Analysis of Small and Medium-Scale Cosmic Microwave Background   Experiments
  Anisotropies in the temperature of the cosmic microwave background have been detected on a range of scales by several different experiments. These anisotropies reflect the primordial spectrum of metric perturbations in the early universe. In principle, the largest barrier to a clean interpretation of the experimental results is contamination by foreground sources. We address this issue by projecting out likely sources of foreground contamination {}from seven separate small-angle and medium-angle experiments. We then calculate likelihood functions for models with adiabatic perturbations, first for the amplitude of the spectrum while constraining the spectral index to be $n=1$, and then jointly for the amplitude and spectrum of the fluctuations. All of the experiments are so far consistent with the simplest inflationary models; for $n=1$ the experiments' combined best-fit quadrupole amplitude is $Q_{\rm rms-ps}= 18^{+3}_{-1} \,\,\mu K$, in excellent agreement with the COBE two-year data. In ($Q_{\rm rms-ps}$, n) space, the allowed region incorporating intermediate and small-scale experiments is substantially more constrained than {}from COBE alone. We briefly discuss the expected improvement in the data in the near future and corresponding constraints on cosmological models. 
Scott Dodelson (Fermilab) and Arthur Kosowsky (University of Chicago   and CFA)