Conformal Orthosymplectic Quantum Mechanics

We present the most general curvature obstruction to the deformed parabolic orthosymplectic symmetry subalgebra of the supersymmetric quantum mechanical models recently developed to describe Lichnerowicz wave operators acting on arbitrary tensors and spinors. For geometries possessing a hypersurface-orthogonal homothetic conformal Killing vector we show that the parabolic subalgebra is enhanced to a (curvature-obstructed) orthosymplectic algebra. The new symmetries correspond to time-dependent conformal symmetries of the underlying particle model. We also comment on generalizations germane to three dimensions and new Chern--Simons-like particle models.Comment: 27 pages LaTe

It takes a village to raise a tide: nonlinear multiple-mode coupling and mode identification in KOI-54

We explore the tidal excitation of stellar modes in binary systems using Kepler observations of the remarkable eccentric binary KOI-54 (HD 187091; KIC 8112039), which displays strong ellipsoidal variation as well as a variety of linear and nonlinear pulsations. We report the amplitude and phase of over 120 harmonic and anharmonic pulsations in the system. We use pulsation phases to determine that the two largest-amplitude pulsations, the 90th and 91st harmonics, most likely correspond to axisymmetric m=0 modes in both stars, and thus cannot be responsible for resonance locks as had been recently proposed. We find evidence that the amplitude of at least one of these two pulsations is decreasing with a characteristic timescale of ~100 yr. We also use the pulsations' phases to confirm the onset of the traveling wave regime for harmonic pulsations with frequencies <~50 Omega_orbit, in agreement with theoretical expectations. We present evidence that many pulsations that are not harmonics of the orbital frequency correspond to modes undergoing simultaneous nonlinear coupling to multiple linearly driven parent modes. Since coupling among multiple modes can lower the threshold for nonlinear interactions, nonlinear phenomena may be easier to observe in highly eccentric systems, where broader arrays of driving frequencies are available. This may help to explain why the observed amplitudes of the linear pulsations are much smaller than the theoretical threshold for decay via three-mode coupling.Comment: Accepted for publication in MNRAS. Only minor corrections. 16 Pages; 8 Figures; 3 Table

One Share - One Vote: The Theory

The impact of separating cash flow and votes depends on the ownership structure. In widely held firms, one share - one vote is in general not optimal. While it ensures an efficient outcome in bidding contests, dual-class shares mitigate the free-rider problem, thereby promoting takeovers. In the presence of a controlling shareholder, one share - one vote promotes value-increasing control transfers and deters value-decreasing control transfers more effectively than any other vote allocation. Moreover, leveraging the insider's voting power aggravates agency conflicts because it protects her from the takeover threat and provides less alignment with other shareholders. Even so, minority shareholder protection is not a compelling argument for regulatory intervention, as rational investors anticipate the insider's opportunism. Rather, the rationale for mandating one share – one vote must be to disempower controlling minority shareholders in order to promote value-increasing takeovers. As this policy tends to empower managers vis-a-vis shareholders, it is an open question whether it would improve the quality of corporate governance, notably in systems built around large active owners. The verdict in the case of depositary certificates, priority shares, voting and ownership ceilings is less I ambiguous, since they insulate managers from both takeovers and effective shareholder monitoring.Security-voting structure; market for corporate control; controlling minority shareholders

The Role of Accounting Conservatism in a well-functioning Corporate Governance System

This paper analyses accounting related to corporate governance and is organized as follows. The first section deals with understanding the concept of accounting conservatism. In the second section we analyzed the Relevance of Accounting Conservatism in Corporate Governance to the modern corporate world. The third section includes a Case Study on Ericsson, a Swedish Telecommunications company and conservatism in strong governance firms versus weak governance firms. The fourth part is devoted to the conclusion of our research efforts. From this study, we conclude that there are several reasons to use accounting conservatism in corporate governance and that current empirical evidence indicates that conservatism has increased in the last decades. The value of β3 in Table 1 indicates that there is a positive significant level of conservatism in accounting practices followed by Ericsson. When the dependent variable is earnings (X), the asymmetric timeliness of earnings coefficient β3 in Table 2 provides an estimate of the level of conservatism. We observe that strong governance firms are more conservative than weak governance firms (0.13 versus 0.04).corporate governance; financial system; accounting conservatism

Club Enlargement: Early Versus Late Admittance

Within an incomplete contract framework, we analyze the enlargement strategy of a club facing applicants that differ in wealth and reform status. While an applicant benefits from entry, the club only gains if the entrant makes an adjustment investment. The club has a choice between early admittance, using its limited internal enforcement powers to ensure reform, and late admittance conditional on prior reform. Wealthy candidates enter early as the club can charge a higher entrance fee for undiscounted membership benefits. For poor applicants, the club applies a reversed admittance order: A less advanced applicant is admitted early to reform as member, while a more advanced enters late after it has reformed. Moreover, the admittance rents increase in the ratio of reform distance to wealth. The viability of the late admittance strategy depends on the club's commitment ability. If the club can credibly commit to a stage-financing schedule, it can induce applicants to reform without overfunding. In the repeated game, the threat of denying additional funding is not credible, and more overfunding is required for reform.

Security-voting structure and bidder screening

This paper analyzes how non-voting shares affect the takeover outcome in a single-bidder model with asymmetric information and private benefit extraction. In equilibrium, the target firm’s security-voting structure influences the bidder’s participation constraint and in response the shareholders’ conditional expectations about the post-takeover share value. Therefore, the structure can be chosen to discriminate among bidder types. Typically, the socially optimal structure deviates from one share - one vote to promote all and only value-increasing bids. As target shareholders ignore takeover costs, they prefer more takeovers and hence choose a smaller fraction of voting shares than is socially optimal. In either case, the optimal fraction of voting shares decreases with the quality of shareholder protection and increases with the incumbent manager’s ability. Finally, shareholder returns are higher when a given takeover probability is implemented by (more) non-voting shares rather than by (larger) private benefits

Dynamical resonance locking in tidally interacting binary systems

We examine the dynamics of resonance locking in detached, tidally interacting binary systems. In a resonance lock, a given stellar or planetary mode is trapped in a highly resonant state for an extended period of time, during which the spin and orbital frequencies vary in concert to maintain the resonance. This phenomenon is qualitatively similar to resonance capture in planetary dynamics. We show that resonance locks can accelerate the course of tidal evolution in eccentric systems and also efficiently couple spin and orbital evolution in circular binaries. Previous analyses of resonance locking have not treated the mode amplitude as a fully dynamical variable, but rather assumed the adiabatic (i.e. Lorentzian) approximation valid only in the limit of relatively strong mode damping. We relax this approximation, analytically derive conditions under which the fixed point associated with resonance locking is stable, and further check these analytic results using numerical integrations of the coupled mode, spin, and orbital evolution equations. These show that resonance locking can sometimes take the form of complex limit cycles or even chaotic trajectories. We provide simple analytic formulae that define the binary and mode parameter regimes in which resonance locks of some kind occur (stable, limit cycle, or chaotic). We briefly discuss the astrophysical implications of our results for white dwarf and neutron star binaries as well as eccentric stellar binaries.Comment: 16 pages, 11 figure

Nitrate Reduction Approaches

Resource /Energy Economics and Policy, Q25,