Primordial Gravitational Waves and Cosmology

  title={Primordial Gravitational Waves and Cosmology},
  author={Lawrence Krauss and Scott Dodelson and Stephan Meyer},
  pages={989 - 992}
Astronomical Inflation In astronomy, according to the theory of inflation, the universe underwent a period of extremely accelerated expansion when it was only a fraction of a second old. This process made the universe flat, isotropic, and homogeneous, and it explains how quantum mechanical seeds developed into the large-scale structure we observe today. The theory also predicts that gravitational waves were produced during the early inflationary phase. Alternative theories either predict no… 
Primordial Gravitational Waves from Cosmic Inflation
Cosmic inflation generates primordial gravitational waves (PGWs) through the same physical process that seeds all structure formation in the observable universe. We will demonstrate this mechanism in
Peering Back to the Beginning of Time
Inflation—the hypothesis that the Universe underwent a phase of superluminal expansion in a brief period following the big bang—has the potential of explaining, from first principles, why the
Cosmological and astrophysical observables from field theory in curved backgrounds
The framework of effective field theory has provided valuable insights needed to understand the evolution of physical systems at different energy scales. In particular, when comparing the
Polarized primordial gravitational waves in the ghost-free parity-violating gravity
The tests of parity symmetry in the gravitational interaction is an attractive issue in gravitational-wave astronomy. In the general theories of gravity with parity violation, one of the fundamental
Measuring Inflation with CLASS
Using the Cosmology Large Angular Scale Surveyor (CLASS), we will measure the polarization of the Cosmic Microwave Background (CMB) to constrain inflationary theory. The gravitational waves generated
Modifications to gravitational wave equation from canonical quantum gravity
It is expected that the quantum nature of spacetime leaves its imprint in all semiclassical gravitational systems, at least in certain regimes, including gravitational waves. In this paper we
A New Theoretical Technique for the Measurement of High-Frequency Relic Gravitational Waves
Under most models of the early universe evolution, high-frequency gravitational waves (HFGWs) were produced. They are referred to as “relic” high-frequency gravitational waves or HFRGWs and their
Gravitational Waves: Present Status and Future Prospectus
Remarkable progress has been made during recent years on the development of gravitational wave detectors. The review describes the present status and future prospectus of the gravitational wave
Galactically inertial space probes for the direct measurement of the metric expansion of the universe
Astrometric data from the future GAIA and OBSS missions will allow a more precise calculation of the local galactic circular speed, and better measurements of galactic movements relative to the CMB


Grand unification, gravitational waves, and the cosmic microwave background anisotropy.
The stochastic gravitational wave background resulting from inflation and its effect on the cosmic microwave background radiation (CMBR) is reexamine and the energy density associated with gravitational waves from inflation is examined.
Three-point statistics of cosmological stochastic gravitational waves
We consider the three-point function (i.e. the bispectrum or non-Gaussianity) for stochastic backgrounds of gravitational waves. We estimate the amplitude of this signal for the primordial
Study of the Experimental Probe of Inflationary Cosmology (EPIC)-Intemediate Mission for NASA's Einstein Inflation Probe
Measurements of Cosmic Microwave Background (CMB) anisotropy have served as the best experimental probe of the early universe to date. The inflationary paradigm, inspired in part by the extreme
Coherent phase argument for inflation
Cosmologists have developed a phenomenally successful picture of structure in the universe based on the idea that the universe expanded exponentially in its earliest moments. There are three pieces
Causality and Primordial Tensor Modes
We introduce the real space correlation function of B-mode polarization of the cosmic microwave background (CMB) as a probe of superhorizon tensor perturbations created by inflation. By causality,
Inflationary universe: A possible solution to the horizon and flatness problems
The standard model of hot big-bang cosmology requires initial conditions which are problematic in two ways: (1) The early universe is assumed to be highly homogeneous, in spite of the fact that
Gravitational lensing effect on cosmic microwave background polarization
We investigate the effect of gravitational lensing by matter distribution in the universe on the cosmic microwave background polarization power spectra and temperature-polarization cross-correlation
Nearly scale invariant spectrum of gravitational radiation from global phase transitions.
Using a large N sigma model approximation, the power spectrum of gravitational waves arising from a global phase transition in the early Universe is calculated and it is confirmed that it is scale invariant, implying an observation of such a spectrum may not be a unique feature of inflation.