Cosmology with clusters of galaxies

In this Chapter I review the role that galaxy clusters play as tools to constrain cosmological parameters. I will concentrate mostly on the application of the mass function of galaxy clusters, while other methods, such as that based on the baryon fraction, are covered by other Chapters of the book. Since most of the cosmological applications of galaxy clusters rely on precise measurements of their masses, a substantial part of my Lectures concentrates on the different methods that have been applied so far to weight galaxy clusters. I provide in Section 2 a short introduction to the basics of cosmic structure formation. In Section 3 I describe the Press--Schechter (PS) formalism to derive the cosmological mass function, then discussing extensions of the PS approach and the most recent calibrations from N--body simulations. In Section 4 I review the methods to build samples of galaxy clusters at different wavelengths. Section 5 is devoted to the discussion of different methods to derive cluster masses. In Section 6 I describe the cosmological constraints, which have been obtained so far by tracing the cluster mass function with a variety of methods. Finally, I describe in Section 7 the future perspectives for cosmology with galaxy clusters and the challenges for clusters to keep playing an important role in the era of precision cosmology.Comment: 49 pages, 19 figures, Lectures for 2005 Guillermo Haro Summer School on Clusters, to appear in "Lecture notes in Physics" (Springer

Practical considerations for implementing an evidence-based policing approach in police operations: a case study

Through the lens of a real operation carried out at Greater Manchester Police to protect the business community from burglaries over the Christmas and New Year period in 2017/2018, this paper highlights the practical considerations in implementing an evidence-based approach in policing operations where there is a perceived immediate threat, risk and harm. Operation Guard was a force-wide operation that ran for four months (1st December 2017–30th March 2018 inclusive) across seven districts and eleven wards in Greater Manchester (UK), with the primary mandate of reducing Greater Manchester Police’s (GMP) commercial burglary crime volume. With the operation carrying a second aim of tactical delivery through an evidence-based policing methodology, representing the first of its kind at this scale at GMP, this paper highlights key practical considerations and learning opportunities for future tactical deployment for both police strategic and tactical leaders, as well as policing academics

Convergent cultural evolution and multilevel selection: Reply to comments on Janet Landa’s ‘The bioeconomics of homogenous middleman groups as adaptive units: Theory and empirical evidence viewed from a group selection framework’

Cultural diversity, Group selection, Proximate and ultimate causation, Fitness differences, The Law Merchant, K12, P51, Q57, Z1, Z12,