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Riegl praises Rembrandt for the discipline with which he maintains the pattern of subordination that foregrounds the two officers and isolates them from the remainder of the company. Several commentators have noted resemblances between Cocq and the figure of Cornelis Claesz. Presumably the sitters collaborate with the painter in setting the visual scene, and presumably the painting reflects their efforts to control the final product, including, no doubt, requests for alteration of details that do not suit sitters. But although the painting itself may represent sitters' efforts to control it, there are indications that it challenges such efforts. Rembrandt's competition with the sitters brings out theirs with each other.

One of the most surprising developments in the SUSY theories was the realization that certain supergravity theories in higher dimensions are dual to 4D CFTs. In particular, several supergravity theories on a 5D anti-de Sitter (AdS) space with an additional 5D compact space have been studied in detail and the corresponding CFT identified. This chapter presents an overview of the AdS/CFT correspondence. Topics covered include D-brane constructions of gauge theories, the supergravity approximation, waves of AdS₅, nonperturbative static Coulomb potential, and SUSY breaking.

The anomalies that the author has described in this section offer a good reason to cling to the helium-filled balloon of allegory that carries viewers safely above the ground plane of unruly detail. At least two hypotheses may be advanced against the tendency toward allegorical evasion. One is weaker because it is purely a general and aesthetic speculation, the other stronger because it engages a possible historical motive. The pretense of ineffectual guardsmanship must be marked as merely a pretense, a theatrical performance. The sitters thus give themselves to be seen making a divided commitment to the demands of portraiture and to those of narrative action.

Modern theoretical cosmology is essentially based on Einstein's theory of general relativity, with which this chapter starts. His original relativistic model of 1917 was closed and static, and made use of the so-called cosmological constant. The static nature of the universe, whether in Einstein's model or the one proposed by Willem de Sitter, had a paradigmatic status in early relativistic cosmology. However, the paradigm broke down in the early 1930s when Hubble's observations were combined with the theoretical works of Friedmann and Georges Lemaître. From that time onward, the expanding universe became part of mainstream cosmology. However, in the 1930s there was not yet a settled framework of cosmology, a science where unorthodox theories flourished and where mathematical reasoning dominated over physical considerations.

A funny thing happens behind the backs of Captain Frans Banning Cocq and Lieutenant Wilhelm van Ruytenburgh when they are on the point of leading their company to an unspecified site of assembly or action. We can see the barrel angle up from the Captain's shoulder to the Lieutenant's hat brim and we can make out the puff of fiery smoke it discharges perilously close to the ostrich plumes, which seem flattened back by the blast. That the officers soldier on as if they hadn't heard or felt the shot testifies to their remarkable discipline, or insensitivity, or something else. Sitters are the patrons' representatives, by which the author means that they get portrayed as if their performances are self-willed rather than externally imposed. Sitters appear to have chosen the poses they hold, and in that sense they are depicted as independent agents.

What Jesper Svenbro says of the amphora applies to the painted portrait in that both outlast their creators. But portraiture involves not only the painter and the painting; it also involves the patron and the sitter. The redundancy or recursiveness of this statement is its most important property because it reminds us that the act of portrayal in which painter and sitter collaborate is an example of what Victor Stoichita calls a “metapictorial act,” an act of representing representation. Portraits are often defined, understood, and written about as pictures of somebody. David R. Smith views portraits as personae, “masks of identity and celebrations of social ritual.” Unlike candid photographs, they “reflect moments of selfconscious encounter with other human beings.” The act of posing may itself be a socially charged performance, an indicator of success.

The author calls the figures in narrative genres characters in order to distinguish them from the sitters in portrait genres. The sitter's situation differs from that of the characters in such narrative modes as history and Genre painting. David Smith argues that the portrait and Genre genres are easy to distinguish because “people in portraits usually look out at us, as they generally do not in genre painting.” Many sitters, and some characters, do make contact, but the meaning of this contact, and the invitation to the observer, are different for each generic code. Steen's “metapictorial” project, then, is to sharpen the viewer's awareness of the predicament of models holding poses while pretending to interact among themselves.

The safest definition of a group portrait is that it is a picture in which sitters pretending to pose together actually posed separately. All portraits pretend to be copies of those who sat for them, but the group portrait as a genre foregrounds the element of pretense. The occasion of group portraiture as an institutional practice is intended to promote and commemorate the kind of solidarity that defends against the threat of disaggregation. But the form of group portraiture as a representational practice is infiltrated by that threat, and reactivates it. The author concluded this chapter with a methodological caveat. The drama and the psychology of posing may not loom very large in the economy of human life. Posographical interpretations of sitters are at once more limited and more expressly hypothetical in their claims than those we associate with general psychology.

Riegl made changing sitter/observer relations the conceptual center of his master narrative, which was shaped by the conviction that the genre's defining characteristic was the subjective factor of attention or attentiveness (Aufmerksamkeit), the third in the triad of attitudes that constitute his “psychological typology.” Aufmerksamkeit is the attentiveness of the sitters to each other and to the viewer, and the attentiveness of the viewer to the sitters as a group and as individuals. Posing as if not posing may well produce the anecdotal Genre effect even to the extent of suggesting action that involves participant observers. Riegl's account of group portraiture elides a prior and more basic pretense. Riegl imagines observer space peopled by virtual viewers invisible to us but not to the sitters.

Margaret Carroll resists the traditional view that unity was a positive value and that Rembrandt achieved it by “conveying the present-day activities of Amsterdam's militia companies and at the same time recalling their historical role as armed and trained troops in service to the city and the republic.” Inattention and self-absorption are suggested by other means. There is lack of coordination not only within the figure—between the slackness of the lower, gun-bearing hand and the finicky finger-work of the upper hand—but also between this sitter and the others. The obvious problem to avoid is an interpretation that reduces the sitters to unwitting targets of Rembrandt's satire.

Starting with the assumptions of homogeneity and isotropy, the cosmological solutions of the Einstein field equations—the Friedmann-Lemaitre-Robertson-Walker metrics—are derived. After a discussion of constant curvature metrics and the topology of the Universe, the chapter moves on to discuss observational implications: expansion of the Universe, cosmological red shift, primordial nucleosynthesis, the cosmic microwave background, and primordial perturbations. The chapter includes a brief discussion of de Sitter and anti-de Sitter space and an introduction to inflation.

We obtain the interior Schwarzschild solution; the stellar structure equations (Tolman-Oppenheimer-Volkoff); the Reissner-Nordstrom metric (charged black hole) and the de Sitter-Schwarzschild metric. These both illustrate how the field equation is tackled in non-vacuum cases, and bring out some of the physics of stars, electromagnetic fields and the cosmological constant.

The chapter deals with the large-scale dynamics of the universe. First the Friedmann equations are obtained from the Einstein field equation, and they are interpreted with the aid of a Newtonian comparison. Then the application to the universe modelled as a collection of ideal fluids is described. Density parameters and the equation of the state are defined, and the main features of the evolution of matter, radiation and the vacuum are obtained. Analytic solutuions in various simple cases are found. Dark matter and dark energy are defined through their observational evidence. The particle horizon is defined and discussed. The density and temperature at last scattering are calculated by a model involving Thomson scattering, expansion, and the Saha equation.

In previous chapters we presented the key notions associated with stationary black-hole spacetimes, as well as the minimal set of metrics needed to illustrate the basic features of the world of black holes. In this chapter we present some further black holes, selected because of their physical and mathematical interest. We start, in Section 5.1, with the Kerr–de Sitter/anti-de Sitter metrics, the cosmological counterparts of the Kerr metrics. Section 5.2 contains a description of the Kerr–Newman–de Sitter/anti-de Sitter metrics, which are the charged relatives of the metrics presented in Section 5.1. In Section 5.3 we analyse in detail the global structure of the Emparan–Reall ‘black rings’: these are five-dimensional black-hole spacetimes with R × S₁ × S₂-horizon topology. The Rasheed metrics of Section 5.4 provide an example of black holes arising in Kaluza–Klein theories. The Birmingham family of metrics, presented in Section 5.5, forms the most general class known of explicit static vacuum metrics with cosmological constant in all dimensions, with a wide range of horizon topologies.

This chapter discusses the first wave of the exploration of exact solutions to Einstein's gravitational field equations. When Einstein published the final form of the field equations in 1915, only an approximate solution was known. Given the complicated nonlinear character of the field equations, he did not expect that exact solutions could easily be found. He was all the more surprised when the astronomer Karl Schwarzschild presented him with just such an exact solution. Thus, this chapter presents a series of these solutions, beginning with the work of Karl Schwarzschild, Johannes Droste, Willem de Sitter, Alexander Friedmann, Hans Reissner, Gunnar Nordström, and finally, Georges Lemaître.

This chapter highlights the background for the emergence of relativistic cosmology. A specific interpretational issue, which is treated in this context, is the role of Ernst Mach's principle and the first exploration of the cosmological consequences of general relativity. Here Einstein's main interlocutor was the Dutch astronomer Willem de Sitter. But during the years 1916 to 1918, Einstein also exchanged letters with the mathematicians Hermann Weyl and Felix Klein. This correspondence has been referred to as the Einstein–de Sitter–Weyl–Klein debate. This debate not only focused on specific cosmological models but also helped to clarify the meaning of such fundamental issues as coordinates and energy-momentum conservation in the theory. This chapter also discusses the implications of Hubble's discovery.

This chapter addresses the hostility between players and playgoers that playing repeatedly rehearses, in plays like Midsummer Night’s Dream, Beaumont’s Knight of the Burning Pestle, and Jonson’s The New Inn. Sometimes the hostility was actual, as when stage-sitters disrupted a performance; more often it was a way of understanding the sometimes fraught negotiations within the playhouse. Playing represented itself as a recurring contest in which the co-presence of players and playgoers transforms action and meaning. Playing shared personnel, spaces, and audiences with fencing and bearbaiting, and so was understood in relation to these combat sports. In actual practice playing was closer to fencing, and many plays draw heavily on stage combat whether with swords or words. But to represent its own practices playing turned more often to bearbaiting. In plays, images of bearbaiting single out a lone heroic figure beset by lesser ones. The bearbaiting playing thus imagined seems not to have been like bearbaiting as it was historically practiced. Playing represented its ideal conclusion to violence as a non plus, a decisive blow that brooked no answer and thus allowed something new beyond violence to emerge from it.