Probing the early universe with inflationary gravitational waves
- 5 March 2008
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review D
- Vol. 77 (6), 063504
- https://doi.org/10.1103/physrevd.77.063504
Abstract
Near comoving wave number , the gravitational-wave background (GWB) from inflation carries information about the physical conditions near two moments in cosmic history: the moment when “left the horizon” during inflation, and the moment when it “re-entered the horizon” after inflation. We investigate the extent to which this information can be extracted if the GWB is measured by a combination of cosmic-microwave-background polarization experiments on large scales and space-based laser-interferometer experiments on small scales. To disentangle this information, we derive a new gravitational-wave transfer function that incorporates a number of physical effects that were treated less accurately, less generally, or were missing altogether in previous treatments. In particular, it incorporates: (i) dark energy with time-varying equation of state ; (ii) tensor anisotropic stress due to free-streaming relativistic particles in the early universe; and (iii) a variety of physical effects that cause deviations from the standard equation of state during the radiation era. Based on this transfer function, we consider the degree to which the GWB can be used to test inflation and to probe the “primordial dark age” between the end of inflation and the electroweak phase transition.
Keywords
This publication has 51 references indexed in Scilit:
- Stochastic gravitational wave production after inflationJournal of Cosmology and Astroparticle Physics, 2006
- Detecting the cosmic gravitational wave background with the Big Bang ObserverClassical and Quantum Gravity, 2006
- “Graceful” old inflationPhysical Review D, 2006
- Comment on “Damping of tensor modes in cosmology”Physical Review D, 2005
- Gravitational BaryogenesisPhysical Review Letters, 2004
- Relic gravitational waves produced after preheatingPhysical Review D, 1997
- Cosmological evolution of scale-invariant gravity wavesPhysical Review D, 1995
- Random and correlated phases of primordial gravitational wavesPhysical Review D, 1995
- The collisionless damping of density fluctuations in an expanding universeThe Astrophysical Journal, 1983
- A new inflationary universe scenario: A possible solution of the horizon, flatness, homogeneity, isotropy and primordial monopole problemsPhysics Letters B, 1982