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How does ownership structure affect capital structure and firm performance? Recent evidence from east Asia
The present paper empirically examines the effects of ownership
structure on capital structure and firm valuation in four East Asian countries worst
affected by the last Crisis. In doing so, we distinguish ownership from both control
and management and also allow for the simultaneity between capital structure and
firm valuation in the sample countries. Results obtained from 3SLS estimates with
error components confirm and extend the findings of Claessens et al. (2002) and
particularly highlight the contrasting behaviour of family firms and non-family firms
with/without a Cronyman
A semi-analytical approach to perturbations in mutated hilltop inflation
We study cosmological perturbations and observational aspects for mutated
hilltop model of inflation. Employing mostly analytical treatment, we evaluate
observable parameters during inflation as well as post-inflationary
perturbations. This further leads to exploring observational aspects related to
Cosmic Microwave Background (CMB) radiation. This semi-analytical treatment
reduces complications related to numerical computation to some extent for
studying the different phenomena related to CMB angular power spectrum for
mutated hilltop inflation.Comment: 7 pages, 2 figures. Improved version to appear in IJMP
Evolution of superconductivity in PrFe1-xCoxAsO with x = 0.0 to 1.0
We report the synthesis and physical property characterization of
PrFe1-xCoxAsO with x = 0.0 to 1.0. The studied samples are synthesized by solid
state reaction route via vacuum encapsulation method. The pristine compound
PrFeAsO does not show superconductivity, but rather exhibits a metallic step
like transition due to spin density wave ordering of Fe moments below 150 K,
followed by another upward step due to anomalous ordering of Pr moments at 12
K. Both the Fe-SDW and Pr-TN temperatures decrease monotonically with Co
substitution at Fe site. Superconductivity appears in a narrow range of x from
0.07 to 0.25 with maximum Tc at 11.12 K for x = 0.15. Samples, with x = 0.25
exhibit metallic behavior right from 300 K down to 2 K, without any Fe-SDW or
Pr-TN steps in resistivity. In fact, though Fe-SDW decreases monotonically, the
Pr-TN is disappeared even with x = 0.02. The magneto transport measurements
below 14 Tesla on superconducting polycrystalline Co doped PrFeAsO lead to
extrapolated values of the upper critical fields [Hc2(0)] of up to 60 Tesla.Comment: 15 pages Text+Fig
Resistivity of non-Galilean-invariant Fermi- and non-Fermi liquids
While it is well-known that the electron-electron (\emph{ee}) interaction
cannot affect the resistivity of a Galilean-invariant Fermi liquid (FL), the
reverse statement is not necessarily true: the resistivity of a
non-Galilean-invariant FL does not necessarily follow a T^2 behavior. The T^2
behavior is guaranteed only if Umklapp processes are allowed; however, if the
Fermi surface (FS) is small or the electron-electron interaction is of a very
long range, Umklapps are suppressed. In this case, a T^2 term can result only
from a combined--but distinct from quantum-interference corrections-- effect of
the electron-impurity and \emph{ee} interactions. Whether the T^2 term is
present depends on 1) dimensionality (two dimensions (2D) vs three dimensions
(3D)), 2) topology (simply- vs multiply-connected), and 3) shape (convex vs
concave) of the FS. In particular, the T^2 term is absent for any quadratic
(but not necessarily isotropic) spectrum both in 2D and 3D. The T^2 term is
also absent for a convex and simply-connected but otherwise arbitrarily
anisotropic FS in 2D. The origin of this nullification is approximate
integrability of the electron motion on a 2D FS, where the energy and momentum
conservation laws do not allow for current relaxation to leading
--second--order in T/E_F (E_F is the Fermi energy). If the T^2 term is
nullified by the conservation law, the first non-zero term behaves as T^4. The
same applies to a quantum-critical metal in the vicinity of a Pomeranchuk
instability, with a proviso that the leading (first non-zero) term in the
resistivity scales as T^{\frac{D+2}{3}} (T^{\frac{D+8}{3}}). We discuss a
number of situations when integrability is weakly broken, e.g., by inter-plane
hopping in a quasi-2D metal or by warping of the FS as in the surface states of
Bi_2Te_3 family of topological insulators.Comment: Submitted to a special issue of the Lithuanian Journal of Physics
dedicated to the memory of Y. B. Levinso
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