Raman Scattering in Cuprate Superconductors

A theory for electronic Raman scattering in the cuprate superconductors is presented with a specific emphasis on the polarization dependence of the spectra which can infer the symmetry of the energy gap. Signatures of the effects of disorder on the low frequency and low temperature behavior of the Raman spectra for different symmetry channels provide detailed information about the magnitude and the phase of the energy gap. Properties of the theory for finite T are discussed and compared to recent data concerning the doping dependence of the Raman spectra in cuprate superconductors, and remaining questions are addressed.Comment: 27 pages, 11 figures, style file include

Resolving the molecular gas around the lensed quasar RXJ0911.4+0551

We report on high angular resolution observations of the CO(7-6) line and millimeter continuum in the host galaxy of the gravitationally lensed (z~2.8) quasar RXJ0911.4+0551 using the Plateau de Bure Interferometer. Our CO observations resolve the molecular disk of the source. Using a lens model based on HST observations we fit source models to the observed visibilities. We estimate a molecular disk radius of 1$\pm$0.2 kpc and an inclination of 69$\pm$6\deg, the continuum is more compact and is only marginally resolved by our observations. The relatively low molecular gas mass, $Mgas=(2.3\pm 0.5)\times 10^{9}$ Msolar, and far infrared luminosity, $LFIR=(7.2\pm 1.5) \times 10^{11}$ Lsolar, of this quasar could be explained by its relatively low dynamical mass, $Mdyn=(3.9\pm 0.9)\times 10^9$ Msolar. It would be a scaled-down version the QSOs usually found at high-z. The FIR and CO luminosities lie on the correlation found for QSOs from low to high redshifts and the gas-to-dust ratio ($45\pm 17$) is similar to the one measured in the z=6.4 QSO, SDSS J1148+5251. Differential magnification affects the continuum-to-line luminosity ratio, the line profile and possibly the spectral energy distribution.Comment: Accepted for publication in A&A, revised after language editin

Isovector Channel Role of Relativistic Mean Field Models in the Neutrino Mean Free Path

An improvement in the treatment of the isovector channel of relativistic mean field (RMF) models based on effective field theory (E-RMF) is suggested, by adding an isovector scalar (delta) meson and using a similar procedure to the one used by Horowitz and Piekarewicz to adjust the isovector-vector channel in order to achieve a softer density dependent symmetry energy of the nuclear matter at high density. Their effects on the equation of state (EOS) at high density and on the neutrino mean free path (NMFP) in neutron stars are discussed.Comment: 20 pages, 8 figure

Two-boson Correlations in Various One-dimensional Traps

A one-dimensional system of two trapped bosons which interact through a contact potential is studied using the optimized configuration interaction method. The rapid convergence of the method is demonstrated for trapping potentials of convex and non-convex shapes. The energy spectra, as well as natural orbitals and their occupation numbers are determined in function of the inter-boson interaction strength. Entanglement characteristics are discussed in dependence on the shape of the confining potential.Comment: 5 pages, 3 figure

CPA for charge ordering in the extended Hubbard model

We study charge ordering in the extended Hubbard model with both on-site and nearest neighbor Coulomb repulsion (U and V, respectively) within the Coherent potential approximation (CPA). The phase boundary between the homogeneous and charge ordered phase for the square lattice is obtained for different values of U. It is shown that at quarter filling for all values of U the charge ordering exists only if the inter-site Coulomb repulsion V exceeds certain critical value which is of the order of the kinetic energy t. At finite temperature a reentrant transition is found in some region of V.Comment: 5 pages, 4 figure

Dual frequency VSOP imaging of the jet in S5 0836+710

The luminous high-redshift (z=2.17) quasar S50836+710 has been observed in October 1997 with the VSOP at 1.6 GHz and 5 GHz. We report here a previously unpublished image made from the data at 1.6 GHz and compare the structure of a relativistic jet in this quasazr at the two frequencies. We present a spectral index image tracing spectral properties of the jet up to ~40 milliarcsecond distance from the nucleus. The curved jet ridge line observed in the images and the spectral index distribution can be described by Kelvin-Helmholtz instability developing in a relativistic outflow with a Mach number of ~6. In this description, the overall ridge line of the jet is formed by the helical surface mode of Kelvin-Helmholtz instability, while areas of flatter spectral index embedded into the flow correspond to pressure enhancements produced by the elliptical surface mode of the instability. An alternative explanation involving a sequence of slowly dissipating shocks cannot be ruled out at this point.Comment: 7 pages, 4 figures, pasj00.cls. Submitted to PASJ. (Corrected figure orientation