A Dynamical System with Q-deformed Phase Space Represented in Ordinary Variable Spaces

Dynamical systems associated with a q-deformed two dimensional phase space are studied as effective dynamical systems described by ordinary variables. In quantum theory, the momentum operator in such a deformed phase space becomes a difference operator instead of the differential operator. Then, using the path integral representation for such a dynamical system, we derive an effective short-time action, which contains interaction terms even for a free particle with q-deformed phase space. Analysis is also made on the eigenvalue problem for a particle with q-deformed phase space confined in a compact space. Under some boundary conditions of the compact space, there arises fairly different structures from $q=1$ case in the energy spectrum of the particle and in the corresponding eigenspace .Comment: 17page, 2 figure

Early Spectral Evolution of the Rapidly Expanding Type Ia SN 2006X

We present optical spectroscopic and photometric observations of Type Ia supernova (SN) 2006X from --10 to +91 days after the $B$-band maximum. This SN exhibits one of the highest expansion velocity ever published for SNe Ia. At premaximum phases, the spectra show strong and broad features of intermediate-mass elements such as Si, S, Ca, and Mg, while the O{\sc i}$\lambda$7773 line is weak. The extremely high velocities of Si{\sc ii} and S{\sc ii} lines and the weak O{\sc i} line suggest that an intense nucleosynthesis might take place in the outer layers, favoring a delayed detonation model. Interestingly, Si{\sc ii}$\lambda$5972 feature is quite shallow, resulting in an unusually low depth ratio of Si{\sc ii}$\lambda$5972 to $\lambda$6355, $\cal R$(Si{\sc ii}). The low $\cal R$(Si{\sc ii}) is usually interpreted as a high photospheric temperature. However, the weak Si{\sc iii}$\lambda$4560 line suggests a low temperature, in contradiction to the low $\cal R$(Si{\sc ii}). This could imply that the Si{\sc ii}$\lambda$5972 line might be contaminated by underlying emission. We propose that $\cal R$(Si{\sc ii}) may not be a good temperature indicator for rapidly expanding SNe Ia at premaximum phases.Comment: 20 pages, 7 figures, (Received 2008 August 17; Accepted 2009 April 13

Buerger's disease manifesting nodular erythema with livedo reticularis

ArticleINTERNAL MEDICINE. 46(21):1815-1819(2007)journal articl

Rest-Frame R-band Lightcurve of a z~1.3 Supernova Obtained with Keck Laser Adaptive Optics

We present Keck diffraction limited H-band photometry of a z~1.3 Type Ia supernova (SN) candidate, first identified in a Hubble Space Telescope (HST) search for SNe in massive high redshift galaxy clusters. The adaptive optics (AO) data were obtained with the Laser Guide Star facility during four observing runs from September to November 2005. In the analysis of data from the observing run nearest to maximum SN brightness, the SN was found to have a magnitude H=23.9 +/- 0.14 (Vega). We present the H-band (approximately rest-frame R) light curve and provide a detailed analysis of the AO photometric uncertainties. By constraining the aperture correction with a nearby (4" separation) star we achieve 0.14 magnitude photometric precision, despite the spatially varying AO PSF.Comment: 11 pages, 8 figures, Accepted for Publication in AJ Updated the citations, fixed typo

Extensive study of giant magnetoresistance properties in half-metallic Co₂(Fe,Mn)Si-based devices

Fully epitaxial Co₂FexMn1- xSi(CFMS)/Ag/Co₂FexMn1 -xSi current-perpendicular-to-plane giant magnetoresistive devices with various Fe/Mn ratios x and top CFMS layer thicknesses t CFMS were prepared. The highest magnetoresistance (MR) ratios, 58% at room temperature and 184% at 30 K, were observed in the sample with x = 0.4 and tCFMS = 3 nm. Enhancement of interface spin-asymmetry was suggested for x = 0.4 compared with that at x = 0. A MR ratio of 58% was also observed even in a very thin trilayer structure, CFMS(4 nm)/Ag(3 nm)/CFMS(2 nm), which is promising for a next-generation magnetic read sensor for high-density hard disk drives. © 2012 American Institute of Physics.Y. Sakuraba, M. Ueda, Y. Miura, K. Sato, S. Bosu, K. Saito, M. Shirai, T. J. Konno, and K. Takanashi, "Extensive study of giant magnetoresistance properties in half-metallic Co₂(Fe,Mn)Si-based devices", Appl. Phys. Lett. 101, 252408 (2012) https://doi.org/10.1063/1.4772546

Interesting magnetic properties of Fe1−x_{1-x}Cox_xSi alloys

Solid solution between nonmagnetic narrow gap semiconductor FeSi and diamagnetic semi-metal CoSi gives rise to interesting metallic alloys with long-range helical magnetic ordering, for a wide range of intermediate concentration. We report various interesting magnetic properties of these alloys, including low temperature re-entrant spin-glass like behaviour and a novel inverted magnetic hysteresis loop. Role of Dzyaloshinski-Moriya interaction in the magnetic response of these non-centrosymmetric alloys is discussed.Comment: 11 pages and 3 figure