Sep 28 @ 3:15 pm – 4:15 pm
Spatial Curvature, Dark Energy Dynamics, Neither, or Both?
Bharat Ratra, Kansas State University
Experiments and observations over the two last decades have persuaded cosmologists that (as yet undetected) dark energy is by far the main component of the energy budget of the current universe. I review a few simple dark energy models and compare their predictions to observational data, to derive dark energy model-parameter constraints and to test consistency of different data sets. I conclude with a list of open cosmological questions.
Nov 15 @ 3:15 pm – 4:15 pm
Using every photon to learn about the physics of solar plasmas
Phil Judge, High Altitude Observatory, Boulder CO.
The Sun has traditionally been the Rosetta Stone that can overcome the gap in regimes between laboratory and astronomical plasmas. Theories applicable in the laboratory may not readily apply to solar plasmas, and vice-versa. Yet we still face challenges in understanding how the observable plasmas are produced, and why the magnetic field threading and energizing them must globally reverse every 11 years. I will give a general overview of currently pressing problems in solar physics, followed by two specific examples: one concerning the physics of flares through infrared spectroscopy and polarimetry, the other concerning how we might wring every last ounce of information from the emitted photons. Along the way I will introduce the NMSU-operated Dunn Solar Telescope, the new DKIST, Parker Solar Probe and Solar Orbiter, and suggest how we might take advantage of these new facilities to make lasting progress.
Subscribe to filtered calendar