potential coupled non-minimally to gravity. This potential has a dominant constant energy density at early times which can realize successful…

高能物理 - 理论 · 物理学 2015-11-30 Mehdi Eshaghi , Moslem Zarei , Nematollah Riazi , Ahmad Kiasatpour

The effect of the length of inflation on the power spectra of scalar and tensor perturbations is estimated using the power-law inflation model with a scale factor of a(t) = t^q. Considering various pre-inflation models with…

天体物理学 · 物理学 2007-05-23 Shiro Hirai , Tomoyuki Takami

We study the two-field warm inflation models with a double quadratic potential and a linear temperature dependent dissipative coefficient. We derived the evolution equation of all kinds of perturbations without assuming slow-roll…

广义相对论与量子宇宙学 · 物理学 2019-05-23 Yang-yang Wang , Xiao-Min Zhang , Jian-Yang Zhu

The power spectrum of M-theory cascade inflation is derived. It possesses three distinctive signatures: a decisive power suppression at small scales, oscillations around the scales that cross the horizon when the inflaton potential jumps…

高能物理 - 理论 · 物理学 2007-05-23 Amjad Ashoorioon , Axel Krause

There has been much recent discussion, and some confusion, regarding the use of existing observational data to estimate the likelihood that next-generation cosmic microwave background (CMB) polarization experiments might detect a nonzero…

天体物理学 · 物理学 2024-03-13 Wessel Valkenburg , Lawrence M. Krauss , Jan Hamann

Recent BICEP/Keck data on the cosmic microwave background, in combination with previous WMAP and Planck data, impose strong new constraints on the tilt in the scalar perturbation spectrum, $n_s$, as well as the tensor-to-scalar ratio, $r$.…

高能物理 - 唯象学 · 物理学 2022-02-16 John Ellis , Marcos A. G. Garcia , Dimitri V. Nanopoulos , Keith A. Olive , Sarunas Verner