Weak gravitational lensing is considered to be one of the most powerful tools to study the mass and the mass distribution of galaxy clusters. However, weak lensing mass reconstructions are plagued by the so-called mass-sheet degeneracy – the surface mass density κ of the cluster can be determined only up to a degeneracy transformation κ → κ′ = λκ+(1−λ), where λ is an arbitrary constant. This tr...

Weak gravitational lensing is considered to be one of the most powerful tools to study the mass and the mass distribution of galaxy clusters. However, weak lensing mass reconstructions are plagued by the so-called mass-sheet degeneracy – the surface mass density κ of the cluster can be determined only up to a degeneracy transformation κ → κ′ = λκ+ (1− λ), where λ is an arbitrary constant. This ...

In order to understand organizational memory, it is important to understand how things become adopted as memory resources in organizations. In this paper, we describe the genesis and use of an artifact that became a memory resource for a wide range of activities. We discuss how the creation and use of the rush cheat sheet (RCS) and its associated representations at Dallas Ft. Worth TRACON broug...