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Related papers: No-boundary wave function for two-field inflation

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Heavy isocurvature fields may have a strong influence on the low energy dynamics of curvature perturbations during inflation, as long as the inflationary trajectory becomes non-geodesic in the multi-field target space (the landscape). If…

High Energy Physics - Theory · Physics 2016-02-22 Sebastian Cespedes , Gonzalo A. Palma

I study the "general" case that arises in the Extended Effective Field Theory of Inflation (gEEFToI), in which the coefficients of the sixth order polynomial dispersion relation depend on the physical wavelength of the fluctuation mode,…

High Energy Physics - Theory · Physics 2018-12-05 Amjad Ashoorioon

We propose a novel mechanism for significantly enhancing the amplitude of primordial electromagnetic fields during inflation. Similar to existing proposals, our idea is based on parametric resonance effects due to…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-03 Misao Sasaki , Valeri Vardanyan , Vicharit Yingcharoenrat

We investigate the extent to which the Swampland Conjecture can be employed to constrain large-field inflationary models from the perspective of quantum gravity consistency. In particular, we focus on the Swampland Distance Conjecture,…

High Energy Physics - Theory · Physics 2025-11-07 Yuma S. Furuta , Yuta Hamada , Kazunori Kohri

We study inflation and late-time acceleration in the expansion of the universe in non-minimal electromagnetism, in which the electromagnetic field couples to the scalar curvature function. It is shown that power-law inflation can be…

Astrophysics · Physics 2009-06-23 Kazuharu Bamba , Sergei D. Odintsov

Massive fields during inflation provide an interesting opportunity to test new physics at very high energy scales. Meanwhile in fundamental realizations, the inflationary field space typically has a curved geometry, which may leave…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-23 Dong-Gang Wang

The dynamics of hybrid models is usually approximated by the evolution of a scalar field slowly rolling along a nearly flat valley. Inflation ends with a waterfall phase, due to a tachyonic instability. This final phase is usually assumed…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-27 Sébastien Clesse

We derive an extended version of the well-known Lyth Bound on the total variation of the inflaton field, incorporating higher order corrections in slow roll. We connect the field variation $\Delta\phi$ to both the spectral index of scalar…

Astrophysics · Physics 2009-11-11 Richard Easther , William H. Kinney , Brian A. Powell

A class of non-canonical inflationary models is identified, where the leading-order contribution to the non-Gaussianity of the curvature perturbation is determined by the sound speed of the fluctuations in the inflaton field. Included in…

High Energy Physics - Theory · Physics 2008-11-26 Ian Huston , James E. Lidsey , Steven Thomas , John Ward

We present a novel inflationary scenario in theories with low scale (TeV) quantum gravity, in which the standard model particles are localized on the branes whereas gravity propagates in the bulk of large extra dimensions. This inflationary…

High Energy Physics - Phenomenology · Physics 2009-10-31 Gia Dvali , S. -H. Henry Tye

It has become standard practice to take the logarithmic growth of the scale factor as a measure of the amount of inflation, despite the well-known fact that this is only an approximation for the true amount of inflation required to solve…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-02 Sirichai Chongchitnan

We show that the non-linear evolution of long wavelength perturbations may be important in a wide class of inflationary scenarios. We develop a solution for the evolution of such nonlinear perturbations which is exact to first order in a…

General Relativity and Quantum Cosmology · Physics 2009-08-29 Niayesh Afshordi , Robert Brandenberger

Warm inflation is examined in a multi-field model. Solutions are obtained for expansion e-folds and scalar density perturbations. Nonequilibrium dynamics is restricted to a regime that is displaced only slightly from thermal equilibrium and…

High Energy Physics - Phenomenology · Physics 2009-10-31 Arjun Berera

We carry out numerical investigations of the dynamics and perturbations in the Nflation model of Dimopoulos et al. (2005). This model features large numbers of scalar fields with different masses, which can cooperate to drive inflation…

Astrophysics · Physics 2009-11-11 Soo A Kim , Andrew R Liddle

We study the dynamics of two-field models of inflation characterized by a hierarchy of masses between curvature and isocurvature modes. When the hierarchy is large, a low energy effective field theory (EFT) exists in which only curvature…

High Energy Physics - Theory · Physics 2015-06-03 Sebastian Cespedes , Vicente Atal , Gonzalo A. Palma

In the context of two-field inflation characterized by a light direction and a heavy direction, we revisit the question of the impact of the massive modes on the power spectrum produced after a turn in the inflationary trajectory. We…

High Energy Physics - Theory · Physics 2014-03-04 Xian Gao , David Langlois , Shuntaro Mizuno

Quantization implies independent degrees of freedom that do not appear in the classical theory, given by fluctuations, correlations, and higher moments of a state. A systematic derivation of the resulting dynamical systems is presented here…

High Energy Physics - Theory · Physics 2021-08-24 Martin Bojowald , Suddhasattwa Brahma , Sean Crowe , Ding Ding , Joseph McCracken

We draw attention to the possibility that inflation (i.e. accelerated expansion) might continue after the end of slow roll, during a period of fast oscillations of the inflaton field \phi . This phenomenon takes place when a mild…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Thibault Damour , Viatcheslav F. Mukhanov

We explore inflation via the effective potential of the minimal Wess-Zumino model, considering both the real and imaginary components of the complex field. Using transport techniques, we calculate the full allowed range of $n_s$, $r$ and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 John Ellis , Nick E. Mavromatos , David J. Mulryne

We investigate the dynamics of single and multiple scalar fields with exponential potentials, leading to power-law and assisted inflation, in loop quantum cosmology. Unlike in the classical theory, dynamical trajectories in loop quantum…

General Relativity and Quantum Cosmology · Physics 2012-07-05 Evan Ranken , Parampreet Singh