We study numerically the fully nonlinear spherically-symmetric collapse of a selfgravitating, minimally-coupled, massless scalar field. Our numerical code is based on double-null coordinates and on free evolution of the metric functions and the scalar field. The numerical code is stable and second-order accurate. We use this code to study the late-time asymptotic behavior at fixed r (outside th...

I examine the pair creation of black holes in spacetimes with a cosmological constant of either sign. I consider cosmological C-metrics and show that the conical singularities in this metric vanish only for three distinct classes of black hole metric, two of which have compact event horizons on each spatial slice. One class is a generalization of the Reissner-Nordstrom (anti) de Sitter black ho...

Electron-hole excitations in the surface bands of GaAs (110) are analyzed using constrained density-functional theory calculations. The results show that Frenkel-type autolocalized excitons are formed. The excitons induce a local surface unrelaxation which results in a strong exciton-exciton attraction and makes complexes of two or three electron-hole pairs more favorable than separate excitons...

We study global vortices coupled to (2+1) dimensional gravity with negative cosmological constant. We found nonsingular vortex solutions in φ-theory with a broken U(1) symmetry, of which the spacetimes do not involve physical curvature singularity. When the magnitude of negative cosmological constant is larger than a critical value at a given symmetry breaking scale, the spacetime structure is ...

The entropy of a seven dimensional Schwarzschild black hole of arbitrary large radius is obtained by a mapping onto a near extremal self-dual three-brane whose partition function can be evaluated. The three-brane arises from duality after submitting a neutral blackbrane, from which the Schwarzschild black hole can be obtained by compactification, to an infinite boost in non compact eleven dimen...

In this paper, genus statistics have been applied to an HI column density map of the Small Magellanic Cloud in order to study its topology. At the smallest scales studied (26 pc ≤ λ ≤ 75 pc) the genus shift is negative, implying a clump topology. At medium scales (75 pc ≤ λ ≤ 125 pc) the topology shifts to a neutral/slightly positive value, indicating a tendency towards a swiss-cheese/hole topo...

Doubtlessly the most central notion in superconductivity, for both low and high transition temperatures Tc, is that of Cooper pairs (CPs) [1] that form among the underlying electron (or hole) charge carriers of the many-electron system. And yet, it is perhaps the least understood concept. Shortly after the publication of the BCS theory [2] of superconductivity, charged pairs observed in magneti...

We present soft X-ray spectroscopy of the black hole binary LMC X-3 from the XMM-Newton Reflection Grating Spectrometer. The observations span the full range of spectral states seen in LMC X-3. The spectra are completely dominated by continuum emission, and the neutral absorbing column measured from the O I edge (N H = 3.8 +0.8 −0.7 × 10 20 cm −2) is consistent with the Galactic interstellar co...

GaSb inversion-mode PMOSFETs with atomiclayer-deposited (ALD) Al2O3 as gate dielectric are demonstrated. A 0.75-μm-gate-length device has a maximum drain current of 70 mA/mm, a transconductance of 26 mS/mm, and a hole inversion mobility of 200 cm/V · s. The OFF-state performance is improved by reducing the ALD growth temperature from 300 ◦C to 200 ◦C. The measured interface trap distribution sh...