scholarly journals GRAVITATIONAL WAVES FROM THE EARLY UNIVERSE

2004 ◽  
pp. 855-892
Author(s):  
ALESSANDRA BUONANNO
Keyword(s):  
Gravitational Waves ◽  
Early Universe

Gravitational waves: A probe to the physics in the early universe

2015 ◽  
Vol 30 (28n29) ◽  
pp. 1545005
Author(s):  
Qing-Guo Huang
Keyword(s):  
Quantum Theory ◽  
Gravitational Waves ◽  
Early Universe ◽  
Upper Bound ◽  
Planck Scale ◽  
Big Bang ◽  
Planck Data ◽  
Inflationary Scenario ◽  
Fundamental Scale ◽  
The Big Bang

Gravitational waves can escape from the big bang and can be taken as a probe to the physics, in particular the inflation, in the early universe. Planck scale is a fundamental scale for quantum theory of gravity. Requiring the excursion distance of inflaton in the field space during inflation yields an upper bound on the tensor-to-scalar ratio. For example, [Formula: see text] for [Formula: see text]. In the typical inflationary scenario, we predict [Formula: see text] and [Formula: see text] which are consistent with Planck data released in 2015 quite well. Subtracting the contribution of thermal dust measured by Planck, BICEP2 data implies [Formula: see text] which is the tightest bound on the tensor-to-scalar ratio from current experiments.

scholarly journals Magnetism in the Early Universe

2018 ◽  
Vol 14 (A30) ◽  
pp. 295-298
Author(s):  
Tina Kahniashvili ◽  
Axel Brandenburg ◽  
Arthur Kosowsky ◽  
Sayan Mandal ◽  
Alberto Roper Pol
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Gravitational Waves ◽  
Early Universe ◽  
Large Scale ◽  
Direct Detection ◽  
Correlation Lengths ◽  
Cosmological Scenario ◽  
Expansion Of The Universe ◽  
The Universe

AbstractBlazar observations point toward the possible presence of magnetic fields over intergalactic scales of the order of up to ∼1 Mpc, with strengths of at least ∼10−16 G. Understanding the origin of these large-scale magnetic fields is a challenge for modern astrophysics. Here we discuss the cosmological scenario, focussing on the following questions: (i) How and when was this magnetic field generated? (ii) How does it evolve during the expansion of the universe? (iii) Are the amplitude and statistical properties of this field such that they can explain the strengths and correlation lengths of observed magnetic fields? We also discuss the possibility of observing primordial turbulence through direct detection of stochastic gravitational waves in the mHz range accessible to LISA.

scholarly journals Turbulence of Weak Gravitational Waves in the Early Universe

2017 ◽  
Vol 119 (22) ◽  
Author(s):  
Sébastien Galtier ◽  
Sergey V. Nazarenko
Keyword(s):  
Gravitational Waves ◽  
Early Universe

scholarly journals Inflationary gravitational waves and the evolution of the early universe

2014 ◽  
Vol 2014 (01) ◽  
pp. 040-040 ◽  
Author(s):  
Ryusuke Jinno ◽  
Takeo Moroi ◽  
Kazunori Nakayama
Keyword(s):  
Gravitational Waves ◽  
Early Universe

scholarly journals INFLATION, QUANTUM FIELDS, AND CMB ANISOTROPIES

2009 ◽  
Vol 18 (14) ◽  
pp. 2329-2335 ◽  
Author(s):  
IVÁN AGULLÓ ◽  
JOSÉ NAVARRO-SALAS ◽  
GONZALO J. OLMO ◽  
LEONARD PARKER
Keyword(s):  
Cosmic Microwave Background ◽  
Gravitational Waves ◽  
Early Universe ◽  
Inflationary Cosmology ◽  
Quantum Field ◽  
Quantum Fields ◽  
Microwave Background ◽  
Cosmological Inflation ◽  
Near Future ◽  
Field Renormalization

Inflationary cosmology has proven to be the most successful at predicting the properties of the anisotropies observed in the cosmic microwave background (CMB). In this essay we show that quantum field renormalization significantly influences the generation of primordial perturbations and hence the expected measurable imprint of cosmological inflation on the CMB. However, the new predictions remain in agreement with observation, and in fact favor the simplest forms of inflation. In the near future, observations of the influence of gravitational waves from the early universe on the CMB will test our new predictions.

scholarly journals Numerical simulations of gravitational waves from early-universe turbulence

2020 ◽  
Vol 102 (8) ◽  
Author(s):  
Alberto Roper Pol ◽  
Sayan Mandal ◽  
Axel Brandenburg ◽  
Tina Kahniashvili ◽  
Arthur Kosowsky
Keyword(s):  
Numerical Simulations ◽  
Gravitational Waves ◽  
Early Universe

scholarly journals CMB anisotropy science: a review

2012 ◽  
Vol 8 (S288) ◽  
pp. 42-52 ◽  
Author(s):  
Anthony Challinor
Keyword(s):  
Dark Matter ◽  
Cosmological Model ◽  
Cosmic Microwave Background ◽  
Gravitational Waves ◽  
Early Universe ◽  
Critical Role ◽  
Microwave Background ◽  
Fundamental Physics ◽  
Standard Cosmological Model

AbstractThe cosmic microwave background (CMB) provides us with our most direct observational window to the early universe. Observations of the temperature and polarization anisotropies in the CMB have played a critical role in defining the now-standard cosmological model. In this contribution we review some of the basics of CMB science, highlighting the role of observations made with ground-based and balloon-borne Antarctic telescopes. Most of the ingredients of the standard cosmological model are poorly understood in terms of fundamental physics. We discuss how current and future CMB observations can address some of these issues, focusing on two directly relevant for Antarctic programmes: searching for gravitational waves from inflation via B-mode polarization, and mapping dark matter through CMB lensing.

scholarly journals FLUCTUATION SPECTRUM FROM A SCALAR-TENSOR BIMETRIC GRAVITY THEORY

2003 ◽  
Vol 12 (04) ◽  
pp. 697-712 ◽  
Author(s):  
M. A. CLAYTON ◽  
J. W. MOFFAT
Keyword(s):  
Scalar Field ◽  
Gravitational Waves ◽  
Early Universe ◽  
Initial Period ◽  
Field Potential ◽  
Gravity Theory ◽  
Fluctuation Spectrum ◽  
Quadratic Potential ◽  
Initial Values ◽  
Bimetric Gravity

Predictions of the CMB spectrum from a bimetric gravity theory (BGT)1 are presented. The initial inflationary period in BGT is driven by a vanishingly small speed of gravitational waves vg in the very early universe. This initial inflationary period is insensitive to the choice of scalar field potential and initial values of the scalar field. After this initial period of inflation, vg will increase rapidly and the effects of a potential will become important. We show that a quadratic potential introduced into BGT yields an approximately flat spectrum with inflation parameters: ns=0.98, nt=-0.027, αs=-3.2×10-4 and αt=-5.0×10-4, with r ≥ 0.014.

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