dark matter and over-fitting

Neal Weiner (NYU) gave an informal talk at lunch about the possibility that even if the dark matter is WIMPs, and even if it has a very high mass and low cross-section for annihilation (as it must for standard WIMP models), it can in principle create observable emission in the light sector if it has a low-energy excitation or energy splitting. He discussed this kind of model in the context of the excess of positron annihilation radiation observed near the Galactic Center.

Moustakas found that at high polynomial order, we may be over-fitting the small-scale astrometric distortions in his imaging data; going to lower order may improve the fits as well as simplify them. He also finds a very large number of moving objects in his images; we don't really know what moving object density to expect at the magnitudes and time baselines to which his data are sensitive.

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