Dp-branes, NS5-branes and U-duality from nonabelian (2,0) theory with Lie 3-algebra

We derive the super Yang-Mills action of Dp-branes on a torus T^{p-4} from the nonabelian (2,0) theory with Lie 3-algebra. Our realization is based on Lie 3-algebra with pairs of Lorentzian metric generators. The resultant theory then has negative norm modes, but it results in a unitary theory by setting VEV's of these modes. This procedure corresponds to the torus compactification, therefore by taking a transformation which is equivalent to T-duality, the Dp-brane action is obtained. We also study type IIA/IIB NS5-brane and Kaluza-Klein monopole systems by taking other VEV assignments. Such various compactifications can be realized in the nonabelian (2,0) theory, since both longitudinal and transverse directions can be compactified, which is different from the BLG theory. We finally discuss U-duality among these branes, and show that most of the moduli parameters in U-duality group are recovered. Especially in D5-brane case, the whole U-duality relation is properly reproduced.Comment: 1+26 page

Effective interaction for pf-shell nuclei

An effective interaction is derived for use in the full pf basis. Starting from a realistic G-matrix interaction, 195 two-body matrix elements and 4 single-particle energies are determined by fitting to 699 energy data in the mass range 47 to 66. The derived interaction successfully describes various structures of pf-shell nuclei. As examples, systematics of the energies of the first 2+ states in the Ca, Ti, Cr, Fe, and Ni isotope chains and energy levels of 56,57,58Ni are presented. The appearance of a new magic number 34 is seen.Comment: 5 pages, 4 figures, to be published in Phys. Rev.

X-ray and Radio Follow-up Observations of High-Redshift Blazar Candidates in the Fermi-LAT Unassociated Source Population

We report on the results of X-ray and radio follow-up observations of two GeV gamma-ray sources 2FGL J0923.5+1508 and 2FGL J1502.1+5548, selected as candidates for high-redshift blazars from unassociated sources in the {\it Fermi} Large Area Telescope Second Source Catalog. We utilize the Suzaku satellite and the VLBI Exploration of Radio Astrometry (VERA) telescopes for X-ray and radio observations, respectively. For 2FGL J0923.5+1508, a possible radio counterpart NVSS J092357+150518 is found at 1.4 GHz from an existing catalog, but we do not detect any X-ray emission from it and derive a flux upper limit $F_{\rm 2-8 keV} <$ 1.37 $\times$ 10$^{-14}$ erg cm$^{-2}$ s$^{-1}$. Radio observations at 6.7 GHz also result in an upper limit of $S_{\rm 6.7 GHz}$ $<$ 19 mJy, implying a steep radio spectrum that is not expected for a blazar. On the other hand, we detect X-rays from NVSS J150229+555204, the potential 1.4 GHz radio counterpart of 2FGL J1502.1+5548. The X-ray spectrum can be fitted with an absorbed power-law model with a photon index $\gamma$=1.8$^{+0.3}_{-0.2}$ and the unabsorbed flux is $F_{\rm 2-8 keV}$=4.3$^{+1.1}_{-1.0}$ $\times$ 10$^{-14}$ erg cm$^{-2}$ s$^{-1}$. Moreover, we detect unresolved radio emission at 6.7 GHz with flux $S_{\rm 6.7 GHz}$=30.1 mJy, indicating a compact, flat-spectrum radio source. If NVSS J150229+555204 is indeed associated with 2FGL J1502.1+5548, we find that its multiwavelength spectrum is consistent with a blazar at redshift $z \sim 3-4$.Comment: 24 pages, 7 figures, 6 tables, accepted for publication in Ap

Rotation Curves of Galaxies by Fourth Order Gravity

We investigate the radial behavior of galactic rotation curves by a Fourth Order Gravity adding also the Dark Matter component. The Fourth Order Gravity is a Lagrangian containing the Ricci scalar, the Ricci and Riemann tensor, but the rotation curves are depending only on two free parameters. A systematic analysis of rotation curves, in the Newtonian Limit of theory, induced by all galactic sub-structures of ordinary matter is shown. This analysis is presented for Fourth Order Gravity with and without Dark Matter. The outcomes are compared with respect to classical outcomes of General Relativity. The gravitational potential of point-like mass is the usual potential corrected by two Yukawa terms. The rotation curve is higher or also lower than curve of General Relativity if in the Lagrangian the Ricci scalar square is dominant or not with respect to the contribution of the Ricci tensor square. The curves are compared with the experimental data for the Milky Way and the galaxy NGC 3198. Although the Fourth Order Gravity gives more rotational contributions, in the limit of large distances the Keplerian behavior is present, and it is missing if we add a Dark Matter component. By modifying the theory of Gravitation consequently also the spatial description of Dark Matter could undergo a modification. At last we compare the gravitational potential by Fourth Order Gravity with respect to more used potential induced by power law of Ricci scalar.Comment: 14 pages, 10 figure

Rotating and infalling motion around the high-mass young stellar object Cepheus A-HW2 observed with the methanol maser at 6.7 GHz

We have measured the internal proper motions of the 6.7 GHz methanol masers associated with Cepheus A (Cep A) HW2 using Very Long Baseline Interferometery (VLBI) observations. We conducted three epochs of VLBI monitoring observations of the 6.7 GHz methanol masers in Cep A-HW2 with the Japanese VLBI Network (JVN) over the period between 2006-2008. In 2006, we were able to use phase-referencing to measure the absolute coordinates of the maser emission with an accuracy of a few milliarcseconds. We compared the maser distribution with other molecular line observations that trace the rotating disk. We measured the internal proper motions for 29 methanol maser spots, of which 19 were identified at all three epochs and the remaining ten at only two epochs. The magnitude of proper motions ranged from 0.2 to 7.4 km/s, with an average of 3.1 km/s. Although there are large uncertainties in the observed internal proper motions of the methanol maser spots in Cep A, they are well fitted by a disk that includes both rotation and infall velocity components. The derived rotation and infall velocities at the disk radius of 680 au are 0.5 +- 0.7 and 1.8 +- 0.7 km/s, respectively. Assuming that the modeled disk motion accurately represents the accretion disk around the Cep A-HW2 high-mass YSO, we estimated the mass infall rate to be 3 x 10^{-4} n_8 Msun/yr (n_8 is the gas volume density in units of 10^{8} cm^{-3}). The combination of the estimated mass infall rate and the magnitude of the fitted infall velocity suggests that Cep A-HW2 is at an evolutionary phase of active gas accretion from the disk onto the central high-mass YSO. The infall momentum rate is estimated to be 5 x 10^{-4} n_8 Msun/yr km/s, which is larger than the estimated stellar radiation pressure of the HW2 object, supporting the hypothesis that this object is in an active gas accretion phase.Comment: 16 pages, 6 figures, 5 tables, accepted for publication in Astronomy & Astrophysic

Spectrum of Optically Thin Advection Dominated Accretion Flow around a Black Hole: Application to Sgr A*

The global structure of optically thin advection dominated accretion flows which are composed of two-temperature plasma around black holes is calculated. We adopt the full set of basic equations including the advective energy transport in the energy equation for the electrons. The spectra emitted by the optically thin accretion flows are also investigated. The radiation mechanisms which are taken into accout are bremsstrahlung, synchrotron emission, and Comptonization. The calculation of the spectra and that of the structure of the accretion flows are made to be completely consistent by calculating the radiative cooling rate at each radius. As a result of the advection domination for the ions, the heat transport from the ions to the electrons becomes practically zero and the radiative cooling balances with the advective heating in the energy equation of the electrons. Following up on the successful work of Narayan et al. (1995), we applied our model to the spectrum of Sgr A*. We find that the spectrum of Sgr A* is explained by the optically thin advection dominated accretion flow around a black hole of the mass M_bh=10^6 M_sun. The parameter dependence of the spectrum and the structure of the accretion flows is also discussed.Comment: AAS LaTeX file; 26 pages; 12 ps figures; to be published in ApJ. PDF files are obtainable via following anonymous ftp. ftp://ftp.kusastro.kyoto-u.ac.jp/pub/manmoto/preprint/spec_sgrA.tar.g

Improved Power Handling Capability of Superconducting Microstrip Lines for Microwave Devices

AbstractWe examined a microstrip line structure to reduce the current concentration at the outer edge of a microstrip line. We developed three kinds of microstrip line; sliced-microstrip line, layered-film microstrip line, and conventional microstrip line. The first microstrip line is a line divided into the narrow line, and the second one is a line made by a layered thin film. Electromagnetic simulations indicated that the current concentration of the outer edge of the sliced microstrip line and layered film microstrip line was lower than that of a conventional microstrip line. We measured the power handling capability of the filters made by sliced-microstrip lines, layered-film microstrip lines, and conventional microstrip lines. The value of the first and the second filters was better than that of a conventional one. The difference in the characteristics is based on the difference in the current concentration at the outer edge of the microstrip lines

Large scale shell model calculations for odd-odd 58−62^{58-62}Mn isotopes

Large scale shell model calculations have been carried out for odd-odd $^{58-62}$Mn isotopes in two different model spaces. First set of calculations have been carried out in full $\it{fp}$ shell valence space with two recently derived $\it{fp}$ shell interactions namely GXPF1A and KB3G treating $^{40}$Ca as core. The second set of calculations have been performed in ${fpg_{9/2}}$ valence space with the $fpg$ interaction treating $^{48}$Ca as core and imposing a truncation by allowing up to a total of six particle excitations from the 0f$_{7/2}$ orbital to the upper $\it{fp}$ orbitals for protons and from the upper $\it{fp}$ orbitals to the 0g$_{9/2}$ orbital for neutron. For low-lying states in $^{58}$Mn, the KB3G and GXPF1A both predicts good results and for $^{60}$Mn, KB3G is much better than GXPF1A. For negative parity and high-spin positive parity states in both isotopes $fpg$ interaction is required. Experimental data on $^{62}$Mn is sparse and therefore it is not possible to make any definite conclusions. More experimental data on negative parity states is needed to ascertain the importance of 0g$_{9/2}$ and higher orbitals in neutron rich Mn isotopes.Comment: 5 pages, 4 figures, Submitted to Eur. Phys. J.