Date: |
August 21, 2008, 13:30 - 15:00 |
Place: |
Room 633, 6th floor, Research Centers Building, Kashiwa Campus of the University of Tokyo |
Speaker: |
David M. Goldberg (Drexel University) |
Title: |
Where is the Information in Cluster Lenses?
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Abstract: |
Clusters of galaxies are the largest collapsed structures in the
universe. Accurate measurement of their masses provide constraints
on the total mass in the universe and accurate measurement of their
shapes and substructure constrain the growth of structure in the CDM
paradigm. Clusters are also unique amongst gravitational lenses in
that they produce both weak arclets, as well as multiply imaged
dramatic arcs. In the last few years, there have been a number of
new techniques synthesizing various components of cluster lensing
signals in an attempt to get the most accurate reconstructions
possible. In this talk, I will discuss 1) Some of the major
observational results over the last few years, including the "direct
identification" of dark matter clumps in 1E 0657-56, the bullet
cluster, 2) Some of the methods that researchers have used to try to
incorporate new signals in lensing analysis (e.g. "Flexion" and
"HOLICs") as well as "Strong+Weak" methods to try to synthesize
different lensing signals, including a new technique called "Particle-
Based Lensing" by my own group, and 3) The title of this talk. I
will describe our current work to identify the Fisher Information in
various parts of the cluster. I will also discuss how an infor
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