The State of U.S. Corporate Governance: What's Right and What's Wrong?

The U.S. corporate governance system has recently been heavily criticized, largely as a result of failures at Enron, WorldCom, Tyco and some other prominent companies. Those failures and criticisms, in turn, have served as catalysts for legislative change (Sarbanes-Oxley Act of 2002) and regulatory change (new governance guidelines from the NYSE and NASDAQ). In this paper, we consider two questions. First, is it clear that the U.S. system has performed that poorly; is it really that bad? Second, will the changes lead to an improved U.S. corporate governance system? We first note that the broad evidence is not consistent with a failed U.S. system. The U.S. economy and stock market have performed well both on an absolute basis and relative to other countries over the past two decades. And the U.S. stock market has continued to outperform other broad indices since the scandals broke. Our interpretation of the evidence is that while parts of the U.S. corporate governance system failed under the exceptional strain of the 1990s, the overall system, which includes oversight by the public and the government, reacted quickly to address the problems. We then consider the effects that the legislative, regulatory, and market responses are likely to have in the near future. Our assessment is that they are likely to make a good system better, though there is a danger of overreacting to extreme events.

The State of Corporate Governance 2004

The U.S. corporate governance system has recently been heavily criticized, largely as a result of failures at Enron, WorldCom, Tyco and some other prominent companies. Those failures and criticisms, in turn, have served as catalysts for legislative change (Sarbanes-Oxley Act of 2002) and regulatory change (new corporate governance listing standards from the NYSE and NASDAQ). In this paper, we consider two questions. First, is it clear that the U.S. system has performed that poorly; is it really that bad? Second, will the changes lead to an improved U.S. corporate governance system. We first note that the broad evidence is not consistent with a failed U.S. system. The U.S. economy and stock market have performed well both on an absolute basis and relative to other countries over the past two decades. And the U.S. stock market continued to outperform other broad indices after the scandals broke. Our interpretation of the evidence is that while parts of the U.S. corporate governance system failed under the exceptional strain of the 1990s, the overall system, which includes oversight by the public and the government, reacted quickly to address the problems. We then consider the effects that the legislative, regulatory, and market responses are likely to have in the near future. Our assessment is that they are likely to make a good system better, though there is a danger of overreacting to extreme events.Technology and Industry, Regulatory Reform

Nonlinear evolution equations for degenerate transverse waves in anisotropic elastic solids

Transverse elastic waves behave differently in nonlinear isotropic and anisotropic media. Quadratically nonlinear coupling in the evolution equations for wave amplitudes is not possible in isotropic solids, but such a coupling may occur for certain directions in anisotropic materials. We identify the expression responsible for the coupling and we derive coupled canonical evolution equations for transverse wave amplitudes in the case of two-fold and three-fold symmetry acoustic axes. We illustrate our considerations by examples for a cubic crystal.Comment: 4 page

Towards a working density-functional theory for polymers: First-principles determination of the polyethylene crystal structure

Equilibrium polyethylene crystal structure, cohesive energy, and elastic constants are calculated by density-functional theory applied with a recently proposed density functional (vdW-DF) for general geometries [Phys. Rev. Lett. 92, 246401 (2004)] and with a pseudopotential-planewave scheme. The vdW-DF with its account for the long-ranged van der Waals interactions gives not only a stabilized crystal structure but also values of the calculated lattice parameters and elastic constants in quite good agreement with experimental data, giving promise for successful application to a wider range of polymers.Comment: 4 pages, 3 figure

Nonlinear propagation of light in Dirac matter

The nonlinear interaction between intense laser light and a quantum plasma is modeled by a collective Dirac equation coupled with the Maxwell equations. The model is used to study the nonlinear propagation of relativistically intense laser light in a quantum plasma including the electron spin-1/2 effect. The relativistic effects due to the high-intensity laser light lead, in general, to a downshift of the laser frequency, similar to a classical plasma where the relativistic mass increase leads to self-induced transparency of laser light and other associated effects. The electron spin-1/2 effects lead to a frequency up- or downshift of the electromagnetic (EM) wave, depending on the spin state of the plasma and the polarization of the EM wave. For laboratory solid density plasmas, the spin-1/2 effects on the propagation of light are small, but they may be significant in super-dense plasma in the core of white dwarf stars. We also discuss extensions of the model to include kinetic effects of a distribution of the electrons on the nonlinear propagation of EM waves in a quantum plasma.Comment: 9 pages, 2 figure

Generation of spin-wave dark solitons with phase engineering

We generate experimentally spin-wave envelope dark solitons from rectangular high-frequency dark input pulses with externally introduced phase shifts in yttrium-iron garnet magnetic fims. We observe the generation of both odd and even numbers of magnetic dark solitons when the external phase shift varies. The experimental results are in a good qualitative agreement with the theory of the dark-soliton generation in magnetic films developed earlier [Phys. Rev. Lett. 82, 2583 (1999)].Comment: 6 pages, including 7 figures, submitted to Phys. Rev.

Membranes for Topological M-Theory

We formulate a theory of topological membranes on manifolds with G_2 holonomy. The BRST charges of the theories are the superspace Killing vectors (the generators of global supersymmetry) on the background with reduced holonomy G_2. In the absence of spinning formulations of supermembranes, the starting point is an N=2 target space supersymmetric membrane in seven euclidean dimensions. The reduction of the holonomy group implies a twisting of the rotations in the tangent bundle of the branes with ``R-symmetry'' rotations in the normal bundle, in contrast to the ordinary spinning formulation of topological strings, where twisting is performed with internal U(1) currents of the N=(2,2) superconformal algebra. The double dimensional reduction on a circle of the topological membrane gives the strings of the topological A-model (a by-product of this reduction is a Green-Schwarz formulation of topological strings). We conclude that the action is BRST-exact modulo topological terms and fermionic equations of motion. We discuss the role of topological membranes in topological M-theory and the relation of our work to recent work by Hitchin and by Dijkgraaf et al.Comment: 22 pp, plain tex. v2: refs. adde

Effective Nucleon-Nucleon Interaction and Fermi Liquid Theory

We present two novel relations between the quasiparticle interaction in nuclear matter and the unique low momentum nucleon-nucleon interaction in vacuum. These relations provide two independent constraints on the Fermi liquid parameters of nuclear matter. Moreover, the new constraints define two combinations of Fermi liquid parameters, which are invariant under the renormalization group flow in the particle-hole channels. Using empirical values for the spin-independent Fermi liquid parameters, we are able to compute the major spin-dependent ones by imposing the new constraints as well as the Pauli principle sum rules.Comment: 4 pages, 5 figures, in Proc. 11th International Conference on Recent Progress in Many-Body Theories, Manchester, UK, July 9-13, 200

Compression Ratio Influence on Maximum Load of a Natural Gas Fueled HCCI Engine

This paper discusses the compression ratio influence on maximum load of a Natural Gas HCCI engine. A modified Volvo TD100 truck engine is controlled in a closed-loop fashion by enriching the Natural Gas mixture with Hydrogen. The first section of the paper illustrates and discusses the potential of using hydrogen enrichment of natural gas to control combustion timing. Cylinder pressure is used as the feedback and the 50 percent burn angle is the controlled parameter. Full-cycle simulation is compared to some of the experimental data and then used to enhance some of the experimental observations dealing with ignition timing, thermal boundary conditions, emissions and how they affect engine stability and performance. High load issues common to HCCI are discussed in light of the inherent performance and emissions tradeoff and the disappearance of feasible operating space at high engine loads. The problems of tighter limits for combustion timing, unstable operational points and physical constraints at high loads are discussed and illustrated by experimental results. Finally, the influence on operational limits, i.e., emissions peak pressure rise and peak cylinder pressure, from compression ratio at high load are discussed