2,918 research outputs found
On integrability of the Yao-Zeng two-component short-pulse equation
We show how the Yao-Zeng system of coupled short-pulse equations is related
to the original short-pulse equation and obtain the correct zero-curvature
representation of the Yao-Zeng system via this relationship.Comment: 5 page
Multi loop soliton solutions and their interactions in the Degasperis-Procesi equation
In this article, we construct loop soliton solutions and mixed soliton - loop
soliton solution for the Degasperis-Procesi equation. To explore these
solutions we adopt the procedure given by Matsuno. By appropriately modifying
the -function given in the above paper we derive these solutions. We
present the explicit form of one and two loop soliton solutions and mixed
soliton - loop soliton solutions and investigate the interaction between (i)
two loop soliton solutions in different parametric regimes and (ii) a loop
soliton with a conventional soliton in detail.Comment: Published in Physica Scripta (2012
Hawking radiation as tunneling from squashed Kaluza-Klein black hole
We discuss Hawking radiation from a five-dimensional squashed Kaluza-Klein
black hole on the basis of the tunneling mechanism. A simple manner, which was
recently suggested by Umetsu, is possible to extend the original derivation by
Parikh and Wilczek to various black holes. That is, we use the two-dimensional
effective metric, which is obtained by the dimensional reduction near the
horizon, as the background metric. By using same manner, we derive both the
desired result of the Hawking temperature and the effect of the back reaction
associated with the radiation in the squashed Kaluza-Klein black hole
background.Comment: 16 page
A direct method of solution for the Fokas-Lenells derivative nonlinear Schr\"odinger equation: I. Bright soliton solutions
We develop a direct method of solution for finding the bright -soliton
solution of the Fokas-Lenells derivative nonlinear Schr\"odinger equation. The
construction of the solution is performed by means of a purely algebraic
procedure using an elementary theory of determinants and does not rely on the
inverse scattering transform method. We present two different expressions of
the solution both of which are expressed as a ratio of determinants. We then
investigate the properties of the solutions and find several new features.
Specifically, we derive the formula for the phase shift caused by the
collisions of bright solitons.Comment: To appear in J. Phys. A: Math. Theor. 45(2012) Ma
Use of untreated wastewater in peri-urban agriculture in Pakistan: risks and opportunities
Water reuse / Waste waters / Water quality / Groundwater / Irrigation practices / Soil properties / Environmental effects / Conjunctive use / Pakistan / Haroonabad
A new ultra high energy gamma ray telescope at Ohya mine
The search for ultra high energy gamma rays coming from point sources is one of the main experimental aims. A fast air shower timing system was constructed at ICRR for the study of the angular resolution of the system and operated approximately half a year. The characteristics of the surface array of Ohya air shower telescope is described
Charge ordering in the spinels AlVO and LiVO
We develop a microscopic theory for the charge ordering (CO) transitions in
the spinels AlVO and LiVO (under pressure). The high degeneracy
of CO states is lifted by a coupling to the rhombohedral lattice deformations
which favors transition to a CO state with inequivalent V(1) and V(2) sites
forming Kagom\'e and trigonal planes respectively. We construct an extended
Hubbard type model including a deformation potential which is treated in
unrestricted Hartree Fock approximation and describes correctly the observed
first-order CO transition. We also discuss the influence of associated orbital
order. Furthermore we suggest that due to different band fillings AlVO
should remain metallic while LiVO under pressure should become a
semiconductor when charge disproportionation sets in
Electronic states and magnetic excitations in LiV2O4: Exact diagonalization study
Motivated by recent inelastic neutron scattering experiment we examine
magnetic properties of LiV2O4. We consider a model which describes the
half-filled localized A1g spins interacting via frustrated antiferromagnetic
Heisenberg exchange and coupled by local Hund's interaction with the 1/8-filled
itinerant Eg band, and study it within an exact diagonalization scheme. In the
present study we limited the analysis to the case of the cluster of two
isolated tetrahedrons. We obtained that both the ground state structure and
low-lying excitations depend strongly on the value of the Hund's coupling which
favors the triplet states. With increasing temperature the triplet states
become more and more populated which results in the formation of non-zero
residual magnetic moment. We present the temperature dependence of calculated
magnetic moment and of the spin-spin correlation functions at different values
of Hund's coupling and compare them with the experimental results.Comment: 7 pages. 6 eps figure
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