Structural break, stability and demand for money in India

This paper attempts to take a meticulous look on stability of money demand in India Using annual data for period 1953-2007 and the Hansen (1992) and Gregory Hansen (1996) co-integration approaches with structural break. Results of the Gregory Hansen (1996) cointegration analysis show the presence of cointegration in demand for money, real GDP and nominal interest rate with structural break at 1965. Further, study also suggests for downward shift of about 0.33 % around 1965 in the demand for money function and put forward that demand for money is stable except for the period of 1975-1998.Money Demand; Cointegration with Structural Break; Stability; Choice of Monetary Instrument

Shallow Deep Transitions of Neutral and Charged Donor States in Semiconductor Quantum Dots

We carry out a detailed investigation of neutral ($D^0$) and charged ($D^-$) impurity states of hydrogen-like donors in spherical semiconductor quantum dots. The investigation is carried out within the effective mass theory (EMT). We take recourse to local density approximation (LDA) and the Harbola-Sahni (HS) schemes for treating many-body effects. We experiment with a variety of confining potentials: square, harmonic and triangular. We observe that the donor level undergoes shallow to deep transition as the dot radius ($R$) is reduced. On further reduction of the dot radius it becomes shallow again. We term this non-monotonic behaviour \textbf{SHADES}. This suggests the possibility of carrier {\textbf{\textit{``freeze out''}}} for both $D^0$ and $D^-$. Further, our study of the optical gaps also reveals a {\textbf{SHADES}} transition.Comment: 19 pages, 8 figures, Revised Versio

Better band gaps for wide-gap semiconductors from a locally corrected exchange-correlation potential that nearly eliminates self-interaction errors

This work constitutes a comprehensive and improved account of electronic-structure and mechanical properties of silicon-nitride (Si3N4) polymorphs via van Leeuwen and Baerends (LB) exchange-corrected local density approximation (LDA) that enforces the exact exchange potential asymptotic behavior. The calculated lattice constant, bulk modulus, and electronic band structure of Si3N4 polymorphs are in good agreement with experimental results. We also show that, for a single electron in a hydrogen atom, spherical well, or harmonic oscillator, the LB-corrected LDA reduces the (self-interaction) error to exact total energy to ~10%, a factor of three to four lower than standard LDA, due to a dramatically improved representation of the exchange-potential.Comment: 6 pages, 3 figure

Automorphisms of abelian group extensions

Let $1 \to N \to G \to H \to 1$ be an abelian extension. The purpose of this paper is to study the problem of extending automorphisms of $N$ and lifting automorphisms of $H$ to certain automorphisms of $G$.Comment: 11 page