1,677 research outputs found
Renormalized Thermodynamic Entropy of Black Holes in Higher Dimensions
We study the ultraviolet divergent structures of the matter (scalar) field in
a higher D-dimensional Reissner-Nordstr\"{o}m black hole and compute the matter
field contribution to the Bekenstein-Hawking entropy by using the Pauli-Villars
regularization method. We find that the matter field contribution to the black
hole entropy does not, in general, yield the correct renormalization of the
gravitational coupling constants. In particular we show that the matter field
contribution in odd dimensions does not give the term proportional to the area
of the black hole event horizon.Comment: Final Revision Form as to be published in Physical Review D, ReVTeX,
No Figure
Black Hole Formation by Sine-Gordon Solitons in Two-dimensional Dilaton Gravity
The CGHS model of two-dimensional dilaton gravity coupled to a sine-Gordon
matter field is considered. The theory is exactly solvable classically, and the
solutions of a kink and two-kink type solitons are studied in connection with
black hole formation.Comment: 11 pages, no figures, revte
Fatigue Equivalent Stress State Approach Validation in Non-conservative Criteria: a Comparative Study
Synchronization and resonance in a driven system of coupled oscillators
We study the noise effects in a driven system of globally coupled
oscillators, with particular attention to the interplay between driving and
noise. The self-consistency equation for the order parameter, which measures
the collective synchronization of the system, is derived; it is found that the
total order parameter decreases monotonically with noise, indicating overall
suppression of synchronization. Still, for large coupling strengths, there
exists an optimal noise level at which the periodic (ac) component of the order
parameter reaches its maximum. The response of the phase velocity is also
examined and found to display resonance behavior.Comment: 17 pages, 3 figure
Boundary degrees of freedom in fractional quantum Hall effect: Excitations on common boundary of two samples
Using the Carlip's method we have derived the boundary action for the fermion
Chern-Simons theory of quantum Hall effects on a planar region with a boundary.
We have computed both the bulk and edge responses of currents to the external
electric field. From this we obtain the well-known anomaly relation and the
boundary Hall current without introducing any ad hoc assumptions such as the
chirality condition. In addition, the edge current on the common boundary of
two samples is found to be proportional to the difference between Chern-Simons
coupling strengths.Comment: 20 pages, uses revte
Comprehensive analysis of risk factors associating with Hepatitis B virus (HBV) reactivation in cancer patients undergoing cytotoxic chemotherapy
Phosphor-Free Apple-White LEDs with Embedded Indium-Rich Nanostructures Grown on Strain Relaxed Nano-epitaxy GaN
Phosphor-free apple-white light emitting diodes have been fabricated using a dual stacked InGaN/GaN multiple quantum wells comprising of a lower set of long wavelength emitting indium-rich nanostructures incorporated in multiple quantum wells with an upper set of cyan-green emitting multiple quantum wells. The light-emitting diodes were grown on nano-epitaxially lateral overgrown GaN template formed by regrowth of GaN over SiO2 film patterned with an anodic aluminum oxide mask with holes of 125 nm diameter and a period of 250 nm. The growth of InGaN/GaN multiple quantum wells on these stress relaxed low defect density templates improves the internal quantum efficiency by 15% for the cyan-green multiple quantum wells. Higher emission intensity with redshift in the PL peak emission wavelength is obtained for the indium-rich nanostructures incorporated in multiple quantum wells. The quantum wells grown on the nano-epitaxially lateral overgrown GaN has a weaker piezoelectric field and hence shows a minimal peak shift with application of higher injection current. An enhancement of external quantum efficiency is achieved for the apple-white light emitting diodes grown on the nano-epitaxially lateral overgrown GaN template based on the light -output power measurement. The improvement in light extraction efficiency, ηextraction, was found to be 34% for the cyan-green emission peak and 15% from the broad long wavelength emission with optimized lattice period
Realizations of Real Low-Dimensional Lie Algebras
Using a new powerful technique based on the notion of megaideal, we construct
a complete set of inequivalent realizations of real Lie algebras of dimension
no greater than four in vector fields on a space of an arbitrary (finite)
number of variables. Our classification amends and essentially generalizes
earlier works on the subject.
Known results on classification of low-dimensional real Lie algebras, their
automorphisms, differentiations, ideals, subalgebras and realizations are
reviewed.Comment: LaTeX2e, 39 pages. Essentially exetended version. Misprints in
Appendix are correcte
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