Spontaneous Left-Right Symmetry Breaking in Supersymmetric Models with only Higgs Doublets

We studied the question of parity breaking in a supersymmetric left-right model, in which the left-right symmetry is broken with Higgs doublets (carrying $B-L=\pm 1$). Unlike the left-right symmetric models with triplet Higgs scalars (carrying $B-L=\pm 2$), in this model it is possible to break parity spontaneously by adding a parity odd singlet. We then discussed how neutrino mass of type III seesaw can be invoked in this model by adding extra fermion singlets. We considered simple forms of the mass matrices that are consistent with the unification scheme and demonstrate how they can reproduce the required neutrino mixing matrix. In this model, the baryon asymmetry of the universe is generated via leptogenesis. The required mass scales in the model is then found to be consistent with the gauge coupling unification.Comment: 19 pages, 1 eps figur

Debt and Corporate Governance in Emerging Economies - Evidence from India

We analyze the role of debt in corporate governance with respect to a large emerging economy, India, where debt has been an important source of external finance. First, we examine the extent to which debt acts as a disciplining device in those corporations where potential for over investment is present. We undertake a comparative evaluation of group-affiliated and non-affiliated companies to see if the governance role of debt is sensitive to ownership and control structures. Second, we examine the role of institutional change in strengthening the disciplining effect or mitigating the expropriating effect of debt. In doing so, we estimate, simultaneously, the relation between Tobins Q and leverage using a large cross-section of listed manufacturing firms in India for three years, 1996, 2000, and 2003. Our analyses indicate that while in the early years of institutional change, debt did not have any disciplinary effect on either standalone or group affiliated firms, the disciplinary effect appeared in the later years as institutions become more market oriented. We also find limited evidence of debt being used as an expropriation mechanism in group firms that are more vulnerable to such expropriation. However, the disciplining effect of debt is found to persist even after controlling for such expropriation possibilities. In general, our results highlight the role of ownership structures and institutions in debt governance.Debt, ownership structure, Corporate governance, institutional change.

Multiple board appointments and firm performance in emerging economies: Evidence from India

The relation between multiple directorships, busy directors and firm performance has been researched predominantly in the context of developed economies, notably the US. This paper extends the existing literature on multiple directorships in two ways; first, by providing additional evidence on its effect on firm performance, but with respect to an emerging economy, India, and secondly, by suggesting an alternative measure of directorial "busyness" that is more general in its applicability compared to those that have been applied in the existing literature. Using a sample of 500 large firms from the Indian corporate sector for the year 2002-03, the paper finds multiple directorships by independent directors to correlate positively with firm value thereby supporting the "quality hypothesis" that busy directors are likely to be better directors, a result that is different from the existing evidence on busy directors. Multiple directorships by insider directors are, however, negatively related to firm performance. Estimation of group and non-group companies separately reveals that the quality effect of independent directors persists for the former but disappears for the latter. In general, the results suggest that the relation between "busy" directors and firm performance may depend on the institutional context and on the type of directorMultiple Directorships, Busy Directors, Firm Performance

Maslov index formulas for Whitney n-gons

In this short article, we find an explicit formula for Maslov index of Whitney n-gons joining intersections points of n half-dimensional tori in the symmetric product of a surface. The method also yields a formula for the intersection number of such an n-gon with the fat diagonal in the symmetric product

Delocalization of charge and current in a chiral quasiparticle wave-packet

A chiral quasi-particle wave packet (c-QPWP) is defined as a conventional superposition of chiral quasi-particle states corresponding to an interacting electron system in two dimensions (2D) in the presence of Rashba spin-orbit coupling (RSOC). I investigate its internal structure via studying the charge and the current densities within the first order perturbation in the electron-electron interaction. It is found that the c-QPWP contains a localized charge which is less than the magnitude of the bare charge and the remaining charge resides at the system boundary. The amount of charge delocalized turns out to be inversely proportional to the degenerate Fermi velocity $v_0 ( = \sqrt{\alpha^2 + 2\mu / m})$ when RSOC (with strength $\alpha$) is weak, and therefore externally tunable. For strong RSOC, the magnitudes of both the delocalized charge and the current further strongly depend on the direction of propagation of the wave packet. Both the charge and the current densities consist of an anisotropic $r^{-2}$ tail away from the centre of the wave packet. Possible implications of such delocalizations in real systems corresponding to 2D semiconductor heterostructure are also discussed within the context of particle injection experiments.Comment: 19 pages, 6 figures, Version accepted for publication in Phys. Rev. B, typos correcte