New Developments in Treacherous Points of Light-Front Dynamics

Light-front dynamics(LFD) plays an important role in hadron phenomenology. Last few years, however, it has been emphasized that treacherous points such as zero-mode contributions should be taken into account for successful LFD applications to hadron phenomenology. We discuss examples of treacherous points and present new progresses made last few years to handle them correctly.Comment: 5 pages, espcrc1.sty. proceedings of FB XVIII (August 2006, Brazil), to be published in Nucl. Phys.

A classification of Lagrangian planes in holomorphic symplectic varieties

Classically, an indecomposable class $R$ in the cone of effective curves on a K3 surface $X$ is representable by a smooth rational curve if and only if $R^2=-2$. We prove a higher-dimensional generalization conjectured by Hassett and Tschinkel: for a holomorphic symplectic variety $M$ deformation equivalent to a Hilbert scheme of $n$ points on a K3 surface, an extremal curve class $R\in H_2(M,\mathbb{Z})$ in the Mori cone is the line in a Lagrangian $n$-plane $\mathbb{P}^n\subset M$ if and only if certain intersection-theoretic criteria are met. In particular, any such class satisfies $(R,R)=-\frac{n+3}{2}$ and the primitive such classes are all contained in a single monodromy orbit.Comment: 18 pages, comments welcome. v3: classification extended to all curve classes; some examples added. v4: to appear in J. Inst. Math. Jussie

The End of Epicurean Infinity: Critical Reflections on the Epicurean Infinite Universe

In contrast to other ancient philosophers, Epicurus and his followers famously maintained the infinity of matter, and consequently of worlds. This was inferred from the infinity of space, because they believed that a limited amount of matter would inevitably be scattered through infinite space, and hence be unable to meet and form stable compounds. By contrast, the Stoics claimed that there was only a finite amount of matter in infinite space, which stayed together because of a general centripetal tendency. The Roman Epicurean poet Lucretius tried to defend the Epicurean conception of infinity against this Stoic alternative view, but not very convincingly. One might suspect, therefore, that the Epicureans’ adherence to the infinity of matter was not so much dictated by physical arguments as it was motivated by other, mostly theological and ethical, concerns. More specifically, the infinity of atoms and worlds was used as a premise in several arguments against divine intervention in the universe. The infinity of worlds was claimed to rule out divine intervention directly, while the infinity of atoms lent plausibility to the chance formation of worlds. Moreover, the infinity of atoms and worlds was used to ensure the truth of multiple explanations, which was presented by Epicurus as the only way to ward off divine intervention in the realm of celestial phenomena. However, it will be argued that in all of these arguments the infinity of matter is either unnecessary or insufficient for reaching the desired conclusion

Revealing treacherous points for successful light-front phenomenological applications

Light-front dynamics(LFD) plays an important role in hadron phenomenology as evidenced from recent development of generalized parton distributions and other quantities involving hadrons. For successful LFD applications to hadron phenomenology, however, treacherous points such as zero-mode contributions should be taken into account. For a concrete example of zero-mode contribution, we present Standard Model analysis of vector anomaly in the CP-even form factors of W^{\pm} gauge bosons. Main distinguished features of LFD is discussed in comparison with other Hamiltonian dynamics. We also present a power counting method to correctly pin down which hadron form factors receive the zero-mode contribution and which ones do not. Indications from our analysis to hadron phenomenology are discussed.Comment: 6 pages; requires espcrc2.sty; to appear in the proceedings of Workshop on Light-Cone QCD and Nonperturbative Hadron Physics 2005 (LC 2005), Cairns, Queensland, Australia, 7-15 Jul 200

About the Cover Art

I made this drawing in 2016 as cover for our prison newsletter. I have been in prison for many years. I wanted this drawing to be a metaphor of what I think is the usual relationship between prison staff and prisoners. The snake represents the prevailing justice system and how it works in jail. The snake disguises itself in the wall, always ready, sneaking in and out to look upon the prisoner and prey on him, but never in the open. The system always wants us to be responsible but simultaneously creates a completely impossible environment in which to show that responsibility, driving prisoners to absurd situations if they attempt to follow the rules and powerless to defend themselves from the results. The snake is still there today, but fortunately I keep it in the wall, away from me as much as possible. --Loco (M.B.

Sunk costs and the dynamics of creative industries

This chapter examines the long-run evolution of modern entertainment industries such as the film and music industries. It investigates ways to conceptualise and quantify the subsequent waves of creative destruction, and investigates specifically how sunk costs affect the evolution of the industry through its interaction with variety, market integration, product differentiation and price discrimination, and how old entertainment formats almost never became extinct. It finds that within this framework, four economic tendencies shaped the entertainment industries evolution: first, endogenous sunk costs often led to a competitive escalation of production expenditures, which we call ‘quality races’, which increased industrial concentration. Second, the fact that marginal revenues largely equalled marginal profits led to extreme vertical integration through ownership or revenue-sharing contracts, as well as to an oversupply of variety and a dual market structure with high-concept blockbuster products and low-budget niche products. Third, entertainment’s public good characteristics led to substantial income inequality among creative inputs and business models optimising exclusion possibilities in the value chain. Finally, the project-based character of entertainment production implied large intra- and inter-industry agglomeration benefits and often led to geographical concentration. Dynamic product differentiation allowed various old formats to survive the waves of creative destruction, albeit in much smaller incarnations