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Related papers: Inflation, Renormalization, and CMB Anisotropies

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We study the observational implications of a class of inflationary models wherein the inflaton is coupled to the Einstein tensor through a generalized non-minimal derivative coupling (GNMDC). In particular, we explore whether these models…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-03 Yashi Tiwari , Nilanjandev Bhaumik , Rajeev Kumar Jain

The nonlinear interaction between one graviton and two scalars is enhanced in specific inflationary models, potentially leading to distinguishable signatures in the bispectrum of the cosmic microwave background (CMB) anisotropies. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-15 Maresuke Shiraishi , Michele Liguori , James R. Fergusson

Standard inflationary models yield a characteristic signature of a primordial power spectrum with a red tensor and scalar tilt. Nevertheless, Cannone et al recently suggested that, by breaking the assumption of spatial diffeomorphism…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-20 Leila Graef , Robert Brandenberger

The recent measurements of temperature and polarization of Cosmic Microwave Background (CMB) have improved our understanding of the Universe and are in remarkable agreement with the $\Lambda$CDM cosmological model. However, scale dependent…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-15 Suvodip Mukherjee , Tarun Souradeep

We study the impact of (generalized) cuscuton models on standard single scalar field inflation. Generalized cuscuton models are characterized by spatial covariant gravity where a scalar degree of freedom is made non dynamical, and there are…

General Relativity and Quantum Cosmology · Physics 2022-05-10 Nicola Bartolo , Alexander Ganz , Sabino Matarrese

We reevaluate the predictions of inflation regarding primordial gravity waves, which should appear as B-modes in the CMB, in light of the fact that the standard inflationary paradigm is unable to account for the transition from an initially…

General Relativity and Quantum Cosmology · Physics 2017-11-22 Gabriel León , Abhishek Majhi , Elias Okon , Daniel Sudarsky

Supersolid inflation is a class of inflationary theories that simultaneously breaks time and space reparameterization invariance during inflation, with distinctive features for the dynamics of cosmological fluctuations. We investigate…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Angelo Ricciardone , Gianmassimo Tasinato

The inflationary potential and its derivatives determine the spectrum of scalar and tensor metric perturbations that arise from quantum fluctuations during inflation. The CBR anisotropy offers a promising means of determining the spectra of…

Astrophysics · Physics 2009-08-18 Michael Turner , Martin White

We treat a model in which tensor perturbations of de~Sitter spacetime, represented as a spatially flat model, are modified by the effects of the vacuum fluctuations of a massless conformally invariant field, such as the electromagnetic…

General Relativity and Quantum Cosmology · Physics 2011-05-05 Jen-Tsung Hsiang , L. H. Ford , Da-Shin Lee , Hoi-Lai Yu

We propose new classes of inflation models based on the modular symmetry, where the modulus field $\tau$ serves as the inflaton. We establish a connection between modular inflation and modular stabilization, wherein the modulus field rolls…

High Energy Physics - Phenomenology · Physics 2024-10-21 Gui-Jun Ding , Si-Yi Jiang , Wenbin Zhao

We argue that the non-detection of primordial tensor modes has taught us a great deal about the primordial universe. In single-field slow-roll inflation, the current upper bound on the tensor-to-scalar ratio, $r < 0.07$ $(95 \% ~CL)$,…

High Energy Physics - Theory · Physics 2017-06-21 Enrico Pajer , Guilherme L. Pimentel , Jaap V. S. Van Wijck

In principle, the tensor metric (gravity-wave) perturbations that arise in inflationary models can, beyond probing the underlying inflationary model, provide information about the Universe: ionization history, presence of a cosmological…

Astrophysics · Physics 2009-08-18 Michael S. Turner , Martin White , James E. Lidsey

Detection of the tensor perturbations predicted in inflationary models is important for testing inflation as well as for reconstructing the inflationary potential. We show that because of cosmic variance the tensor contribution to the…

Astrophysics · Physics 2009-09-25 Lloyd Knox , Michael S. Turner

We study constraints on a number of patch inflationary models in noncommutative spacetime using a compilation of recent high-precision observational data. In particular, the four-dimensional General Relativistic (GR) case, the…

Astrophysics · Physics 2007-05-23 Gianluca Calcagni , Shinji Tsujikawa

We investigate the possibility of inflation with models of antisymmetric tensor field having minimal and nonminimal couplings to gravity. Although the minimal model does not support inflation, the nonminimal models, through the introduction…

General Relativity and Quantum Cosmology · Physics 2018-11-02 Sandeep Aashish , Abhilash Padhy , Sukanta Panda , Arun Rana

The possibility to have an infinite open inflationary universe inside a bubble of a finite size is one of the most interesting realizations extensively discussed in the literature. The original idea was based on the theory of tunneling and…

Astrophysics · Physics 2009-09-29 Andrei Linde , Misao Sasaki , Takahiro Tanaka

We study a model of inflation based on $\mathcal{N}=1$ supergravity essentially depending on one effective parameter. Under a field transformation we show that this model turns out to be equivalent to a previously studied supergravity model…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-13 Gabriel Germán , Juan Carlos Hidalgo , Francisco X. Linares Cedeño , Ariadna Montiel , J. Alberto Vázquez

The observed power spectrum of the cosmic microwave background (CMB) is consistent with inflationary cosmology, which predicts a nearly scale-invariant power spectrum of quantum fluctuations of the inflaton field as they exit the Hubble…

High Energy Physics - Theory · Physics 2007-05-23 Leonard Parker

Inflation in a five-dimensional brane world model with two boundary branes is studied. We make use of the moduli space approximation whereby the low energy theory reduces to a four-dimensional biscalar-tensor gravity plus a minimally…

We consider a model of inflation consisting a triplet of $U(1)$ vector fields with the parity violating interaction which is non-minimally coupled to inflaton. The vector field sector enjoys global $O(3)$ symmetry which admits isotropic…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-16 Mohammad Ali Gorji , Seyed Ali Hosseini Mansoori , Hassan Firouzjahi
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