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Related papers: Aligned natural inflation with modulations

200 papers

We study the effect of a non-trivial vacuum prescription on warm inflation observables, namely the power spectrum of the comoving curvature perturbation. Non-trivial choice of vacuum, can provide information about trans-Planckian physics.…

General Relativity and Quantum Cosmology · Physics 2019-07-03 H. Bouzari Nezhad , F. Shojai

We consider the effects of the quantum stress tensor fluctuations of a conformal field in generating gravity waves in inflationary models. We find a non-scale invariant, non-Gaussian contribution which depends upon the total expansion…

General Relativity and Quantum Cosmology · Physics 2011-12-08 Chun-Hsien Wu , Jen-Tsung Hsiang , L. H. Ford , Kin-Wang Ng

Inflationary scenarios in string theory often involve a large number of light scalar fields, whose presence can enrich the post-inflationary evolution of primordial fluctuations generated during the inflationary epoch. We provide a simple…

High Energy Physics - Theory · Physics 2010-08-18 C. P. Burgess , M. Cicoli , M. Gomez-Reino , F. Quevedo , G. Tasinato , I. Zavala

Inflection point inflation generically includes a deviation from slow-roll when the inflaton approaches the inflection point. Such deviations are shown to be generated by transitions between singular trajectories. The effects on the power…

High Energy Physics - Theory · Physics 2013-07-22 Sean Downes , Bhaskar Dutta

We revisit models of natural inflation and show that the single-field effective theory described by the potential $V(a)\sim \cos\frac{a}{f}$ breaks down as the inflaton $a$ makes large-field excursions, even for values of $f$ smaller than…

High Energy Physics - Theory · Physics 2021-01-13 Mohamed M. Anber , Stephen Baker

We construct a natural inflation model with the inflaton as a linear combination of the fifth components of Abelian gauge fields in a five-dimensional theory. A seesaw mechanism is introduced to provide a natural milli-charge for matter…

High Energy Physics - Phenomenology · Physics 2015-06-03 Yang Bai , Ben A. Stefanek

We study the dynamics of a generalized inflationary model in which both the scalar field and its derivatives are coupled to the gravity. We consider a general form of the nonminimal derivative coupling in order to have a complete treatment…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-06 Kourosh Nozari , Narges Rashidi

We introduce a simple string model of inflation, in which the inflaton field can take trans-Planckian values while driving a period of slow-roll inflation. This leads naturally to a realisation of large field inflation, inasmuch as the…

High Energy Physics - Theory · Physics 2015-03-13 M. Cicoli , C. P. Burgess , F. Quevedo

We study the inflationary perturbations in general (classically) scale-invariant theories. Such scenario is motivated by the hierarchy problem and provides natural inflationary potentials and dark matter candidates. We analyse in detail all…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-04 Alberto Salvio

We consider natural inflation in a warm inflation framework with a temperature-dependent dissipative coefficient $\Gamma \propto T^3$. Natural inflation can be compatible with the Planck 2018 results with such warm assistance. With no a…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-05 Yakefu Reyimuaji , Xinyi Zhang

We investigate the dynamics of the recently proposed model of assisted inflation. In this model an arbitrary number of scalar fields with exponential potentials evolve towards an inflationary scaling solution, even if each of the individual…

Astrophysics · Physics 2016-08-25 Karim A. Malik , David Wands

The primordial density fluctuation inevitably couples to all forms of matter via loop corrections and depends on the ambient conditions while inflation was ongoing. This gives us an opportunity to observe processes which were in progress…

Astrophysics · Physics 2009-08-24 David Seery

I will review briefly how inflation is expected to generate a stochastic background of primordial gravitational waves (GWs). Then, I will discuss how such GWs can be enhanced by a stiff period following inflation, enough to be observable. I…

General Relativity and Quantum Cosmology · Physics 2023-08-03 Konstantinos Dimopoulos

In this work we explore the effects that a possible primordial magnetic field can have on the inflaton effective potential, taking as the underlying model a warm inflation scenario, based on global supersymmetry with a new-inflation-type…

High Energy Physics - Phenomenology · Physics 2022-08-11 Gabriella Piccinelli , Angel Sánchez

In the axion monodromy inflation, the inflation is driven by the axion with super-Planckian field values in a monomial potential with superimposed sinusoidal modulations. The coupling of the axion to massless gauge fields can induce copious…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-27 Shu-Lin Cheng , Wolung Lee , Kin-Wang Ng

By applying a particular kind of modified gravity, we study the inflation. Precisely, we extend our investigations beyond the Einstein's gravity to explore the Natural inflation model via the term $F(\phi)T$. We compute the inflation…

General Relativity and Quantum Cosmology · Physics 2025-07-30 Feyzollah Younesizadeh , Davoud Kamani

For most initial conditions, cosmologically relevant physical modes were trans-planckian at the bounce time, often by many magnitude orders. We improve the usual loop quantum cosmology calculation of the primordial power spectra -- in the…

General Relativity and Quantum Cosmology · Physics 2018-05-23 Killian Martineau , Aurélien Barrau , Julien Grain

We examine some inflationary models based on modifications of gravity in the light of Planck 2015 data, such as the generalised Chaplygin inspired inflation, models based in $N=1$ supergravity and braneworld scenarios. We also show that,…

High Energy Physics - Theory · Physics 2018-06-06 Cláudio Gomes , Orfeu Bertolami , João G. Rosa

We re-examine approximations in the analytical calculation of the primordial spectrum of cosmological perturbation produced during inflation. Taking two inflation models (chaotic inflation and natural inflation) as examples, we numerically…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. H. Huang , W. B. Lin , X. M. Zhang

The model of Natural Inflation is examined in light of recent 3-year data from the Wilkinson Microwave Anisotropy Probe and shown to provide a good fit. The inflaton potential is naturally flat due to shift symmetries, and in the simplest…

High Energy Physics - Phenomenology · Physics 2008-11-26 Christopher Savage , Katherine Freese , William H. Kinney
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