Chistopher Tuplin. Xenophon and Achaemenid Courts: A Survey of Evidence

L’approche de CT est aussi bien documentée mais plus conventionnelle que celle de R. Bichler (c.r. n° 36). L’A. débute par une analyse du vocabulaire ayant trait à l’Empire achéménide dans les œuvres de Xénophon. Il en découle que Xénophon n’a pas de notions précises de l’empire achéménide. Ni les paysages, ni les villes, ni leurs palais ne sont décrits en détail. La vie aulique se base selon lui plus sur l’honneur et la performance que sur l’origine. En tout, l’apport de Xénophon pour une co..

« Das Phantom des Medischen ‘Grossreiches’ und die Behistun-Inschrift », in : E. Dąbrowa, ed., Ancient Iran and its neighbours. Studies in Honour of Prof. Jozef Wolski on Occasion of His 95th Birthday. Krakow, 2005, pp. 11-29. (Electrum 10)

L’A. poursuit sa critique de la réalité d’un empire mède (Abs. Ir. 26, c.r. n° 117). Il résume les arguments : pas d’archives internes ni de capitale, ni de documents archéologiques et d’art. Les sources externes (assyriennes et babyloniennes), par la terminologie qualifiant les Mèdes, n’indiquent pas l’existence d’un État. Il ne reste que le texte d’Hérodote. Puis, R.R. s’appuie sur la fameuse inscription de Behistun dans laquelle l’opposition mède à Darius n’indique nullement une unité réce..

Explicit BCJ Numerators from Pure Spinors

We derive local kinematic numerators for gauge theory tree amplitudes which manifestly satisfy Jacobi identities analogous to color factors. They naturally emerge from the low energy limit of superstring amplitudes computed with the pure spinor formalism. The manifestation of the color--kinematics duality is a consequence of the superstring computation involving no more than (n-2)! kinematic factors for the full color dressed n-point amplitude. The bosonic part of these results describe gluon scattering independent on the number of supersymmetries and captures any N^kMHV helicity configuration after dimensional reduction to D=4 dimensions.Comment: 32 pages, harvma

Six Open String Disk Amplitude in Pure Spinor Superspace

The tree-level amplitude of six massless open strings is computed using the pure spinor formalism. The OPE poles among integrated and unintegrated vertices can be efficiently organized according to the cohomology of pure spinor superspace. The identification and use of these BRST structures and their interplay with the system of equations fulfilled by the generalized Euler integrals allow the full supersymmetric six-point amplitude to be written in compact form. Furthermore, the complete set of extended Bern-Carrasco-Johansson relations are derived from the monodromy properties of the disk world-sheet and explicitly verified for the supersymmetric numerator factors.Comment: 44pp, harvmac; v2: Final version to appear in NP

Large Cyclic Subgroups of Jacobians of Hyperelliptic Curves

In this paper we obtain conditions on the divisors of the group order of the Jacobian of a hyperelliptic genus 2 curve, generated by the complex multiplication method described by Weng (2003) and Gaudry (2005). Examples, where these conditions imply that the Jacobian has a large cyclic subgroup, are given.Comment: 8 pages, 1 figur

The absorption and emission spectrum of the magnetic Herbig Ae star HD 190073

We determine abundances from the absorption spectrum of the magnetic Herbig Ae star HD 190073 (V1295 Aql). The observations are primarily from HARPS spectra obtained at a single epoch. We accept arguments that the presence of numerous emission lines does not vitiate a classical abundance analysis, though it likely reduces the achievable accuracy. Most abundances are closely solar, but several elements show departures of a factor of two to three, as an earlier study has also shown. We present quantitative measurements of more than 60 emission lines, peak intensities, equivalent widths, and FWHM's. The latter range from over 200 km/s (H-alpha, He D3) down to 10--20 km/s (forbidden lines). Metallic emission lines have intermediate widths. We eschew modeling, and content ourselves with a presentation of the observations a successful model must explain. Low-excitation features such as the Na I D-lines and [O I] appear with He I D3, suggesting proximate regions with widely differing Te and Ne as found in the solar chromosphere. The [O I] and [Ca II] lines show sharp, violet-shifted features. Additionally, [Fe II] lines appear to be weakly present in emission.Comment: 7 pages, 10 figures. To appear in Astronomische Nachrichten, Proceedings of the 7th Potsdam Thinkshop on "Magnetic Fields in Stars and Exoplanets.

Coupled-channels analyses for large-angle quasi-elastic scattering in massive systems

We discuss in detail the coupled-channels approach for the large-angle quasi-elastic scattering in massive systems, where many degrees of freedom may be involved in the reaction. We especially investigate the effects of single, double and triple phonon excitations on the quasi-elastic scattering for $^{48}$Ti,$^{54}$Cr,$^{56}$Fe,$^{64}$Ni and $^{70}$Zn$+^{208}$Pb systems, for which the experimental cross sections have been measured recently. We show that the present coupled-channels calculations well account for the overall width of the experimental barrier distribution for these systems. In particular, it is shown that the calculations taking into account single quadrupole phonon excitations in $^{48}$Ti and triple octupole phonon excitations in $^{208}$Pb reasonably well reproduce the experimental quasi-elastic cross section and barrier distribution for the $^{48}$Ti$+^{208}$Pb reaction. On the other hand, $^{54}$Cr,$^{56}$Fe,$^{64}$Ni and $^{70}$Zn$+^{208}$Pb systems seem to require the double quadrupole phonon excitations in the projectiles in order to reproduce the experimental data.Comment: 11 pages, 6 figure