Instanton Solutions for the Universal Hypermultiplet

We expand our previous analysis on fivebrane and membrane instanton solutions in the universal hypermultiplet, including near-extremal multi-centered solutions and mixed fivebrane-membrane charged instantons. The results are most conveniently described in terms of a double-tensor multiplet.Comment: Minor changes, clarification added. Contribution to the proceedings of the 36th International Symposium Ahrenshoop, August 200

N=2 Supersymmetric Theories, Dyonic Charges and Instantons

This paper contains the results of our investigations of BPS instantons and of our work on N=2 supersymmetric gauge theories. The BPS instantons we study appear in type II string theory compactifications on Calabi-Yau threefolds. In the corresponding four-dimensional effective supergravity actions the BPS instantons arise as finite action solutions to the Euclidean equations of motion. For N=2 supersymmetric gauge theories we construct general Lagrangians involving gauge groups with (non-abelian) electric and magnetic (dyonic) charges. In this work a coupling to hypermultiplets is included.Comment: 125 pages, 2 tables, based on Ph.D. thesi

Lagrangians with electric and magnetic charges of N=2 supersymmetric gauge theories

General Lagrangians are constructed for N=2 supersymmetric gauge theories in four space-time dimensions involving gauge groups with (non-abelian) electric and magnetic charges. The charges induce a scalar potential, which, when the charges are regarded as spurionic quantities, is invariant under electric/magnetic duality. The resulting theories are especially relevant for supergravity, but details of the extension to local supersymmetry will be discussed elsewhere. The results include the coupling to hypermultiplets. Without the latter, it is demonstrated how an off-shell representation can be constructed based on vector and tensor supermultiplets.Comment: 34 pages, LaTe

Social Dialogue and Psychosocial Risk Management: Added Value of Manager and Employee Representative Agreement in Risk Perception and Awareness

The present study aimed to explore the added value of managers’ and employee representatives’ agreement in risk perception and awareness in explaining the management of more ‘subjective’ psychosocial risks as compared to the more ‘objective’ traditional OSH risks. The general assumption tested was whether the added value of agreement in risk perception and awareness between these parties would be larger for psychosocial risk management as compared to traditional OSH risk management. European Survey of Enterprises on New and Emerging Risks (ESENER-1) data were used from 7226 enterprises in which both managers and employee representatives were interviewed. Answers by employee representatives and managers to mirror questions on risk perception and awareness were used as independent variables, and answers to questions on risk management by the manager were used as dependent variables. Polynomial regression with response surface analysis was used. Differences in risk perception and awareness between managers and employee representatives explained more variance in psychosocial risk management as compared to more traditional OSH risk management. The implications of these findings and the importance of ‘social dialogue’ particularly in the case of psychosocial risk management as opposed to general OSH management are discussed

Peripartum infections and associated maternal mortality in rural Malawi

Article approval pendingTo assess associations between maternal mortality and severe morbidity and human immunodeficiency virus (HIV) infection, uptake of antiretroviral therapy, obstetric infections, and nonobstetric infections in a rural Malawian district, where the estimated HIV prevalence is 21%

On NS5-brane instantons and volume stabilization

We study general aspects of NS5-brane instantons in relation to the stabilization of the volume modulus in Calabi-Yau compactifications of type II strings with fluxes, and their orientifold versions. These instantons correct the Kahler potential and generically yield significant contributions to the scalar potential at intermediate values of string coupling constant and volume. Under suitable conditions they yield uplifting terms that allow for meta--stable de Sitter vacua.Comment: 29 pages, 3 figures; statements about fields G^a made more precise, added some clarifications, typos correcte

Supergravity description of spacetime instantons

We present and discuss BPS instanton solutions that appear in type II string theory compactifications on Calabi-Yau threefolds. From an effective action point of view these arise as finite action solutions of the Euclidean equations of motion in four-dimensional N=2 supergravity coupled to tensor multiplets. As a solution generating technique we make use of the c-map, which produces instanton solutions from either Euclidean black holes or from Taub-NUT like geometries.Comment: 35 pages, some clarifications adde

Einstein-Maxwell gravitational instantons and five dimensional solitonic strings

We study various aspects of four dimensional Einstein-Maxwell multicentred gravitational instantons. These are half-BPS Riemannian backgrounds of minimal N=2 supergravity, asymptotic to R^4, R^3 x S^1 or AdS_2 x S^2. Unlike for the Gibbons-Hawking solutions, the topology is not restricted by boundary conditions. We discuss the classical metric on the instanton moduli space. One class of these solutions may be lifted to causal and regular multi `solitonic strings', without horizons, of 4+1 dimensional N=2 supergravity, carrying null momentum.Comment: 1+30 page