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We show how observations of the density perturbation (scalar) spectrum and the gravitational wave (tensor) spectrum allow a reconstruction of the potential responsible for cosmological inflation. A complete functional reconstruction or a…

High Energy Physics - Phenomenology · Physics 2009-10-22 Edmund J. Copeland , Edward W. Kolb , Andrew R. Liddle , James E. Lidsey

Inflation elegantly provides initial conditions for the standard model of cosmology, while solving the horizon, flatness, and magnetic monopole problems. Inflationary models make predictions for the tensor-to-scalar ratio $r$ and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-12 L. Balkenhol , E. Camphuis , F. Finelli , K. Benabed , F. R. Bouchet , J. Carron , S. Galli , E. Hivon , A. R. Khalife , L. Knox , C. L. Reichardt , A. Vitrier , W. L. K. Wu

We investigate anisotropic inflation within the single-field model featuring an intermediate scale factor. Our analysis reveals that the anisotropic nature of the Friedmann equations in this framework affects the slow-roll parameters, which…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-12 Maryam Roushan , Narges Rashidi , Kourosh Nozari

Is there new physics hidden in the four-point function of the cosmic microwave background (CMB)? We conduct a detailed analysis of the Planck PR4 temperature and polarization trispectrum for $\ell\in[2,2048]$. Using the theoretical and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-30 Oliver H. E. Philcox

The original model of axion natural inflation produces a tensor-to-scalar ratio above the experimental limit. Aligned axion inflation admits inflationary trajectories that originate near a saddle point of the two-field potential, and…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-20 Federico Greco , Marco Peloso

Wave function collapse models are considered as the modified theories of standard quantum mechanics at the macroscopic level. By introducing nonlinear stochastic terms in the Schr\"odinger equation, these models make predictions,…

Quantum Physics · Physics 2017-02-02 Jing Zhang , Tiancai Zhang , Jie Li

We present a joint Bayesian analysis to impose constraints on the generalized $\alpha$-Starobinsky inflationary model using the high-precision cosmological datasets: Planck, CMB lensing from ACT DR6, and Baryon Acoustic Oscillations (BAO)…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-27 Karim Carrion , Francisco X. Linares Cedeño , Gabriel Germán , Juan Carlos Hidalgo

We examine the power-law Starobinsky model, a generalized version of the Starobinsky inflation model, characterized by a power-law correction to Einstein gravity. Employing the $f(R)$ formalism, the scalar and tensor power spectra were…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-10 Saisandri Saini , Akhilesh Nautiyal

In this work we construct a bottom-up reconstruction technique for Loop Quantum Cosmology scalar-tensor theories, from the observational indices. Particularly, the reconstruction technique is based on fixing the functional form of the…

General Relativity and Quantum Cosmology · Physics 2018-05-02 Jaume de Haro , S. D. Odintsov , V. K. Oikonomou

This proceedings contribution provides an overview of Loop Blow-up Inflation and updates its observational predictions and their comparison with the latest CMB and BAO data from combined analyses of SPT, Planck, ACT, and BICEP/Keck, as well…

High Energy Physics - Theory · Physics 2026-04-09 Sukŗti Bansal

We compare the standard single scalar field inflationary predictions with those of an inflationary phase driven by a tachyon field. A slow-roll formalism is defined for tachyon inflation and we derive the spectra of scalar and tensor…

Astrophysics · Physics 2016-11-09 Filippo Vernizzi , Daniele Steer

We explore the relationship between features in the Planck 2015 temperature and polarization data, shifts in the cosmological parameters, and features from inflation. Residuals in the temperature data at low multipole $\ell$, which are…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 Georges Obied , Cora Dvorkin , Chen Heinrich , Wayne Hu , V Miranda

Combining the stochastic and $\delta N$ formalisms, we derive non perturbative analytical expressions for all correlation functions of scalar perturbations in single-field, slow-roll inflation. The standard, classical formulas are recovered…

High Energy Physics - Theory · Physics 2016-12-01 Vincent Vennin , Alexei A. Starobinsky

The increasingly stringent observational bounds on primordial gravitational waves strongly constrain inflationary model building, favoring scenarios that predict highly suppressed tensor perturbations. While many viable constructions rely…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-11 Panagiotis G. Stavros , Spyros Basilakos , Emmanuel N. Saridakis

Recent measurements from the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT) have placed the strictest constraints on the primordial scalar perturbation spectrum, reporting a spectral index of $n_s\sim0.967-0.98$ at 95%…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-09 Qing-Yang Wang

We point out three correlated predictions of the axion monodromy inflation model: large amplitude of gravitational waves, suppression of power on horizon scales and on scales relevant for the formation of dwarf galaxies. While these…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Quinn E. Minor , Manoj Kaplinghat

Tachyon inflation is reconsidered by using the recent observational data obtained from Planck-2013 and BICEP2. The Hamilton-Jacobi formalism is picked out as a desirable approach in this work, which allows one to easily obtain the main…

General Relativity and Quantum Cosmology · Physics 2015-02-27 A. Aghamohammadi , A. Mohammadi , T. Golanbari , Kh. Saaidi

In the context of spontaneous wave function collapse models, we investigate the properties of the Continuous Spontaneous Localization (CSL) collapse rate for rigid bodies. By exploiting the Euler-Maclaurin formula, we show that for standard…

Quantum Physics · Physics 2020-10-21 Luca Ferialdi , Angelo Bassi

Defining a scale of $k$-modes of the quantum fluctuations during inflation through the dynamical horizon crossing condition $k = aH$ we go from the physical $t$ variable to $k$ variable and solve the equations of cosmological first-order…

General Relativity and Quantum Cosmology · Physics 2023-05-08 Arunoday Sarkar , Chitrak Sarkar , Buddhadeb Ghosh

In this paper, we undertake a detailed study of real scalar inflation by employing LATTICEEASY simulations to investigate preheating phenomena. Generally, the scalar inflation potential with non-minimal coupling can be approximated by a…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-15 Wei Cheng , Tong Qin , Jiujiang Jiang , Ruiyu Zhou