Dynamic Density Response of Trapped Interacting Quantum Gases

An expression for the dynamic density response function has been obtained for an interacting quantum gas in Random Phase Approximation (RPA) including first order self and exchange contribution. It involves the single particle wave functions and eigen values. The expression simplifies when diagonal elements are considered. The diagonal elements of the imaginary part of Fourier transformed response function is relevant in the measurement of Bragg scattering cross-section and in several other applications.Comment: 2 pages, 0 figure, conferenc

Dependence of structure factor and correlation energy on the width of electron wires

The structure factor and correlation energy of a quantum wire of thickness $b\ll a_B$ are studied in random phase approximation and for the less investigated region $r_s<1$. Using the single-loop approximation, analytical expressions of the structure factor have been obtained. The exact expressions for the exchange energy are also derived for a cylindrical and harmonic wire. The correlation energy $\epsilon_c$ is found to be represented by $\epsilon_c (b,r_s)= \frac{\alpha(r_s)}{b} + \beta(r_s)\; ln(b) + \eta(r_s)$, for small $b$ and high densities. For a pragmatic width of the wire, the correlation energy is in agreement with the quantum Monte Carlo simulation data.Comment: Being slightly modifie

Radiation reaction in the 2.5PN waveform from inspiralling binaries in circular orbits

In this Comment we compute the contributions of the radiation reaction force in the 2.5 post-Newtonian (PN) gravitational wave polarizations for compact binaries in circular orbits. (i) We point out and correct an inconsistency in the derivation of Arun, Blanchet, Iyer, and Qusailah. (ii) We prove that all contributions from radiation reaction in the 2.5PN waveform are actually negligible since they can be absorbed into a modification of the orbital phase at the 5PN order.Comment: 7 pages, no figures, submitted to CQ

Importance of Technological Innovation for SME Growth: Evidence from India

This paper probes the drivers, dimensions, achievements, and outcomes of technological innovations carried out by SMEs in the auto components, electronics, and machine tool sectors of Bangalore in India. Further, it ascertains the growth rates of innovative SMEs vis-à-vis non-innovative SMEs in terms of sales turnover, employment, and investment. Thereafter, it probes the relationship between innovation and growth of SMEs by (i) estimating a correlation between innovation sales and sales growth, (ii) calculating innovation sales for high, medium, and low growth innovative SMEs and doing a aggregate one-way ANOVA, and (iii) ascertaining the influence of innovation sales, along with investment growth and employment growth on gross value-added growth by means of multiple regression analysis. The paper brings out substantial evidence to argue that innovations of SMEs contributed to their growth.Technological innovations, sales growth, auto components, electronics, machine tools, Bangalore

Board Interlocks and Their Impact on Corporate Governance: The Indian Experience - Coping with Corporate Cholesterol

Board interlocks occur when a director of one organization sits on the board of directors of another organization. The causes and consequences of these interlocks have been much debated in the western literature but comparatively little is known about interlocks in Indian corporate boards. Board interlocks are essentially analogous to cholesterol. Both are facts of life. Like good cholesterol, there are aspects of interlocking directorates that are beneficial and there are others that are detrimental to the corporation and its stakeholders and their respective interests. In this study, we find that board interlocks are quite widespread in India. Taking a (numerically) small but nevertheless (in terms of market capitalization) an important slice of available corporate data, we observed that in 2010, ‘highly boarded’ directors (defined as those on the board of 5 or more listed NSE companies) who constitute just 6 percent of the overall pool of directors among NSE100 companies are associated with 486 NSE listed companies which account for a whopping 66 percent of the total market capitalization of all NSE listed companies. Interestingly, there appears to be a marked increase in market capitalization of these ‘highly boarded’ companies, which these ‘highly boarded’ directors are linked to over the last several years. For instance, for the 3 years from 2001 to 2003, the market capitalization of ‘highly boarded’ companies ranged between 33 percent to 43 percent; it moved up to peak of 70 percent in 2007 and was at 66 percent in 2010 (the latest year in the study period). The substantive rise in market capitalization of these ‘highly boarded’ companies has coincided with only a marginal increase (from 5% to 6%) in the proportion of ‘highly boarded’ directorships. These trends suggest that despite the well-intentioned regulatory reforms (a) the extent of over-boarding/interlocking among directors has not come down (there is actually a marginal increase) and (b) there appears to be increasing concentration of power among key individuals. Given the general view that concentration of power in a few individuals or entities is not desirable in the larger interests of society, it would appear that the observed trends in the concentration of power among a handful of the country’s corporate elite is a matter for substantive public policy concern. Finally, the regression analysis indicates a positive impact on Return on Assets (ROA) for ‘highly boarded’ directors signifying a negation of the agency centric conceptualization on the role of multiple directors. Instead, connectedness variables (Eigen vector) which proxy for the Resource dependency hypothesis are quite strongly supported. In a nutshell, from public policy perspective, the analysis potentially reflects the ‘bad cholesterol’ elements of multiple directorships in terms of a tiny segment of ‘highly boarded’ directors controlling a significant portion of the country’s economic prowess, whereas the positive influences on company performance provide some evidence of the ‘good cholesterol’.