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We make a comprehensive investigation of the observational effect of the inflation consistency relation. We focus on the general single-field inflation model with the consistency relation $r=-8c_s n_t$, and investigate the observational…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Cheng Cheng , Qing-Guo Huang , Xiao-Dong Li , Yin-Zhe Ma

We present the constraints on inflationary parameters in a flat $\Lambda$CDM universe obtained by WMAP three year data release, plus smaller scale CMB and two LSS data sets, 2dF and SDSS (treated separately). We use a Markov Chain Monte…

Astrophysics · Physics 2009-11-11 F. Finelli , M. Rianna , N. Mandolesi

Measuring spectral distortions (SDs) of the cosmic microwave background (CMB) will provide new constraints on previously unexplored scales of the primordial power spectrum, allowing us to extend the probed parameter space by several orders…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-03 Nils Schöneberg , Matteo Lucca , Deanna C. Hooper

The possibility to have an infinite open inflationary universe inside a bubble of a finite size is one of the most interesting realizations extensively discussed in the literature. The original idea was based on the theory of tunneling and…

Astrophysics · Physics 2009-09-29 Andrei Linde , Misao Sasaki , Takahiro Tanaka

Models of inflation where the entropic directions have large and negative masses $|m_s| \gg H$ can be well described by a single-field EFT with an imaginary sound speed $c_s$. Among other features, they predict an exponential enhancement of…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-19 Ricardo Z. Ferreira

Cosmological inflation is the dominating paradigm to account for observations of the Cosmic Microwave Background (CMB). In this thesis, we study the phenomenology of a class of particularly well motivated models of inflation, known under…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-27 Stefano Orani

In this paper, we consider two case examples of Dirac-Born-Infeld (DBI) generalizations of canonical large-field inflation models, characterized by a reduced sound speed, $c_{S} < 1$. The reduced speed of sound lowers the tensor-scalar…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Nina K. Stein , William H. Kinney

It is shown that a subelectronvolt upper limit can be derived on the neutrino mass from the CMB data alone in the Lambda CDM model with the power-law adiabatic perturbations, without the aid of any other cosmological data. Assuming the…

Astrophysics · Physics 2016-08-30 Kazuhide Ichikawa , Masataka Fukugita , Masahiro Kawasaki

A new inflationary scenario whose exponential potential $V(\Phi)$ has a quadratic dependence on the field $\Phi$ in addition to the standard linear term is confronted with the tree-year observations of the Wilkinson-Microwave Anisotropy…

Astrophysics · Physics 2009-06-23 F. C. Carvalho , J. S. Alcaniz , J. A. S. Lima , R. Silva

The inflaton field responsible for inflation may not be a canonical fundamental scalar. It is possible that the inflaton is a composite of fermions or it may have a decay width. In these cases the standard procedure for calculating the…

High Energy Physics - Phenomenology · Physics 2009-09-28 Suratna Das , Subhendra Mohanty

We generalize the treatment of inflationary perturbations to deal with the non-Markovian colored noise emerging from any realistic approach to stochastic inflation. We provide a calculation of the power-spectrum of the gauge-invariant…

Astrophysics · Physics 2009-11-10 M. Liguori , S. Matarrese , M. Musso , A. Riotto

Recent observations about the cosmic microwave background evidence a clear discrepancy between the scale of inflation and the Planck scale expected in the conventional inflationary picture, based on simple chaotic inflationary models. This…

General Relativity and Quantum Cosmology · Physics 2024-12-10 Maciej Kowalczyk , Guillermo A. Mena Marugán

We describe models of single-field inflation with small and sharp step features in the potential (and sound speed) of the inflaton field, in the context of the Effective Field Theory of Inflation. This approach allows us to study the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Nicola Bartolo , Dario Cannone , Sabino Matarrese

The recent measurements of temperature and polarization of Cosmic Microwave Background (CMB) have improved our understanding of the Universe and are in remarkable agreement with the $\Lambda$CDM cosmological model. However, scale dependent…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-15 Suvodip Mukherjee , Tarun Souradeep

The inflationary cosmology paradigm is very successful in explaining the CMB anisotropy to the percent level. Besides the dependence on the inflationary model, the power spectra, spectral tilt and non-Gaussianity of the CMB temperature…

High Energy Physics - Theory · Physics 2014-02-18 Amjad Ashoorioon , Konstantinos Dimopoulos , M. M. Sheikh-Jabbari , Gary Shiu

We extend an alternative, phenomenological approach to inflation by means of an equation of state and a sound speed, both of them functions of the number of $e$-folds and four phenomenological parameters. This approach captures a number of…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-10 Stefano Gariazzo , Olga Mena , Hector Ramirez , Lotfi Boubekeur

We study here the observational constraints on single-field inflationary models achievable with the next generation of CMB experiments. We particularly focus on a Stage-IV like experiment and forecasts its constraints on inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-01 Guadalupe Cañas-Herrera , Fabrizio Renzi

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 obtain observational constraints on Randall--Sundrum type II braneworld inflation using a compilation of data including WMAP, the 2dF and latest SDSS galaxy redshift surveys. We place constraints on three classes of inflation models…

Astrophysics · Physics 2014-10-13 Shinji Tsujikawa , Andrew R. Liddle

We contrast two approaches to calculating trans-Planckian corrections to the inflationary perturbation spectrum: the New Physics Hypersurface [NPH] model, in which modes are normalized when their physical wavelength first exceeds a critical…

Astrophysics · Physics 2011-05-12 Richard Easther , William H. Kinney , Hiranya Peiris