Weighing the Universe

Weighing the Universe.

Ideal scales for weighing the Universe

We investigate the performance of a large class of cosmic microwave background experiments with respect to their ability to measure various cosmological parameters. We pay special attention to the measurement of the total cosmological density, Ω. We consider interferometer experiments, all-sky single-dish experiments, and also single-dish experiments with a deep-patch technique. Power spectrum ...

Weighing the universe with the cosmic microwave background.

Variations in V, the total density of the Universe, leave an imprint on the power spectrum of temperature fluctuations in the cosmic microwave background (CMB). We evaluate the precision with which V can be determined by a CMB map as a function of sky coverage, pixel noise, and beam size. Assuming only that the primordial density perturbations were adiabatic and with no prior information on the...

Weighing the Universe with Photometric Redshift Surveys and the Impact on Dark Energy Forecasts

With a wariness of Occam’s razor awakened by the discovery of cosmic acceleration, we abandon the usual assumption of zero mean curvature and ask how well it can be determined by planned surveys. We also explore the impact of uncertain mean curvature on forecasts for the performance of planned dark energy probes. We find that weak lensing and photometric baryon acoustic oscillation data, in com...

Weighing the Scales:

Political science provides two very different takes on how the information revolution affects the relationship between governments and global civil society. The more popular and prominent argument is that the Internet dramatically lowers the costs of networked communication; therefore, civil society groups are better able to mobilize action to influence governments. Countless numbers of article...