English
Related papers

Related papers: Revisiting Loop Corrections in Single Field USR In…

200 papers

We study the behaviour of inflationary density perturbations in the vicinity of horizon crossing, using numerical evolution of the relevant mode equations. We explore two specific scenarios. In one, inflation is temporarily ended because a…

Astrophysics · Physics 2009-10-31 Samuel M Leach , Andrew R Liddle

We study multifield contributions to the scalar power spectrum in an ensemble of six-field inflationary models obtained in string theory. We identify examples in which inflation occurs by chance, near an approximate inflection point, and we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Liam McAllister , Sébastien Renaux-Petel , Gang Xu

Probing correlations among short and long-wavelength cosmological fluctuations is known to be decisive for deepening the current understanding of inflation at the microphysical level. Spectral distortions of the CMB can be caused by…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Emanuela Dimastrogiovanni , Razieh Emami

We compute the bispectrum of primordial density perturbations in CMB to second order in the slow-roll parameters of single field inflation. We correct previous results and found that next-to-leading order corrections can be of the same…

High Energy Physics - Theory · Physics 2026-03-31 Ignatios Antoniadis , Auttakit Chatrabhuti , Jules Cunat , Hiroshi Isono

We point out that if quantum field renormalization is taken into account the predictions of slow-roll inflation for both the scalar and tensorial power spectra change significantly for wavelengths that today are at observable scales

Cosmology and Nongalactic Astrophysics · Physics 2010-05-18 Ivan Agullo , Jose Navarro-Salas , Gonzalo J. Olmo , Leonard Parker

One-loop correction to the power spectrum in generic single-field inflation is calculated by using standard perturbation theory. Because of the enhancement inversely proportional to the observed red tilt of the spectral index of curvature…

High Energy Physics - Theory · Physics 2022-02-11 Jason Kristiano , Jun'ichi Yokoyama

Recently, there are several reports that the cosmic magnetic fields on Mpc scale in void region is larger than $\sim 10^{-15}$G with an uncertainty of a few orders from the current blazar observations. On the other hand, in inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Tomohiro Fujita , Shuichiro Yokoyama

We consider the backreaction of the long wavelength tensor modes produced during a slow-roll inflationary regime driven by a single scalar field in a spatially flat Friedmann-Lema\^{\i}tre-Robertson-Walker background geometry. We…

General Relativity and Quantum Cosmology · Physics 2014-08-27 G. Marozzi , G. P. Vacca

We explore the consequences of the existence of a very large number of light scalar degrees of freedom in the early universe. We distinguish between participator and spectator fields. The former have a small mass, and can contribute to the…

High Energy Physics - Theory · Physics 2009-05-11 Peter Adshead , Richard Easther , Eugene A. Lim

We study 1-loop corrections to the primordial stochastic background of gravitational waves produced during inflation. While in single-clock, at the leading order in slow-roll, quantum corrections keep the amplitude scale-free this is not…

High Energy Physics - Theory · Physics 2022-02-11 Denis Comelli , Maicol Di Giambattista , Luigi Pilo , Rocco Rollo

We derive analytic bounds on the shape of the primordial power spectrum in the context of single-field inflation. In particular, the steepest possible growth has a spectral index of $n_s - 1 = 4$ once transients have died down. Its primary…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-24 Christian T. Byrnes , Philippa S. Cole , Subodh P. Patil

We constrain the spectrum of primordial curvature perturbations by using recent Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) data. Specifically, we consider CMB data from the COBE, Boomerang and Maxima experiments, the…

Astrophysics · Physics 2009-11-06 S. Hannestad , S. H. Hansen , F. L. Villante , A. J. S. Hamilton

We present a consistent one-loop calculation for the inflationary tensor power spectrum in the presence of an excited spectator scalar field using the in-in formalism. We find that the super-horizon primordial power spectrum of the tensor…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-24 Atsuhisa Ota , Misao Sasaki , Yi Wang

We investigate the impact of one-loop radiative corrections in a non-supersymmetric model of hybrid inflation with a chaotic (polynomial-like) potential,$V(\phi) = V_0 + \lambda_p \phi^p$, in the light of the latest constraints from…

High Energy Physics - Phenomenology · Physics 2026-03-17 Waqas Ahmed , Saleh O. Allehabi , Mansoor Ur Rehman

In this paper we apply the usual perturbative methodology to evaluate the one-loop effective potential in a nonlocal scalar field theory. We find that the effect induced by the nonlocaliity of the theory is always very small and we discuss…

General Relativity and Quantum Cosmology · Physics 2015-11-18 F. Briscese , E. R. Bezerra de Mello , A. Yu. Petrov , V. B. Bezerra

Primordial magnetic fields are generated during inflation by considering actions that break the conformal invariance of the electromagnetic field. To break the conformal invariance, the electromagnetic fields are coupled either to the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 Sagarika Tripathy , Debika Chowdhury , Rajeev Kumar Jain , L. Sriramkumar

We use the power-counting formalism of effective field theory to study the size of loop corrections in theories of slow-roll inflation, with the aim of more precisely identifying the limits of validity of the usual classical inflationary…

High Energy Physics - Phenomenology · Physics 2009-10-17 C. P. Burgess , Hyun Min Lee , Michael Trott

We investigate the validity of effective field theory methods and the decoupling of heavy fields during inflation. Considering models of inflation in which the inflaton is coupled to a heavy (super-Hubble) degree of freedom initially in its…

We construct a model of inflation based on a low-energy effective theory of spontaneously broken global scale invariance. This provides a shift symmetry that protects the inflaton potential from quantum corrections. Since the underlying…

High Energy Physics - Theory · Physics 2014-10-22 Csaba Csaki , Nemanja Kaloper , Javi Serra , John Terning

Single field models of inflation capable to produce primordial black holes usually require a significant departure from the standard, perturbative slow-roll regime. In fact, in many of these scenarios, the size of the slow-roll parameter…

High Energy Physics - Theory · Physics 2023-08-08 Gianmassimo Tasinato