We compare our calculations of the frequencies of the fundamental g-, c-, and p-modes of relativistic thin accretion disks with recent observations of high-frequency quasi-periodic oscillations (QPOs) in X-ray binaries with black hole candidates. These classes of modes encompass all adiabatic perturbations of such disks. The frequencies of these modes depend mainly on the mass and angular momentum of the black hole; their weak dependence on disk luminosity is also explicitly indicated. Identifying the recently discovered, relatively stable QPO pairs with the fundamental g-and c-modes provides a determination of the mass and angular momentum of the black hole. For GRO J1655Ϫ40, and , in agreement with spectroscopic mass

We Ðrst brieÑy review how we investigate the modes of oscillation trapped within the inner region of accretion disks by the strong-Ðeld gravitational properties of a black hole (or a compact, weakly magnetized neutron star). Then we focus on the "" corrugation ÏÏ (c-) modes, nearly incompressible perturbations of the inner disk. The fundamental c-modes have eigenfrequencies (ordered by radial mode number) which correspond to the Lense-Thirring frequency, evaluated at the outer trapping radius of the mode, in the slow rotation limit. This trapping radius is a decreasing function of the black hole angular momentum, so a signiÐcant portion of the disk is modulated only for slowly rotating black holes. The eigenfrequencies are thus strongly increasing functions of black hole angular momentum. The dependence of the eigenfrequencies on the speed of sound (or the luminosity) within the disk is very weak, except for slowly rotating black holes.

The anomalous behavior of the spin-spin correlation at large momentum transfer in p p elastic scattering is described in terms of the degrees of freedom associated with the onset of the charm threshold. A non-perturbative analysis based on the symmetries of QCD is used to extract the relevant dynamics of the charmonium-proton interaction. The enhancement to p p amplitudes and their phase follow from analyticity and unitarity, giving a plausible explanation of the spin anomaly. The interaction between cc and light quarks in nuclei may form a distinct kind of nuclear matter, nuclear bound quarkonium.

We extend our investigation of the normal modes of small adiabatic oscillations of relativistic barotropic thin accretion disks to the inertial-pressure (p) modes. We focus here on the lowest frequency fundamental p-modes, those with no axial or vertical nodes in their distribution. Through a variety of analyses, we obtain closed-form expressions for the eigenfrequencies and eigenfunctions. These depend on the luminosity and viscosity parameter of the disk as well as the mass and angular momentum of the black hole via detailed formulae for the speed of sound. The e †ect of a torque on the inner edge of the disk is also included. We compare the p-mode properties to those of the g-and c-modes.

The perturbations of weakly-viscous, barotropic, non-self-gravitating, Newtonian rotating fluids are analyzed via a single partial differential equation. The results are then used to find an expression for the viscosity-induced normal-mode complex eigenfrequency shift, with respect to the case of adiabatic perturbations. However, the effects of viscosity are assumed to have been incorporated in the unperturbed (equilibrium) model. This paper is an extension of the normal-mode formalism developed by Ipser & Lindblom for adiabatic pulsations of purely-rotating perfect fluids. The formulas derived are readily applicable to the perturbations of thin and thick accretion disks. We provide explicit expressions for thin disks, employing results from previous relativistic analyses of adiabatic normal modes of oscillation. In this case, we find that viscosity causes the fundamental p- and g- modes to grow while the fundamental c-mode could have either sign of the damping rate.Comment: Accepted for publication by The Astrophysical Journal. 11 pages, no figure