Why We Buy Books

Publishing is often characterized by instinctive decision-making with little attempt to apply a scientific methodology to an obvious question: why does one book sell and another not? The thesis of this paper is that, although there are aspects of a book’s publication history that one cannot predict in advance, one can know what these aspects are. A simple syllogism underlies the argument: if human behaviour can be understood through psychology and if book-buying is a form of behaviour, the motivations for book-buying can also be understood through psychology. This approach can be applied historically, through recourse to sales data, to trace the fossils of books published long ago and so discover the type and strength of the motivations that once drove people to buy them. History demonstrates that these motivations, once properly framed, can be understood to be influenced by context. Book-buying motivations also appear cyclically. This leads to a discussion of why it is that one book rather than another may satisfy a motivation and therefore sell better than another. Using the concept of prisms combining to reflect a motivational ‘light’, we see that books exist as constructs of a finite range of elements that cohere (or not) in a multiplicative way to enhance or diminish their effectiveness. Evidence is also given for what appears to be a universal ratio that dictates a natural entropy in the effectiveness of these prismatic elements.

Holographic superconductor from a noncommutative-inspired anti-de Sitter–Einstein–Born–Infeld black hole

Using a noncommutative-inspired anti-de Sitter–Einstein–Born–Infeld black hole with both noncommutative mass and charge distributions, we analyse a holographic superconductor in the context of the AdS/CFT correspondence. We show that the coupling of the Born–Infeld parameter and the noncommutative perturbations provides an enhancing mechanism for higher values of the expectation value of the condensate. Furthermore, we remark that noncommutativity counter-balances the nonlinearity of the electrodynamics to maintain the universal ratio of [Formula: see text].

Extreme submillimetre starburst galaxies

We have used two catalogues, a Herschel catalogue selected at 500 μm (HerMES) and an IRAS catalogue selected at 60 μm (RIFSCz), to contrast the sky at these two wavelengths. Both surveys demonstrate the existence of “extreme” starbursts, with star-formation rates (SFRs) > 5000 M⊙ yr−1. The maximum intrinsic star-formation rate appears to be ~30 000 M⊙ yr−1. The sources with apparent SFR estimates higher than this are in all cases either lensed systems, blazars, or erroneous photometric redshifts. At redshifts between three and five, the time-scale for the Herschel galaxies to make their current mass of stars at their present rate of star formation is ~108 yr, so these galaxies are making a significant fraction of their stars in the current star-formation episode. Using dust mass as a proxy for gas mass, the Herschel galaxies at redshift three to five have gas masses comparable to their mass in stars. Of the 38 extreme starbursts in our Herschel survey for which we have more complete spectral energy distribution (SED) information, 50% show evidence for QSO-like optical emission, or exhibit AGN dust tori in the mid-infrared SEDs. In all cases however the infrared luminosity is dominated by a starburst component. We derive a mean covering factor for AGN dust as a function of redshift and derive black hole masses and black hole accretion rates. There is a universal ratio of black-hole mass to stellar mass in these high redshift systems of ~10−3, driven by the strong period of star-formation and black-hole growth at z = 1−5.

Universal ratio of Coulomb interaction to geometric quantization in (In, Ga)As/GaAs quantum dots

We study the photoluminescence of self-assembled (In,Ga)As/GaAs quantum dot ensembles with varying confinement potential height. The low energy shift of the s -shell emission with increasing excitation power gives a measure of the Coulomb interaction in these structures as it results from carrier–carrier interactions between the optically injected exciton complexes. When dividing this shift by the dot level splitting, determined by the geometric confinement, we obtain a universal function of the number of involved excitons that is independent of the confinement potential height. This shows an identical scaling of Coulomb interaction and geometric quantization with varying confinement.

THE SHEAR VISCOSITY TO ENTROPY RATIO: A STATUS REPORT

This review highlights some of the lessons that the holographic gauge/gravity duality has taught us regarding the behavior of the shear viscosity to entropy density in strongly coupled field theories. The viscosity to entropy ratio has been shown to take on a very simple universal value in all gauge theories with an Einstein gravity dual. Here we describe the origin of this universal ratio, and focus on how it is modified by generic higher derivative corrections corresponding to curvature corrections on the gravity side of the duality. In particular, certain curvature corrections are known to push the viscosity to entropy ratio below its universal value. This disproves a longstanding conjecture that such a universal value represents a strict lower bound for any fluid in nature. We discuss the main developments that have led to insight into the violation of this bound, and consider whether the consistency of the theory is responsible for setting a fundamental lower bound on the viscosity to entropy ratio.

The Interannual Relationship between the Latitude of the Eddy-Driven Jet and the Edge of the Hadley Cell

A strong correlation between the latitudes of the eddy-driven jet and of the Hadley cell edge, on interannual time scales, is found to exist during austral summer, in both the NCEP–NCAR reanalysis and the models participating in the Coupled Model Intercomparison Project, phase 3 (CMIP3). In addition, a universal ratio close to 1:2 characterizes the robust connection between these two latitudes on a year-to-year basis: for a 2° shift of the eddy-driven jet, the edge of the Hadley cell shifts by 1°. This 1:2 interannual ratio remains the same in response to climate change, even though the values of the two latitudes increase. The corresponding trends are also highly correlated; in the CMIP3 scenario integrations, however, no universal ratio appears to exist connecting these long-term trends. In austral winter and in the Northern Hemisphere, no strong interannual correlations are found.