A Mysterious Duality

We establish a correspondence between toroidal compactifications of M-theory and del Pezzo surfaces. M-theory on T^k corresponds to P^2 blown up at k generic points; Type IIB corresponds to P^1\times P^1. The moduli of compactifications of M-theory on rectangular tori are mapped to Kahler moduli of del Pezzo surfaces.The U-duality group of M-theory corresponds to a group of classical symmetries of the del Pezzo represented by global diffeomorphisms. The half-BPS brane charges of M-theory correspond to spheres in the del Pezzo, and their tension to the exponentiated volume of the corresponding spheres. The electric/magnetic pairing of branes is determined by the condition that the union of the corresponding spheres represent the anticanonical class of the del Pezzo. The condition that a pair of half-BPS states form a bound state is mapped to a condition on the intersection of the corresponding spheres. We present some speculations about the meaning of this duality.Comment: 30 pages; A reference added; comments on quadratic transformation adde

Mysterious Bargaining

Economists do not understand how bargains are struck. A bargain is the sharing of a pie between two or more people who are collectively entitled to the pie but cannot appropriate it until they agree how large each person's slice is to be. We know that people do strike bargains and that civilized life could not proceed otherwise. We do not know how the required agreement is reached. Theorists have solved the bargaining problem, but only by the imposition of strong, artificial and unrealistic constraints. Trusting that the existence of some complex solution has been demonstrated, applied economists are content to postulate a simple one: that bargainers split the difference in actual disputes. This paper begins with examples of imposed bargaining solutions in politics and corporation finance. There follows a critical examination of the principal bargaining theories - based on notions of fairness or of imposed bargaining procedures - with emphasis on the fragility of their assumptions and on their susceptibility to threats and blackmail. The paper closes with a brief discussion of connections among theories of bargaining, rent-seeking and conflict.Bargaining, Fairness

That mysterious FOMC

Remarks before a meeting of The Economic Club of Memphis, Memphis - Dec. 3, 1998Federal Open Market Committee

FASB: Making Financial Statements Mysterious

Since the passage of the Sarbanes-Oxley Act in 2002, the Financial Accounting Standards Board has passed rules that it promises will make corporate accounting more transparent. In fact, its revised Generally Accepted Accounting Principles have made it difficult for investors -- or even CEOs -- to understand a company's financial report. The first step in the wrong direction came when FASB mandated that companies list "intangibles" such as "goodwill" as corporate assets, artificially inflating balance sheets. After that, FASB meddled with the revenue recognition rules, in some cases not allowing companies to report revenue from cash payments received from a customer for a delivered product. Finally, and worst by far, FASB mandated punitive and nonsensical rules for so-called expensing of stock options. These accounting burdens, combined with the onerous yet ineffective mandates of the Sarbanes-Oxley Act, are starting to take a real toll on American businesses and markets. In 2007, only $8.5 billion or 7.7 percent of the total$109 billion in issuances of Initial Public Offerings were launched on U.S. stock exchanges, down from 60.8 percent a decade ago

Problems with the "Problems" with psychophysical causation

In this essay, I defend a mind-body dualism, according to which human minds are immaterial substances that exercise non-redundant causal powers over bodies, against the notorious problem of psychophysical causation. I explicate and reply to three formulations of the problem: (i) the claim that, on dualism, psychophysical causation is inconsistent with physical causal closure, (ii) the claim that psychophysical causation on the dualist view is intolerably mysterious, and (iii) Jaegwon Kim’s claim that dualism fails to account for causal pairings. Ultimately, I conclude that these objections fail and that dualist interactionism is no more problematic or mysterious than physical causation

The "Mysterious" Origin of Brown Dwarfs

Hundreds of brown dwarfs (BDs) have been discovered in the last few years in stellar clusters and among field stars. BDs are almost as numerous as hydrogen burning stars and so a theory of star formation should also explain their origin. The ``mystery'' of the origin of BDs is that their mass is two orders of magnitude smaller than the average Jeans' mass in star--forming clouds, and yet they are so common. In this work we investigate the possibility that gravitationally unstable protostellar cores of BD mass are formed directly by the process of turbulent fragmentation. Supersonic turbulence in molecular clouds generates a complex density field with a very large density contrast. As a result, a fraction of BD mass cores formed by the turbulent flow are dense enough to be gravitationally unstable. We find that with density, temperature and rms Mach number typical of cluster--forming regions, turbulent fragmentation can account for the observed BD abundance.Comment: 11 pages, 3 figures, ApJ submitted Error in equation 1 has been corrected. Improved figure