Connecting In ation to Observations
نویسنده
چکیده
After a decade which has spawned an ever-enlarging zoo of innationary models (see 1] for a recent review), we are now entering an era where observational advances will be suuciently rapid as to impose signiicant constraints, with the possibility that innationary models may be excluded more quickly than new ones devised. The most important constraints on innationary models arise from the perturbation spectra which they produce, both density perturbations and gravitational waves. At this meeting much has been said about the gravitational waves, and rather less about the density perturbations. However, the present situation is that a variety of observations constrain the form of density perturbations whilst no positive detection has been made of gravitational waves, so at present one must concentrate on the former. It is well established that even if one allows the innationary potential V () for the innaton eld to be an arbitrary function, then barring pathologies the innationary prediction is accurately given via the slow-roll approximation and depends only on two parameters 2, 3], the so-called slow-roll parameters = m 2 P l evaluated when the scales of interest crossed outside the Hubble radius during innation. Primes are derivatives with respect to. The simplest reinterpretation of these parameters in terms of observables is as the spectral index n of the density perturbations and the contribution R of gravitational waves (relative to density perturbations) to large angle microwave background anisotropies
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