Stationary BPS solutions to dilaton-axion gravity

Stationary four-dimensional BPS solutions to gravity coupled bosonic theories admitting a three-dimensional sigma-model representation on coset spaces are interpreted as null geodesics of the target manifold equipped with a certain number of harmonic maps. For asymptotically flat (or Taub-NUT) space-times such geodesics can be directly parametrized in terms of charges saturating the Bogomol'nyi-Gibbons-Hull bound, and classified according to the structure of related coset matrices. We investigate in detail the ``dilaton-axion gravity'' with one vector field, and show that in the space of BPS solutions an $SO(1,2) \times SO(2)$ classical symmetry is acting. Within the present formalism the most general multicenter (IWP/Taub-NUT dyon) solutions are derived in a simple way. We also discover a large new class of asymptotically flat solutions for which the dilaton and axion charges are constrained only by the BPS bound. The string metrics for these solutions are generically regular. Both the IWP class and the new class contain massless solutions.Comment: 29 pages, Latex, no figures. To be published in Phys. Rev. D. Minor grammatical and bibliographical change

Processing results from drill hole Raddedalen-1, Edge Island, Spitzbergen Archipelago (Report 5750, Leningrad)

Project: Exploration drilling of the hole Raddedalen-1 (Edge Island, Spitzbergen Archipelago). Area of drilling: Edge Island, Svalbard Archipelago, area of the outcrop of Permian silicified limestone on the western shore of the river Kroks. Reasons for drilling: 1. Study of geological-geophysical section of the hole. 2. Obtaining information for regional geological reconstructions and for interpretation marine geophysical materials. 3. Comprehensive study of properties, composition and lithologic-facial features of sedimentary rocks from the geological section. Technical results: The hole was drilled from 02.04.1971 till 10.07.1971. It has penetrated the section of 2823 m and stopped in Ordovician - Early Silurian deposits. Scientific results: 1. Comprehensive lithologic and paleontological studies of drill samples from the hole have allowed to reveal lithologic features and to carry out detailed lithologic and stratigraphic sequence from Early Silurian - Ordovician to Late Permian sedimentary rocks. 2. The hole has crossed the section contained 1949 m of Ordovician - Early Silurian deposits, 468 m of Carboniferous deposits, and 406 m of Permian deposits. 3. The Ordovician and Early Silurian - Ordovician deposits occur in the interval from 874 to 2823 m. They comprise limestones with rare argillite bands and a coal band about 1 m thick at the horizon 1049 m. The Ordovician deposits occur in the interval 1819-2823 m, the Early Silurian - Ordovician deposits occur in the interval 874-1819 m. Presumably the boundary between the Ordovician and Silurian is at the horizon 1649 m. 4. The Carboniferous deposits occur in the interval from 407 to 874 m. The Early Carboniferous deposits occur in the interval 713-874 m, the Middle-Late Carboniferous deposits - in the interval 407-713 m. The Early Carboniferous deposits comprise sandstones; in the lower part of the interval there occur 4 coal bands up to 1.4 m thick. The Middle-Late Carboniferous deposits comprise limestones with bands of quartzitic sandstones in the base. 5. The Permian deposits occur in the interval from 0 to 407 m. The Early Permian deposits occur in the interval 202-407 m, the Late Permian deposits - in the interval 0-202 m. The Early Permian deposits comprise limestones with bands of sandstones, dolomite, and anhydrite. The Late Permian deposits comprise intercalation of limestones (often siliceous ones), quartzitic sandstones, and argillites. 5. The mentioned deposits lay almost horizontally. 6. The Early Carboniferous deposits overlay the Early Silurian - Ordovician ones with stratigraphic disconformity. 7. Density of rocks varies from 2.4 to 2.9 g/ccm. 8. The Early Carboniferous series can be used as a seismic benchmark

OPTICAL CONTROL OF THE INTERNAL CAVITIES OF CAST ARTICLES

The methods and means of visual control of the hard-to-reach channels of castings and moulds on the basis of light-guiding systems of the optical pictures visualization are analyzed. The constructions and technical characteristics of hard and flexible endoscopes for control of basic profilecomposite parts are given

AURORASCIENCE PROJECT: DEVELOPMENT OF THE COMPUTING SYSTEM

The AuroraScience project is a direct collaboration of the Fondazione Bruno Kessler (FBK) with the Istituto Nazionale di Fisica Nucleare (INFN), and the following partner institutions: Fondazione Edmund Mach (FEM), Agenzia Provinciale per la Protonterapia (ATreP), the Physics Department of the University of Trento (FIS-UNITN) and the Dipartimento di Elettronica e Informatica of the University of Padova (DEI-UNIPD). The project is funded by the Provincia Autonoma di Trento (PAT) and by INFN and it is administratively managed by the FBK, through the European Center for Theoretical Studies in Nuclear Physics and Related Areas (ECT*-FBK) and by INFN. The main goal of the project is the development of a computer architecture suitable for high performance scientific computing, the installation of a working prototype of that architecture and the exploitation of this machine for a variety of scientific applications, all requiring the key support of large number crunching capabilities

Higher Partial Waves in . . .

Exclusive measurements of the production of j-mesons in the pp ! ppj reaction have been carried out at excess energies of 16 and 37 MeV above threshold. The distributions are dominated by the proton-proton final state interaction and this influences particularly the energy distribution of the j meson. However, evidence is also presented at the higher energy for the existence of an anisotropy in the angular distributions of the j-meson and also of the final proton-proton pair, probably to be associated with D-waves in this system interfering with the dominant S-wave term. The sign of the j angular anisotropy suggests that ae-exchange is important for this reaction. PACS: 13.60.Le, 13.75.Cs Keywords: j-mesons, threshold production, angular distribution. Draft 24/10/98 Corresponding author: T. Johansson, Department of Radiation Sciences, Uppsala University, S-751 21 Uppsala, Sweden. E-mail: [email protected] The production of j mesons in proton-proton collisions near thresh..

Long-Term Cigarette Smoking Trajectories Among HIV-Seropositive and Seronegative MSM in the Multicenter AIDS Cohort Study

OBJECTIVE: To examine the association between demographic characteristics and long-term smoking trajectory group membership among HIV-seropositive and HIV-seronegative men who have sex with men (MSM). METHODS: A cohort of 6,552 MSM from the Multicenter AIDS Cohort Study (MACS) were asked detailed information about their smoking history since their last follow-up. Group-based trajectory modeling was used to examine smoking behavior and identify trajectory group membership. Because participants enrolled after 2001 were more likely to be younger, HIV-seronegative, non-Hispanic black, and have a high school diploma or less, we also assessed time of enrollment in our analysis. RESULTS: Participants were grouped into 4 distinct smoking trajectory groups: persistent nonsmoker (n=3,737 [55.9%]), persistent light smoker (n=663 [11.0%]), heavy smoker to nonsmoker (n=531 [10.0%]), and persistent heavy smoker (n=1,604 [23.1%]). Compared with persistent nonsmokers, persistent heavy smokers were associated with being enrolled in 2001 and later (adjusted odds ratio [aOR], 2.35; 95% CI, 2.12-2.58), having a high school diploma or less (aOR, 3.22; 95% CI, 3.05-3.39), and being HIV-seropositive (aOR, 1.17; 95% CI, 1.01-1.34). These associations were statistically significant across all trajectory groups for time of enrollment and education but not for HIV serostatus. CONCLUSIONS: The overall decrease of smoking as shown by our trajectory groups is consistent with the national trend. Characteristics associated with smoking group trajectory membership should be considered in the development of targeted smoking cessation interventions among MSM and people living with HIV