Rational approximations to the solution of the second order Ricatti equation Technical report, 15 Jan. - 14 Oct. 1965

Rational approximations to solution of second order nonlinear Ricatti equation, using linear transformations - differential equations and operational calculu

Rational approximations to the generalized Duffing equation Final report, 15 Jan. - 1965 - 14 Jan. 1966

Linear transformation to obtain rational approximation to response of physical system described by nonlinear differential equation including Duffing equation as special cas

Analytical Expression for the RKKY Interaction in Doped Graphene

We obtain an analytical expression for the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction $J$ in electron or hole doped graphene for linear Dirac bands. The results agree very well with the numerical calculations for the full tight-binding band structure in the regime where the linear band structure is valid. The analytical result, expressed in terms of the Meijer G-function, consists of a product of two oscillatory terms, one coming from the interference between the two Dirac cones and the second coming from the finite size of the Fermi surface. For large distances, the Meijer G-function behaves as a sinusoidal term, leading to the result $J \sim R^{-2} k_F \sin (2 k_F R) {1 + \cos[(K-K').R]}$ for moments located on the same sublattice. The $R^{-2}$ dependence, which is the same for the standard two-dimensional electron gas, is universal irrespective of the sublattice location and the distance direction of the two moments except when $k_F =0$ (undoped case), where it reverts to the $R^{-3}$ dependence. These results correct several inconsistencies found in the literature.Comment: 5 pages, 5 figure

The Use of Code-Mixing Among Pamonanese in Parata Ndaya Closed-Group Facebook

Research intended to figure out why Pamonanes did code-mixing in Parata Ndaya, a Facebook closed-group site. The research applied qualitative method to get the types of code-mixing and reasons for doing code-mixing, while the analysis used Hoffman\u27s theory. Data were taken from comments of three active members of Parata Ndaya. Comments selected were mainly focused on political issues that happened during Regional House Representative Election in 2014. Data analysis reveals that code-mixing is mostly found in jokes and some comments about political leaders. Thus, the results can provide insights for Parata Ndaya members to build awareness on preserving their local language (i.e. Pamona language) as well as to enhance solidarity among members of the group site

Recent Progress in Heavy Quark Physics

Some of the recent progress in heavy quark physics is reviewed. Special attention is paid to inclusive methods for determining Vub and factorization in nonleptonic B decays. Theoretical predictions for top-antitop production near threshold are also discussed.Comment: talk given at 2001 Lepton Photon Meeting, 10 pages, 5 figure

Magnetic Ground State of Pr0.89_{0.89}LaCe0.11_{0.11}CuO4+α−δ_{4+\alpha-\delta} with Varied Oxygen Depletion Probed by Muon Spin Relaxation

The magnetic ground state of an electron-doped cuprate superconductor Pr$_{1-x}$LaCe$_x$CuO$_{4+\alpha-\delta}$ ($x=0.11, \alpha\simeq0.04$) has been studied by means of muon spin rotation/relaxation (\msr) over a wide variety of oxygen depletion, $0.03\le\delta\le0.12$. Appearance of weak random magnetism over entire crystal volume has been revealed by a slow exponential relaxation. The absence of $\delta$-dependence for the random magnetism and the multiplet pattern of muon Knight shift at higher fields strongly suggest that the random moments are associated with excited Pr$^{3+}$ ions under crystal electric field.Comment: 6 pages, 4 figures, submitted to J. Phys. Soc. Jp