Is it possible to test directly General Relativity in the gravitational field of the Moon?

In this paper the possibility of measuring some general relativistic effects in the gravitational field of the Moon via selenodetic missions, with particular emphasis to the future Japanese SELENE mission, is investigated. For a typical selenodetic orbital configuration the post-Newtonian Lense-Thirring gravitomagnetic and the Einstein's gravitoelectric effects on the satellites orbits are calculated and compared to the present-day orbit accuracy of lunar missions. It turns out that for SELENE's Main Orbiter, at present, the gravitoelectric periselenium shift, which is the largest general relativistic effect, is 1 or 2 orders of magnitude smaller than the experimental sensitivity. The systematic error induced by the mismodelled classical periselenium precession due to the first even zonal harmonic J2 of the Moon's non-spherical gravitational potential is 3 orders of magnitude larger than the general relativistic gravitoelectric precession. The estimates of this work could be used for future lunar missions having as their goals relativistic measurements as well.Comment: Latex2e, 7 pages, no figures, ets2000.cls and art12.sty used. Major rewriting in introduction. References adde

Static post-Newtonian equivalence of GR and gravity with a dynamical preferred frame

A generally covariant extension of general relativity (GR) in which a dynamical unit timelike vector field is coupled to the metric is studied in the asymptotic weak field limit of spherically symmetric static solutions. The two post-Newtonian parameters known as the Eddington-Robertson-Schiff parameters are found to be identical to those in the case of pure GR, except for some non-generic values of the coefficients in the Lagrangian.Comment: 13 pages; v.2: minor editing, signs corrected, version to appear in PRD; v. 3: signs corrected in eqn (3

Local cosmic string in generalised scalar tensor theory

A recent investigation shows that a local gauge string with a phenomenological energy momentum tensor, as prescribed by Vilenkin, is inconsistent in Brans-Dicke theory. In this work it has been shown that such a string is consistent in a more general scalar tensor theory where $\omega$ is function of the scalar field.A set of solutions of full nonlinear Einstein's equations for interior region of such a string are presented.Comment: 7 pages, latex format, minor changes according to referee's suggestions, revised version submitted in Phys.Rev.

Dynamical study of the empty Bianchi type I model in generalised scalar-tensor theory

A dynamical study of the generalised scalar-tensor theory in the empty Bianchi type I model is made. We use a method from which we derive the sign of the first and second derivatives of the metric functions and examine three different theories that can all tend towards relativistic behaviours at late time. We determine conditions so that the dynamic be in expansion and decelerated at late time.Comment: 18 pages, 3 figures, to appear in General Relativity and Gravitatio

Long-wavelength iteration scheme and scalar-tensor gravity

Inhomogeneous and anisotropic cosmologies are modeled withing the framework of scalar-tensor gravity theories. The inhomogeneities are calculated to third-order in the so-called long-wavelength iteration scheme. We write the solutions for general scalar coupling and discuss what happens to the third-order terms when the scalar-tensor solution approaches at first-order the general relativistic one. We work out in some detail the case of Brans-Dicke coupling and determine the conditions for which the anisotropy and inhomogeneity decay as time increases. The matter is taken to be that of perfect fluid with a barotropic equation of state.Comment: 13 pages, requires REVTeX, submitted to Phys. Rev.

On the possibility of measuring relativistic gravitational effects with a LAGEOS-LAGEOS II-OPTIS-mission

In this paper we wish to preliminary investigate if it would be possible to use the orbital data from the proposed OPTIS mission together with those from the existing geodetic passive SLR LAGEOS and LAGEOS II satellites in order to perform precise measurements of some general relativistic gravitoelectromagnetic effects, with particular emphasis on the Lense-Thirring effect.Comment: Abridged version. 16 pages, no figures, 1 table. First results from the GGM01C Earth gravity model. GRACE data include

On the absence of scalar hair for charged rotating blackholes in non minimally coupled theories

In this work we check the validity of the no scalar hair theorem in charged axisymmetric stationary black holes for a wide class of scalar tensor theories.Comment: Revtex style, 11 pages, major rivisions done, appendix added, title change

The encounter with the unknown: Nurses lived experiences of their responsibility for the care of the patient in the Swedish ambulance service

Registered nurses (RNs) have, according to the Swedish National Board of Health and Welfare, the overall responsibility for the medical care in the ambulance care setting. Bringing RNs into the ambulance service are judged, according to earlier studies, to lead to a degree of professionalism with a higher quality of medical care. Implicitly in earlier studies, the work in the ambulance service involves interpersonal skills. The aim of this study was to describe RNs' experiences of being responsible for the care of the patient in the Swedish ambulance service. A reflective lifeworld approach within the perspective of caring science was used. Five RNs with at least five years experience from care in the ambulance care setting were interviewed. The findings show that the essence of the phenomenon is to prepare and create conditions for care and to accomplish care close to the patient. Three meaning constituents emerged in the descriptions: prepare and create conditions for the nursing care, to be there for the patient and significant others and create comfort for the patient and significant others. The responsibility is a complex phenomenon, with a caring perspective, emerging from the encounter with the unique human being

Modern tests of Lorentz invariance

Motivated by ideas about quantum gravity, a tremendous amount of effort over the past decade has gone into testing Lorentz invariance in various regimes. This review summarizes both the theoretical frameworks for tests of Lorentz invariance and experimental advances that have made new high precision tests possible. The current constraints on Lorentz violating effects from both terrestrial experiments and astrophysical observations are presented.Comment: Modified and expanded discussions of various points. Numerous references added. Version matches that accepted by Living Reviews in Relativit