All electro--vacuum Majumdar--Papapetrou space--times with nonsingular black holes

We show that all Majumdar--Papapetrou electrovacuum space--times with a non--empty black hole region and with a non--singular domain of outer communications are the standard Majumdar--Papapetrou space--times.Comment: 9 pages, Late

The classification of static vacuum space-times containing an asymptotically flat spacelike hypersurface with compact interior

We prove non-existence of static, vacuum, appropriately regular, asymptotically flat black hole space-times with degenerate (not necessarily connected) components of the event horizon. This finishes the classification of static, vacuum, asymptotically flat domains of outer communication in an appropriate class of space-times, showing that the domains of outer communication of the Schwarzschild black holes exhaust the space of appropriately regular black hole exteriors.Comment: This version includes an addendum with a corrected proof of non-existence of zeros of the Killing vector at degenerate horizons. A problem with yet another Lemma is pointed out; this problem does not arise if one assumes analyticity of the metric. An alternative solution, that does not require analyticity, has been given in arXiv:1004.0513 [gr-qc] under appropriate global condition

On the topology of stationary black holes

We prove that the domain of outer communication of a stationary, globally hyperbolic spacetime satisfying the null energy condition must be simply connected. Under suitable additional hypotheses, this implies, in particular, that each connected component of a cross-section of the event horizon of a stationary black hole must have spherical topology.Comment: 7 pages, Late

Towards a classification of static electro-vacuum space-times containing an asymptotically flat spacelike hypersurface with compact interior

We show that static electro-vacuum black hole space-times containing an asymptotically flat spacelike hypersurface with compact interior and with both degenerate and non-degenerate components of the event horizon do not exist, under the supplementary hypothesis that all degenerate components of the event horizon have charges of the same sign. This extends previous uniqueness theorems of Simon and Masood-ul-Alam (where only non-degenerate horizons were allowed) and Heusler (where only degenerate horizons were allowed).Comment: Reverted to original v1; v2 was a result of a manipulation error, and was meant to be an update to gr-qc/9809088. The problems adressed in the addendum in v2 of gr-qc/9809088 apply also to this paper, and are similarly taken care of by the addendum to gr-qc/9809088, and by the analysis in arXiv:1004.0513 [gr-qc

Untangling the Interconnected Relationships between Alcohol Use, Employment, and Offending

Both substance use and employment are correlates of crime that are heavily examined by criminological research. Efforts to explore these connections have produced two rich bodies of literature that provide insight into the nuances of the relationship between substance use and offending and the relationship between employment and crime. Research shows that while substance use increases subsequent criminal behavior, employment seems to reduce offending. Given the strong positive association between substance use and crime and the inverse effect of employment on offending, it is possible that drug use and employment interact in their impact on crime. In addition to potential moderation, the relationship between drug use, employment, and crime may be explained by mediation mechanisms. Thus, the current study uses data from the 1997 National Longitudinal Survey of Youth (NLSY97) to examine the possibility of moderation and/or mediation between substance use and employment in their impact on offending

Boundary regularity of conformally compact Einstein metrics

We show that C^2 conformally compact Riemannian Einstein metrics have conformal compactifications that are smooth up to the boundary in dimension 3 and all even dimensions, and polyhomogeneous in odd dimensions greater than 3.Comment: Latex2e, 25 pages. This is the final version accepted for publication in the Journal of Differential Geometr

On completeness of orbits of Killing vector fields

A Theorem is proved which reduces the problem of completeness of orbits of Killing vector fields in maximal globally hyperbolic, say vacuum, space--times to some properties of the orbits near the Cauchy surface. In particular it is shown that all Killing orbits are complete in maximal developements of asymptotically flat Cauchy data, or of Cauchy data prescribed on a compact manifold. This result gives a significant strengthening of the uniqueness theorems for black holes.Comment: 16 pages, Latex, preprint NSF-ITP-93-4

On the uniqueness of smooth, stationary black holes in vacuum

We prove a conditional "no hair" theorem for smooth manifolds: if $E$ is the domain of outer communication of a smooth, regular, stationary Einstein vacuum, and if a technical condition relating the Ernst potential and Killing scalar is satisfied on the bifurcate sphere, then $E$ is locally isometric to the domain of outer communication of a Kerr space-time.Comment: Various correction

Stationary black holes: Uniqueness and beyond

WOS:000304855500001 (Nº de Acesso Web of Science)“Prémio Científico ISCTE-IUL 2013”The spectrum of known black-hole solutions to the stationary Einstein equations has been steadily increasing, sometimes in unexpected ways. In particular, it has turned out that not all black-hole-equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro-vacuum black-hole spacetimes ceases to exist in self-gravitating non-linear field theories. This text aims to review some developments in the subject and to discuss them in light of the uniqueness theorem for the Einstein-Maxwell system

mRNA and protein expression of FGF-1, FGF-2 and their receptors in the porcine umbilical cord during pregnancy.

The fibroblast growth factors (FGFs) are multifunctional proteins that, among other roles, regulate structural reorganization of uterine and placental vascular bed during pregnancy. Thus, we analyzed mRNA and protein expression and immunohistochemical localization of FGF-1 and FGF-2, and their receptors (FGFR-1 and FGFR-2) in the developing umbilical cord (UC) on days 40, 60, 75 and 90 of pregnancy and after the physiological delivery in the pig (day 114). qPCR analysis demonstrated an increase in FGF-1 and FGF-2 mRNA levels beginning on day 75 and on day 114 of pregnancy, respectively. In addition, significantly increased FGFR-1IIIc mRNA expression was also found on day 114. On the other hand, no significant changes in FGFR-2IIIb mRNA expression were observed. Western Blot analysis revealed a decrease in FGF-1 and FGFR-2 protein expression after day 40. Beside an increased protein expression of FGF-2 on day 60, no significant changes in FGFR-1 protein expression were detected. Immunohistochemical staining enabled detection of FGF-FGFR system, with different intensity of immunoreaction in endothelial and tunica media cells of the umbilical vessels and in allantoic duct and amniotic epithelium as well as in myofibroblasts. In conclusion, our results show that members of FGF-FGFR system are expressed specifically in UC structures. Furthermore their day of pregnancy-related expression suggest that they may be an important players during UC formation and development