Collision of spinning black holes in the close limit

In this paper we consider the collision of spinning holes using first order perturbation theory of black holes (Teukolsky formalism). With these results (along with ones, we published in the past) one can predict the properties of the gravitational waves radiated from the late stage inspiral of two spinning, equal mass black holes. Also we note that the energy radiated by the head-on collision of two spinning holes with spins (that are equal and opposite) aligned along the common axis is more than the case in which the spins are perpendicular to the axis of the collision.Comment: 6 pages, 3 figures, submitted to PR

Accurate time-domain gravitational waveforms for extreme-mass-ratio binaries

The accuracy of time-domain solutions of the inhomogeneous Teukolsky equation is improved significantly. Comparing energy fluxes in gravitational waves with highly accurate frequency-domain results for circular equatorial orbits in Schwarzschild and Kerr, we find agreement to within 1% or better, which we believe can be even further improved. We apply our method to orbits for which frequency-domain calculations have a relative disadvantage, specifically high-eccentricity (elliptical and parabolic) "zoom-whirl" orbits, and find the energy fluxes, waveforms, and characteristic strain in gravitational waves.Comment: 6 pages, 9 figures, 2 tables; Changes: some errors corrected. Comparison with Frequency-domain now done in stronger fiel

Late-time Kerr tails: generic and non-generic initial data sets, "up" modes, and superposition

Three interrelated questions concerning Kerr spacetime late-time scalar-field tails are considered numerically, specifically the evolutions of generic and non-generic initial data sets, the excitation of "up" modes, and the resolution of an apparent paradox related to the superposition principle. We propose to generalize the Barack-Ori formula for the decay rate of any tail multipole given a generic initial data set, to the contribution of any initial multipole mode. Our proposal leads to a much simpler expression for the late-time power law index. Specifically, we propose that the late-time decay rate of the $Y_{\ell m}$ spherical harmonic multipole moment because of an initial $Y_{\ell' m}$ multipole is independent of the azimuthal number $m$, and is given by $t^{-n}$, where $n=\ell'+\ell+1$ for $\ell<\ell'$ and $n=\ell'+\ell+3$ for $\ell\ge\ell'$. We also show explicitly that the angular symmetry group of a multipole does not determine its late-time decay rate.Comment: 12 pages, 13 figures, 4 tables. Substantially revised manuscrip

Landau Ginzburg Theory and Nuclear Matter at Finite Temperature

Based on recent studies of the temperature dependence of the energy and specific heat of liquid nuclear matter, a phase transition is suggested at a temperature $\sim .8$ MeV. We apply Landau Ginzburg theory to this transition and determine the behaviour of the energy and specific heat close to the critical temperature in the condensed phase.Comment: 10 pages, Revte

Limits to Policy Reversal: Privatization in India

We examine the effect of regime change on privatization using the 2004 election surprise in India. In that election, the pro-reform BJP was un-expectedly defeated by a less reformist coalition. Government controlled companies that were being studied for complete privatization by the BJP dropped by 7.5 percent relative to private firms. By contrast, government controlled firms that were not being considered for privatization, or firms that had already been fully privatized firms, did not experience significant drop relative to private firms. Firms that the BJP had slated for definite future privatization experienced intermediate declines of approximately 3.5 percent. We interpret this as evidence consistent with investor belief of policy irreversibility in privatization, where reforms may reach a 'point of no return' beyond which future regimes have difficulty reversing those policies. Taking advantage of an 'intermediate' event where policies were expected to be more heavily influenced by the communist party, we still find evidence consistent with policy irreversibility.

Testing Limits to Policy Reversal: Evidence from Indian Privatizations

We examine the effect of regime change on privatization using the 2004 election surprise in India. The pro-reform BJP was unexpectedly defeated by a less reformist coalition. Stock prices of government-controlled companies that had been slated for definite privatization by the BJP dropped by 3.5 percent relative to private firms. Surprisingly, government-controlled companies that were only under study for possible privatization fell by 7.5 percent relative to private firms. We interpret this as evidence of investor belief of policy irreversibility, where reforms may reach a stage beyond which future regimes have difficulty reversing those policies. Further analysis suggests that layoffs, combined with the privatization announcement, served as a credible commitment to the government's privatization agenda.

The collision of two slowly rotating, initially non boosted, black holes in the close limit

We study the collision of two slowly rotating, initially non boosted, black holes in the close limit. A ``punctures'' modification of the Bowen - York method is used to construct conformally flat initial data appropriate to the problem. We keep only the lowest nontrivial orders capable of giving rise to radiation of both gravitational energy and angular momentum. We show that even with these simplifications an extension to higher orders of the linear Regge-Wheeler-Zerilli black hole perturbation theory, is required to deal with the evolution equations of the leading contributing multipoles. This extension is derived, together with appropriate extensions of the Regge-Wheeler and Zerilli equations. The data is numerically evolved using these equations, to obtain the asymptotic gravitational wave forms and amplitudes. Expressions for the radiated gravitational energy and angular momentum are derived and used together with the results of the numerical evolution to provide quantitative expressions for the relative contribution of different terms, and their significance is analyzed.Comment: revtex, 18 pages, 2 figures. Misprints corrected. To be published in Phys. Rev.