Impact of prior assumptions on Bayesian estimates of inflation parameters and the expected gravitational waves signal from inflation

摘要: There has been much recent discussion, and some confusion, regarding the use of existing observational data to estimate likelihood that next-generation cosmic microwave background (CMB) polarization experiments might detect a nonzero tensor signal, possibly associated with inflation. We examine this issue in detail here two different ways: (1) first we explore effect choice parameter priors on estimation tensor-to-scalar ratio r other parameters describing inflation, (2) Bayesian complexity order determine how effectively can constrain inflationary parameters. demonstrate are not strong enough render full estimates parametrization- prior-independent way predicted signal is particularly sensitive priors. For parametrizations where comparable number free find flat prior scale inflation (which be distinguished from ratio) leads us infer larger, fact slightly contribution at 68% confidence level. However, no detection claimed. Our results all statistically relevant current time ismore » (slightly enhanced) upper bound r, stress remain consistent r=0.« less