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相关论文: A Cosmological Tachyon Collider: Enhancing the Lon…

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We present and examine a kinetically coupled tachyon dark energy model, where a tachyon scalar field interacts with the matter sector. More specifically, we deduce this cosmological setting from a generalised interacting dark energy model…

广义相对论与量子宇宙学 · 物理学 2024-12-31 Francesco Pace , Alberto Rozas-Fernández , Özgen Tunç Türker

We investigate the possibility that a heavy scalar field, whose mass exceeds the Hubble scale during inflation, could leave non-negligible signatures in the Cosmic Microwave Background (CMB) temperature anisotropy power spectrum through the…

宇宙学与河外天体物理 · 物理学 2015-06-05 Ryo Saito , Masahiro Nakashima , Yu-ichi Takamizu , Jun'ichi Yokoyama

In a model of spontaneous scalarization of neutron stars proposed by Damour and Esposite-Farese, a general relativistic branch becomes unstable to trigger tachyonic growth of a scalar field $\phi$ toward a scalarized branch. Applying this…

广义相对论与量子宇宙学 · 物理学 2023-02-13 Ratchaphat Nakarachinda , Sirachak Panpanich , Shinji Tsujikawa , Pitayuth Wongjun

Current bounds on the tensor-to-scalar ratio imply that the energy scale of inflation may lie below the grand-unified scale. In this paper, we show that in a broad class of single-field inflation models with sufficiently small energy…

高能物理 - 唯象学 · 物理学 2026-02-18 Haruto Masubuchi , Yuma Narita , Wen Yin

Tensor non-Gaussianity represents an important future probe of the physics of inflation. Inspired by recent works, we elaborate further on the possibility of significant primordial tensor non-Gaussianities sourced by extra fields during…

宇宙学与河外天体物理 · 物理学 2019-02-20 Emanuela Dimastrogiovanni , Matteo Fasiello , Gianmassimo Tasinato , David Wands

We calculate the tensor bispectrum mediated by an excited scalar field during inflation and find that the bispectrum peaks in the squeezed configuration, which is different from that of gravitational waves induced by enhanced curvature…

宇宙学与河外天体物理 · 物理学 2024-09-06 Zhi-Zhang Peng , Cheng-Jun Fang , Zong-Kuan Guo

We investigate warm inflationary scenario in which the accelerated expansion of the early Universe is driven by chameleon-like scalar fields. Due to the non-minimal coupling between the scalar field and the matter sector, the…

We probe the cosmological consequences of a recently proposed class of solutions to the cosmological constant problem. In these models, the universe undergoes a long period of inflation followed by a contraction and a bounce that sets the…

高能物理 - 唯象学 · 物理学 2022-01-27 Lingyuan Ji , David E. Kaplan , Surjeet Rajendran , Erwin H. Tanin

The increasing precision of cosmological datasets is opening up new opportunities to test predictions from cosmic inflation. Here we study the impact of high precision constraints on the primordial power spectrum and show how a new…

天体物理学 · 物理学 2010-04-08 Benjamin Gold , Andreas Albrecht

The capability of Cosmic Inflation to explain the latest Cosmic Microwave Background and Baryonic Acoustic Oscillation data is assessed by performing Bayesian model comparison within the landscape of nearly three-hundred models of…

宇宙学与河外天体物理 · 物理学 2024-08-27 Jerome Martin , Christophe Ringeval , Vincent Vennin

The emergent model in the context of loop quantum cosmology with a tachyon scalar field is studied. We find that there is a center equilibrium point in the semiclassical region and a saddle point in the classical region. If the potential of…

宇宙学与河外天体物理 · 物理学 2010-05-28 Puxun Wu , Shuang Nan Zhang , Hongwei Yu

Features in the inflationary landscape can inject extra energies to inflation models and produce on-shell particles with masses much larger than the Hubble scale of inflation. This possibility extends the energy reach of the program of…

高能物理 - 唯象学 · 物理学 2022-09-02 Xingang Chen , Reza Ebadi , Soubhik Kumar

Inflationary cosmology proposes that the early Universe undergoes accelerated expansion, driven, in simple scenarios, by a single scalar field, or inflaton. The form of the inflaton potential determines the initial spectra of density…

宇宙学与河外天体物理 · 物理学 2022-09-21 Richard Easther , Benedict Bahr-Kalus , David Parkinson

We investigate a string-inspired dark energy scenario featuring a scalar field with a coupling to the Gauss-Bonnet invariant. Such coupling can trigger the onset of late dark energy domination after a scaling matter era. The universe may…

高能物理 - 理论 · 物理学 2008-11-26 Tomi Koivisto , David F. Mota

We provide a formula for the scaling behaviour of the inflationary bispectrum in the 'squeezed' limit where one momentum becomes much smaller than the other two. This determines the scaling of the halo bias at low wavenumber and will be an…

宇宙学与河外天体物理 · 物理学 2013-05-30 Mafalda Dias , Raquel H. Ribeiro , David Seery

A scenario with two subsequent periods of inflationary expansion in the very early universe is examined. The model is based on a potential motivated by symmetries being found in field theory at high energy. For various parameter sets of the…

宇宙学与河外天体物理 · 物理学 2016-01-13 Simon Schettler , Jurgen Schaffner-Bielich

We show that inflationary models with broken rotational invariance generate testable off-diagonal signatures in the correlation between the $\mu$-type distortion and temperature fluctuations of the cosmic microwave background. More…

宇宙学与河外天体物理 · 物理学 2015-10-07 Maresuke Shiraishi , Michele Liguori , Nicola Bartolo , Sabino Matarrese

The apparent alignment of the cosmic microwave background multipoles on large scales challenges the standard cosmological model. Scalar field inflation is isotropic and cannot account for the observed alignment. We explore the imprints, a…

天体物理学 · 物理学 2010-04-14 Christian G. Boehmer , David F. Mota

The epoch when the Universe had a temperature higher than a GeV is long before any time at which we have reliable observations constraining the cosmological evolution. For example, the occurrence of a second burst of inflation (sometimes…

广义相对论与量子宇宙学 · 物理学 2009-10-31 Luis E Mendes , Andrew R Liddle

[Abridged] A sharp cut-off in the primordial scalar power spectrum on large scales has been known to improve the fit to the cosmic microwave background (CMB) data when compared to the more standard, nearly scale invariant power spectrum…

宇宙学与河外天体物理 · 物理学 2022-08-11 H. V. Ragavendra , Debika Chowdhury , L. Sriramkumar