Two of the greatest mysteries in cosmology — and indeed all of modern physics — involve the exponential growth of space: the inflationary period of the early Universe, and the present-day Dark Energy-driven expansion. Recent technological advances are fuelling the exploration of these twin phenomena, allowing precise measurements spanning broad swaths of the observable Universe.

The 10m South Pole Telescope (SPT) has surveyed a 2500 deg^2 patch of the southern microwave sky, and has already yielded considerable insights into these periods of expansion: measurements of the angular power spectrum of the CMB are beginning to constrain models of inflation, while growth-of-structure measurements, probed through the evolution of the galaxy cluster population, now constrain the behaviour of Dark Energy.

I’ll discuss these results, as well as prospects for a pair of new experiments: a polarization-sensitive upgrade to SPT, which will precisely measure the polarized properties of the CMB, potentially detecting the “smoking gun” of inflation, the imprint of primordial gravity waves; and the Canadian Hydrogen Intensity Mapping Experiment (CHIME), which is poised to take a global lead on mapping the large scale structure of the Universe, thereby precisely measuring the Dark Energy-driven expansion of space.