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1138 1492515864

A new method for inferring the 3D matter distribution from cosmic shear data

  • Datum: 21.04.2017
  • Uhrzeit: 14:00 - 15:00
  • Vortragender: Vanessa Boehm (MPA)
  • Ort: MPA
  • Raum: Large Seminar Room E 0.11
  • Gastgeber: MPA
Tomographic lensing measurements offer a powerful probe for time-resolving the clustering of matter over a wide range of scales. Since full, high resolution reconstructions of the matter field from cosmic shear measurements are ill-constrained, they commonly rely on spatial averages and prior assumptions about the noise and signal statistics. I will present a new, Bayesian method to perform such a reconstruction. Our likelihood can take into account individual galaxy contributions, thereby also accounting for their individual redshift uncertainties. As a prior, we use a lognormal distribution which significantly better captures the non-linear properties of the underlying matter field than the commonly used Gaussian prior. After reviewing the algorithm itself, I will show results from testing it on mock data generated from fully non-linear density distributions. These tests reveal the superiority of the lognormal prior over existing methods in regions with high signal-to-noise.

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