Friday, April 29, 2011

Can Compressive Sensing Help Us Understand the Mass of the Universe.?

The week-end is approaching, it's time for thought provoking ideas. As I was watching the following movie from PhD comic it reminded me of the issue of gravitational lensing and how it fits with compressive sensing. If you want to do something in that direction, you may want to compete in the Star Challenge of the GIANT10 challenge (by the way I am trying to put all competitions and challenges in one place). From the movies, it is said that dark matter occupies 20% of the mass in the universe and normal matter fits only 5% while the remaining is unknown. Since the only way to visualize dark matter is through its lensing effect on light shone by normal matter and since what we see of matter is through these random assemblies of dark matter, how can general principles of compressive sensing help us understand the general distribution of mass in the universe ? The idea is that dark matter acts as a measurement matrix and we only get to see measurements. This is a typical blind deconvolution problem except if you are making inferences on the solution which at 5% mass looks to me like a small (sparse) quantity.

One more thing, today the last flight of Endeavor (STS-134) will put the Alpha Magnetic Spectrometer (AMS) on the truss of the International Space Station. The AMS will the first device outside earth atmosphere dedicated to detect dark matter. This is bittersweet to me personally since for a while we tried to get projects running on the truss of the ISS next to the AMS on the now defunct Express Pallets. Oh well.

Dark Matters from PHD Comics on Vimeo.

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