Physical constraints on the coefficients of Fourier expansions in cylindrical coordinates

It is demonstrated that (i) the postulate of infinite differentiability in Cartesian coordinates and (ii) the physical assumption of regularity on the axis of a cylindrical coordinate system provide significant simplifying constraints on the coefficients of Fourier expansions in cylindrical coordinates. These constraints are independent of any governing equations. The simplification can provide considerable practical benefit for the analysis (especially numerical) of actual physical problems. Of equal importance, these constraints demonstrate that if A is any arbitrary physical vector, then the only finite Fourier terms of A_r and A_θ are those with m=1 symmetry. In the Appendix, it is further shown that postulate (i) may be inferred from a more primitive assumption, namely, the arbitrariness of the location of the cylindrical axis of the coordinate system

Stability Issues for w < -1 Dark Energy

Precision cosmological data hint that a dark energy with equation of state $w = P/\rho < -1$ and hence dubious stability is viable. Here we discuss for any $w$ nucleation from $\Lambda > 0$ to $\Lambda = 0$ in a first-order phase transition. The critical radius is argued to be at least of galactic size and the corresponding nucleation rate is glacial, thus underwriting the dark energy's stability and rendering remote any microscopic effect.Comment: 9 pages LaTeX. Significantly rewritten (including abstract

Deposit insurance, bank incentives, and the design of regulatory policy

This paper was presented at the conference "Financial services at the crossroads: capital regulation in the twenty-first century" as part of session 6, "The role of capital regulation in bank supervision." The conference, held at the Federal Reserve Bank of New York on February 26-27, 1998, was designed to encourage a consensus between the public and private sectors on an agenda for capital regulation in the new century.Deposit insurance ; Bank investments ; Bank supervision ; Bank capital

Tort Reform and Accidental Deaths

Theory suggests that tort reform could have either of two impacts on accidents. First, reforms could increase accidents as tortfeasors internalize less of the costs of externalities, and thus, have less incentive to reduce the risk of accidents. Second, tort reforms could decrease accidents as lower expected liability costs result in lower prices, enabling consumers to buy more risk-reducing products such as medicines, safety equipment, and medical services. We test which effect dominates by examining the effect of tort reforms on non-motor vehicle accidental death rates, using panel data techniques. We find that caps on noneconomic damages, caps on punitive damages, a higher evidence standard for punitive damages, product liability reform, and prejudgment interest reform lead to fewer accidental deaths, while reforms to the collateral source rule lead to increased deaths. Overall, the tort reforms in the states between 1981-2000 have led to an estimated 14,222 fewer accidental deaths.

Current-induced torques due to compensated antiferromagnets

We analyse the influence of current induced torques on the magnetization configuration of a ferromagnet in a circuit containing a compensated antiferromagnet. We argue that these torques are generically non-zero and support this conclusion with a microscopic NEGF calculation for a circuit containing antiferromagnetic NiMn and ferromagnetic Co layers. Because of symmetry dictated differences in the form of the current-induced torque, the phase diagram which expresses the dependence of ferromagnet configuration on current and external magnetic field differs qualitatively from its ferromagnet-only counterpart.Comment: 4 pages, 5 figure