CO(J=6-5) Observations of the Quasar SDSS1044-0125 at z = 5.8

We present a result of the quasar CO(J=6-5) observations of SDSSp J104433.04-012502.2 at z = 5.8. Ten-days observations with the Nobeyama Millimeter Array yielded an rms noise level of ~ 2.1 mJy/beam in a frequency range from 101.28 GHz to 101.99 GHz at a velocity resolution of 120 km/s. No significant clear emission line was detected in the observed field and frequency range. Three sigma upper limit on the CO(J=6-5) luminosity of the object is 2.8 x 10^10 K km/s pc^2, corresponding to a molecular gas mass of 1.2 x 10^11 Solar Mass, if a conversion factor of 4.5 Solar Mass /(K km/s pc^2) is adopted. The obtained upper limit on CO luminosity is slightly smaller than those observed in quasars at z=4-5 toward which CO emissions are detected.Comment: 4 pages, 3 figures, LaTeX2e, to appear in Publication of Astronomical Society of Japan (PASJ), Postscript file available at ftp://ftp.kusastro.kyoto-u.ac.jp/pub/iwata/preprint/sdss1044/sdss.ps.g

Solving the Bethe-Salpeter equation for bound states of scalar theories in Minkowski space

We apply the perturbation theory integral representation (PTIR) to solve for the bound state Bethe-Salpeter (BS) vertex for an arbitrary scattering kernel, without the need for any Wick rotation. The results derived are applicable to any scalar field theory (without derivative coupling). It is shown that solving directly for the BS vertex, rather than the BS amplitude, has several major advantages, notably its relative simplicity and superior numerical accuracy. In order to illustrate the generality of the approach we obtain numerical solutions using this formalism for a number of scattering kernels, including cases where the Wick rotation is not possible.Comment: 28 pages of LaTeX, uses psfig.sty with 5 figures. Also available via WWW at http://www.physics.adelaide.edu.au/theory/papers/ADP-97-10.T248-abs.html or via anonymous ftp at ftp://bragg.physics.adelaide.edu.au/pub/theory/ADP-97-10.T248.ps A number of (crucial) typographical errors in Appendix C corrected. To be published in Phys. Rev. D, October 199

Photoionized gas in hydrostatic equilibrium: the role of gravity

We present a method to include the effects of gravity in the plasma physics code Cloudy. More precisely, a term is added to the desired gas pressure in order to enforce hydrostatic equilibrium, accounting for both the self-gravity of the gas and the presence of an optional external potential. As a test case, a plane-parallel model of the vertical structure of the Milky Way disk near the solar neighbourhood is considered. It is shown that the gravitational force determines the scale height of the disk, and it plays a critical role in setting its overall chemical composition. However, other variables, such as the shape of incident continuum and the intensity of the Galactic magnetic field, strongly affect the predicted structure.Comment: 9 pages, 8 figures, MNRAS in pres

Is Environmental Tax Effective for Total Emission of Carbon Dioxide?

This paper deals with how to analyze the effectiveness of environmental tax (carbon tax) for controlling the total emission of carbon dioxide. The problem is formulated by using Leontief-type input-output model which represents a national environmental-economic model, where the environmental tax paid for emission of untreated carbon dioxide is included in the model. A numerical example based on the inter-industry table obtained in 1985, is included

Asymptotic Expansions of Feynman Amplitudes in a Generic Covariant Gauge

We show in this paper how to construct Symanzik polynomials and the Schwinger parametric representation of Feynman amplitudes for gauge theories in an unspecified covariant gauge. The complete Mellin representation of such amplitudes is then established in terms of invariants (squared sums of external momenta and squared masses). From the scaling of the invariants by a parameter we extend for the present situation a theorem on asymptotic expansions, previously proven for the case of scalar field theories, valid for both ultraviolet and infrared behaviors of Feynman amplitudes.Comment: 10 pages, revtex, no figure

Anisotropy and shear-velocity heterogeneities in the upper mantle

Long-period surface waves are used to map lateral heterogeneities of velocity and anisotropy in the upper mantle. The dispersion curves are expanded in spherical harmonics up to degree 6 and inverted to find the depth structure. The data are corrected for the effect of surface layers and both Love and Rayleigh waves are used. Shear wave velocity and shear polarization anisotropy can be resolved down to a depth of about 450 km. The shear wave velocity distribution to 200 km depth correlates with surface tectonics, except in a few anomalous regions. Below that depth the correlation vanishes. Cold subducted material shows up weakly at 350 km as fast S-wave anomalies. In the transition region a large scale pattern appears with fast mantle in the South-Atlantic. S-anisotropy at 200 km can resolve uprising or downwelling currents under some ridges and subduction zones. The Pacific shows a NW-SE fabric

The running coupling from the four-gluon vertex in Landau gauge Yang-Mills theory

We consider the running coupling from the four-gluon vertex in Landau gauge, SU($N_c$) Yang-Mills theory as given by a combination of dressing functions of the vertex and the gluon propagator. We determine these functions numerically from a coupled set of Dyson-Schwinger equations. We reproduce asymptotic freedom in the ultraviolet momentum region and find a coupling of order one at mid-momenta. In the infrared we find a nontrivial (i.e. nonzero) fixed point which is three orders of magnitude smaller than the corresponding fixed point in the coupling of the ghost-gluon vertex. This result explains why the Dyson-Schwinger and the functional renormalization group equations for the two point functions can agree in the infrared, although their structure is quite different. Our findings also support Zwanziger's notion of an infrared effective theory driven by the Faddeev-Popov determinant.Comment: 25 pages, 4 figures; v2: minor clarifications added and typos corrected, version accepted by PR

Perturbative QCD of hard and soft processes

We discuss some problems concerning the application of perturbative QCD to high energy processes. In particular for hard processes, we analyze higher order and higher twist corrections. It is argued that these effects are of great importance for understanding the behaviour of pion electromagnetic form factor at moderately large momentum transfers. For soft processes, we show that summing the contributions of the lowest twist operators leads to a Regge-like amplitude.Comment: Reproduction of unpublished JINR Report E2-80-521, Dubna 1980. 22 pages 9 figures. To be published in Modern Physics Letters A. Style file is include

In-medium Yang-Mills equations: a derivation and canonical quantization

The equations for Yang-Mills field in a medium are derived in a linear approximation with respect to the gauge coupling parameter and the external field. The obtained equations closely resemble the macroscopic Maxwell equations. A canonical quantization is performed for a family of Fermi-like gauges in the case of constant and diagonal (in the group indices) tensors of electric permittivity and magnetic permeability. The physical subspace is defined and the gauge field propagator is evaluated for a particular choice of the gauge. The propagator is applied for evaluation of the cross-section of ellastic quark scattering in the Born approximation. Possible applications to Cherenkov-type gluon radiation are commented briefly.Comment: 27 pages, references added, version extended with emphasis on non-Abelian gauge group impact on medium characteristics. To appear in J. Phys.