Notes on highest weight modules of the elliptic algebra Aq,p(sl^2){\cal A}_{q,p}\left(\widehat{sl}_2\right)

We discuss a construction of highest weight modules for the recently defined elliptic algebra ${\cal A}_{q,p}(\widehat{sl}_2)$, and make several conjectures concerning them. The modules are generated by the action of the components of the operator $L$ on the highest weight vectors. We introduce the vertex operators $\Phi$ and $\Psi^*$ through their commutation relations with the $L$-operator. We present ordering rules for the $L$- and $\Phi$-operators and find an upper bound for the number of linearly independent vectors generated by them, which agrees with the known characters of $\widehat{sl}_2$-modules.Comment: Nonstandard macro package eliminate

Fundamental Vibrational Transitions of HCl Detected in CRL 2136

We would like to understand the chemistry of dense clouds and their hot cores more quantitatively by obtaining more complete knowledge of the chemical species present in them. We have obtained high-resolution infrared absorption spectroscopy at 3-4 um toward the bright infrared source CRL 2136. The fundamental vibration-rotation band of HCl has been detected within a dense cloud for the first time. The HCl is probably located in the warm compact circumstellar envelope or disk of CRL 2136. The fractional abundance of HCl is (4.9-8.7)e-8, indicating that approximately 20 % of the elemental chlorine is in gaseous HCl. The kinetic temperature of the absorbing gas is 250 K, half the value determined from infrared spectroscopy of 13CO and water. The percentage of chlorine in HCl is approximately that expected for gas at this temperature. The reason for the difference in temperatures between the various molecular species is unknown.Comment: 6 pages, 3 figures, A&A in pres

A remark on the Hankel determinant formula for solutions of the Toda equation

We consider the Hankel determinant formula of the $\tau$ functions of the Toda equation. We present a relationship between the determinant formula and the auxiliary linear problem, which is characterized by a compact formula for the $\tau$ functions in the framework of the KP theory. Similar phenomena that have been observed for the Painlev\'e II and IV equations are recovered. The case of finite lattice is also discussed.Comment: 14 pages, IOP styl

Description of Pseudo-Newtonian Potential for the Relativistic Accretion Disk around Kerr Black Holes

We present a pseudo-Newtonian potential for accretion disk modeling around the rotating black holes. This potential can describe the general relativistic effects on accretion disk. As the inclusion of rotation in a proper way is very important at an inner edge of disk the potential is derived from the Kerr metric. This potential can reproduce all the essential properties of general relativity within 10% error even for rapidly rotating black holes.Comment: 5 Latex pages including 1 figure. Version to appear in Astrophysical Journal, V-581, N-1, December 10, 200

RF amplification property of the MgO-based magnetic tunnel junction using field-induced ferromagnetic resonance

The radio-frequency (RF) voltage amplification property of a tunnel magnetoresistance device driven by an RF external-magnetic-field-induced ferromagnetic resonance was studied. The proposed device consists of a magnetic tunnel junction (MTJ) and an electrically isolated coplanar waveguide. The input RF voltage applied to the waveguide can excite the resonant dynamics in the free layer magnetization, leading to the generation of an output RF voltage under a DC bias current. The dependences of the RF voltage gain on the static external magnetic field strength and angle were systematically investigated. The design principles for the enhancement of the gain factor are also discussed.Comment: 12 pages, 3 figure

Heat operator with pure soliton potential: properties of Jost and dual Jost solutions

Properties of Jost and dual Jost solutions of the heat equation, $\Phi(x,k)$ and $\Psi(x,k)$, in the case of a pure solitonic potential are studied in detail. We describe their analytical properties on the spectral parameter $k$ and their asymptotic behavior on the $x$-plane and we show that the values of $e^{-qx}\Phi(x,k)$ and the residua of $e^{qx}\Psi(x,k)$ at special discrete values of $k$ are bounded functions of $x$ in a polygonal region of the $q$-plane. Correspondingly, we deduce that the extended version $L(q)$ of the heat operator with a pure solitonic potential has left and right annihilators for $q$ belonging to these polygonal regions.Comment: 26 pages, 3 figure

Evidence for suppressed metallicity on the surface of La2-xSrxCuO4 and Nd2-xCexCuO4

Hard X-ray Photoemission spectroscopy (PES) of copper core electronic states, with a probing depth of $\sim$60 \AA, is used to show that the Zhang-Rice singlet feature is present in La$_2$CuO$_4$ but is absent in Nd$_2$CuO$_4$. Hole- and electron doping in La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) and Nd$_{2-x}$Ce$_x$CuO$_4$ (NCCO) result in new well-screened features which are missing in soft X-ray PES. Impurity Anderson model calculations establish metallic screening as its origin, which is strongly suppressed within 15 $\text{\AA}$ of the surface. Complemented with X-ray absorption spectroscopy, the small chemical-potential shift in core levels ($\sim0.2$ eV) are shown to be consistent with modifications of valence and conduction band states spanning the band gap ($\sim1$ eV) upon hole- and electron-doping in LSCO and NCCO.Comment: 4 pages, 4 figure

Stability of accretion disk around rotating black holes: a pseudo-general-relativistic fluid dynamical study

We discuss the solution of accretion disk when the black hole is chosen to be rotating. We study, how the fluid properties get affected for different rotation parameters of the black hole. We know that no cosmic object is static in Universe. Here the effect of the rotation of the black hole to the space-time is considered following an earlier work of the author, where the pseudo-Newtonian potential was prescribed for the Kerr geometry. We show that, with the inclusion of rotation of the black hole, the valid disk parameter region dramatically changes and disk becomes unstable. Also we discuss about the possibility of shock in accretion disk around rotating black holes. When the black hole is chosen to be rotating, the sonic locations of the accretion disk get shifted or disappear, making the disk unstable. To bring it in the stable situation, the angular momentum of the accreting matter has to be reduced/enhanced (for co/counter-rotating disk) by means of some physical process.Comment: 24 Latex pages including 7 figures; Accepted for publication in Astrophysical Journa

Bulk screening in core level photoemission from Mott-Hubbard and Charge-Transfer systems

We report bulk-sensitive hard X-ray ($h\nu$ = 5.95 KeV) core level photoemission spectroscopy (PES) of single crystal V$_{1.98}$Cr$_{0.02}$O$_{3}$ and the high-$T_c$ cuprate Bi$_2$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ (Bi2212). V$_{1.98}$Cr$_{0.02}$O$_{3}$ exhibits low binding energy "satellites" to the V $2p$ "main lines" in the metallic phase, which are suppressed in the antiferromagnetic insulator phase. In contrast, the Cu $2p$ spectra of Bi2212 do not show temperature dependent features, but a comparison with soft X-ray PES indicates a large increase in the $2p^5 3d^9$ "satellites" or $3d^9$ weight in the bulk. Cluster model calculations, including full multiplet structure and a screening channel derived from the coherent band at the Fermi energy, give very satisfactory agreement with experiments