1,282 research outputs found
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 () and charged ()
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 () 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 and
. 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 be an abelian extension. The purpose of this
paper is to study the problem of extending automorphisms of and lifting
automorphisms of to certain automorphisms of .Comment: 11 page
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