A Measurement of the Cosmic Microwave Background Damping Tail from the
  2500-square-degree SPT-SZ survey
  We present a measurement of the cosmic microwave background (CMB) temperature
power spectrum using data from the recently completed South Pole Telescope
Sunyaev-Zel'dovich (SPT-SZ) survey. This measurement is made from observations
of 2540 deg$^2$ of sky with arcminute resolution at $150\,$GHz, and improves
upon previous measurements using the SPT by tripling the sky area. We report
CMB temperature anisotropy power over the multipole range $650<\ell<3000$. We
fit the SPT bandpowers, combined with the seven-year Wilkinson Microwave
Anisotropy Probe (WMAP7) data, with a six-parameter LCDM cosmological model and
find that the two datasets are consistent and well fit by the model. Adding SPT
measurements significantly improves LCDM parameter constraints; in particular,
the constraint on $\theta_s$ tightens by a factor of 2.7. The impact of
gravitational lensing is detected at $8.1\, \sigma$, the most significant
detection to date. This sensitivity of the SPT+WMAP7 data to lensing by
large-scale structure at low redshifts allows us to constrain the mean
curvature of the observable universe with CMB data alone to be
$\Omega_k=-0.003^{+0.014}_{-0.018}$. Using the SPT+WMAP7 data, we measure the
spectral index of scalar fluctuations to be $n_s=0.9623 \pm 0.0097$ in the LCDM
model, a $3.9\,\sigma$ preference for a scale-dependent spectrum with $n_s<1$.
The SPT measurement of the CMB damping tail helps break the degeneracy that
exists between the tensor-to-scalar ratio $r$ and $n_s$ in large-scale CMB
measurements, leading to an upper limit of $r<0.18$ (95%,C.L.) in the LCDM+$r$
model. Adding low-redshift measurements of the Hubble constant ($H_0$) and the
baryon acoustic oscillation (BAO) feature to the SPT+WMAP7 data leads to
further improvements. The combination of SPT+WMAP7+$H_0$+BAO constrains
$n_s=0.9538 \pm 0.0081$ in the LCDM model, a $5.7\,\sigma$ detection of $n_s <
1$, ... [abridged]
