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We study the predictions of anomalous inflationary models on the abundance of structures in large scale structure observations. The anomalous features encoded in primordial curvature perturbation power spectrum are (a): localized feature in…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-30 Shant Baghram , Ali Akbar Abolhasani , Hassan Firouzjahi , Mohammad Hossein Namjoo

Inflation may provide unique insight into the physics at the highest available energy scales that cannot be replicated in any realistic terrestrial experiment. Features in the primordial power spectrum are generically predicted in a wide…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-26 Anže Slosar , Xingang Chen , Cora Dvorkin , Daniel Green , P. Daniel Meerburg , Eva Silverstein , Benjamin Wallisch

We provide a dynamical mechanism to generate localized features during inflation. The local feature is due to a sharp waterfall phase transition which is coupled to the inflaton field. The key effect is the contributions of waterfall…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Ali Akbar Abolhasani , Hassan Firouzjahi , Shahram Khosravi , Misao Sasaki

There exist several models of inflation that produce primordial bispectra that contain a large number of oscillations. In this paper we discuss these models, and aim at finding a method of detecting such bispectra in the data. We explain…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 P. Daniel Meerburg

Inflationary models predicting abundant primordial black holes (PBHs) and large amplitude of scalar-induced gravitational waves (SIGWs) often rely on amplified fluctuations over limited scales, typically driven by phase transitions,…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-15 Mohammad Hossein Namjoo , Bahar Nikbakht

We calculate the scale dependence of the bispectrum and trispectrum in (quasi) local models of non-Gaussian primordial density perturbations, and characterize this scale dependence in terms of new observable parameters. They can help to…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-12 Christian T. Byrnes , Mischa Gerstenlauer , Sami Nurmi , Gianmassimo Tasinato , David Wands

If time-dependent disruptions from slow-roll occur during inflation, the correlation functions of the primordial curvature perturbation should have scale-dependent features, a case which is marginally supported from the cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-04 Jinn-Ouk Gong , Gonzalo A. Palma , Spyros Sypsas

We study the effects of a class of features of the potential of slow-roll inflationary models corresponding to a step symmetrically dumped by an even power negative exponential factor, which we call local features. Local-type features…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-29 Alexander Gallego Cadavid , Antonio Enea Romano

By a careful implementation of gauge transformations involving long-wavelength modes, we show that a variety of effects involving squeezed bispectrum configurations, for which one Fourier mode is much shorter than the other two, cannot be…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Sabino Matarrese , Luigi Pilo , Rocco Rollo

The primordial spectrum of fluctuations may present a large peak as a result of enhancing features during inflation. This may include, but is not limited to, bumps in the inflaton's potential, phases of ultra-slow-roll or turns in…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-30 Shyam Balaji , Guillem Domenech , Joseph Silk

We analyse the efficiency of future large scale structure surveys to unveil the presence of scale dependent features in the primordial spectrum --resulting from cosmic inflation-- imprinted in the distribution of galaxies. Features may…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-04 Gonzalo A. Palma , Domenico Sapone , Spyros Sypsas

Realistic models of high-energy physics include multiple scalar fields. Renormalization requires that the fields have nonminimal couplings to the spacetime Ricci curvature scalar, and the couplings can be large at the energy scales of…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-21 David I. Kaiser , Edward A. Mazenc , Evangelos I. Sfakianakis

Next-generation galaxy and 21cm intensity mapping surveys will rely on a combination of the power spectrum and bispectrum for high-precision measurements of primordial non-Gaussianity. In turn, these measurements will allow us to…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-08 Roy Maartens , Sheean Jolicoeur , Obinna Umeh , Eline M. De Weerd , Chris Clarkson

We analyze the shape and amplitude of oscillatory features in the primordial power spectrum and non-Gaussianity induced by periodic production of heavy degrees of freedom coupled to the inflaton $\phi$. We find that non-adiabatic production…

High Energy Physics - Theory · Physics 2017-11-15 Raphael Flauger , Mehrdad Mirbabayi , Leonardo Senatore , Eva Silverstein

Long-short mode coupling during inflation, encoded in the squeezed bispectrum of curvature perturbations, induces a dependence of the local, small-scale power spectrum on long-wavelength perturbations, leading to a scale-dependent halo…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Giovanni Cabass , Enrico Pajer , Fabian Schmidt

The simplest inflationary models present us with few observable parameters to discriminate between them. A detection of features in the spectra of primordial density perturbations could provide valuable insights and lead to stringent tests…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-14 J. R. Fergusson , H. F. Gruetjen , E. P. S. Shellard , M. Liguori

We study an inflationary model driven by a single minimally coupled standard kinetic term scalar field with a step in its mass modeled by an Heaviside step function. We present an analytical approximation for the mode function of the…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-04 Frederico Arroja , Antonio Enea Romano , Misao Sasaki

The presence of additional particles during inflation leads to non-Gaussianity in late-time correlators of primordial curvature perturbations. The shape and amplitude of this signal depend on the mass and spin of the extra particles.…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-16 Azadeh Moradinezhad Dizgah , Cora Dvorkin

Sharp features in the primordial power spectrum are a powerful window into the inflationary epoch. To date, the cosmic microwave background (CMB) has offered the most sensitive avenue to search for these signatures. In this paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-27 Florian Beutler , Matteo Biagetti , Daniel Green , Anže Slosar , Benjamin Wallisch

We investigate the effects of local features in the inflationary potential on the preheating dynamics after inflation. We show that a small feature in the potential can enhance the resonance and bring the radiation-like state equation…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-28 Pankaj Saha , Yuko Urakawa