Showing papers on "Gravitational field published in 1992"
TL;DR: In this article, a generic class of theories where gravity is mediated by one tensor field together with an arbitrary number of scalar fields is considered, and the predictions of these theories are worked out in four different observationally relevant regimes.
Abstract: A generic class of theories where gravity is mediated by one tensor field together with an arbitrary number of scalar fields is considered. The predictions of these theories are worked out in four different observationally relevant regimes: (i) quasi-stationary weak fields (solar system conditions); (ii) rapidly varying weak fields (gravitational wave experiments); (iii) quasi-stationary strong fields (motion of systems of compact bodies, i.e. neutron stars or black holes); and (iv) the mixing of strong and radiative field effects in the gravitational radiation of N-compact-body systems. Moreover, the authors derive several significant relations between the theoretical quantities entering these predictions. They show how strong-field-gravity effects in the motion and gravitational radiation of N-compact-body systems can be parametrized by a set of theory parameters that generalize the usual post-Newtonian parameters ( gamma , beta ,. . .) introduced in the context of quasi-stationary weak gravitational fields. These new parameters ( beta 2, beta ', beta 3, beta ",. . .) provide a chart for the yet essentially unexplored domain of strong-gravitational-field effects, and thereby suggest new directions for testing relativistic gravity. This is illustrated by studying in detail a specific two-parameter tensor-bi-scalar theory T( beta ', beta ") which has the same post-Newtonian limit as general relativity but leads to new nonEinsteinian predictions for the various observables that can be extracted from binary pulsar data.
823 citations
TL;DR: This paper derives the leading nonlinear hereditary effects in the generation of gravitational radiation, i.e., the terms in the wave form which depend in an irreducible manner on the entire past history of the source.
Abstract: This paper derives the leading nonlinear hereditary effects in the generation of gravitational radiation, i.e., the terms in the wave form which depend in an irreducible manner on the entire past history of the source. At the quadratically nonlinear order there are two types of hereditary contributions. The first ones are due to the readiation of gravitational waves by the stress-energy distribution of (linear) gravitational waves, and give rise to a net cumulative change in the wave form of bursts ("memory effect"). The second ones come from the backscattering of (linear) gravitational waves emitted in the past onto the constant curvature associated with the total mass of the source ("gravitational-wave tails"). An extension of a previously proposed multipole-moment wave generation formalism allows us to compute explicitly the wave form, including hereditary contributions, up to terms of fractional order ${(\frac{v}{c})}^{4}$. Our results are derived for slow-moving systems of bodies, independently of the strength of their internal gravity. The tail contribution to the far wave-zone field is found to be fully consistent with a corresponding hereditary contribution to the gravitational radiation damping previously derived from a study of the near-zone field.
321 citations
TL;DR: In this article, an algorithm for evolving collisionless stellar systems with density profiles like the R exp 1/4 law is described, using only a few terms in the expansions, and a good fit is obtained for a truncated isothermal distribution, which renders the method appropriate for galaxies with flat rotation curves.
Abstract: The present study describes an algorithm for evolving collisionless stellar systems in order to investigate the evolution of systems with density profiles like the R exp 1/4 law, using only a few terms in the expansions. A good fit is obtained for a truncated isothermal distribution, which renders the method appropriate for galaxies with flat rotation curves. Calculations employing N of about 10 exp 6-7 are straightforward on existing supercomputers, making possible simulations having significantly smoother fields than with direct methods such as tree-codes. Orbits are found in a given static or time-dependent gravitational field; the potential, phi(r, t) is revised from the resultant density, rho(r, t). Possible scientific uses of this technique are discussed, including tidal perturbations of dwarf galaxies, the adiabatic growth of central masses in spheroidal galaxies, instabilities in realistic galaxy models, and secular processes in galactic evolution.
291 citations
TL;DR: The Christodoulou memory is precisely the TT part of the "1/r, Coulomb-type" gravitational field produced by the burst’s gravitons, and it gets built up over the same length of time τbwm as it takes for the source to emit the Gravitons.
Abstract: The "memory" of a gravitational-wave burst is the permanent relative displacement that it imposes on free test masses, or more precisely, the permanent change in the burst’s gravitational-wave field hjkTT. This memory, in general, is equal to the change, from before the burst to afterward, in the transverse-traceless (TT) part of the "1/r, Coulomb-type" gravitational field generated by the four-momenta of the source’s various independent pieces. Christodoulou has recently identified a contribution to a burst’s memory that arises from nonlinearities in the vacuum Einstein field equation. This paper shows that the Christodoulou memory is precisely the TT part of the "1/r, Coulomb-type" gravitational field produced by the burst’s gravitons, and it therefore gets built up over the same length of time τbwm as it takes for the source to emit the gravitons. The sensitivity of broad-band gravitational-wave detectors such as LIGO to the Christodoulou memory is analyzed and discussed.
270 citations
TL;DR: In this paper, the numerous ways of introducing spatial gravitational forces are fit together in a single framework enabling their interrelationships to be clarified, and the framework is then used to treat the acceleration equals force equation and gyroscope precession, both of which are then discussed in the post-Newtonian approximation, followed by a brief examination of the Einstein equations themselves.
264 citations
TL;DR: In this article, a column load of a model atmosphere on a spherical, elastic Earth is presented and they are used to evaluate the contribution of global atmospheric pressure variations to local gravity.
Abstract: SUMMARY
Gravity Green's functions for a column load of a model atmosphere on a spherical, elastic Earth are presented and they are used to evaluate the contribution of global atmospheric pressure variations to local gravity. The Green's functions are found to be relatively insensitive to the details of the model atmosphere, but they are dependent on the temperature at the base of the column, and on the relative height difference between the base of the column and the gravity station. The total signal that global pressure systems contribute to gravity is about 30 μgal, of which about 90 per cent is produced by the atmosphere within 50 km of the gravity station. A zone between 50 and 1000km from the gravity station contributes a couple of μgal, as does the remainder of the globe. This pattern, the coherence scale of pressure fluctuations, the time and spatial scales appropriate to the hydrostatic approximation, and the distance of the gravity station from the oceans, suggest a division of the globe into local, regional, and global zones. Data requirements, processing details, and the reliability of the computed signal are different in each zone. The local zone is within about 50 km of the gravity station. Within this zone pressure changes rapidly in time, but is spatially coherent, so that hourly observations of pressure and temperature at the gravity site alone are sufficient to compute an accurate correction, except when a front is passing through. The regional zone extends from the edge of the local zone to between several hundred and a thousand kilometres. The signal from this zone is small and is only weakly coherent with the signal from the central zone, so that a rather sparse array of hourly samples of pressure and temperature are required. The gravity signal from the global zone can reach about a μgal. It varies on a time-scale of days, and is influenced by the response of the oceans to pressure variations. Previously reported observations that the admittance between local pressure and gravity residuals depends on epoch, frequency, or site, are most probably due to incorrect modelling. A proper local, regional, temperature, and global correction can adequately account for the gravity signal from the atmosphere to within a few tens of ngal in the diurnal band, and about 100 ngal in the days to seasonal band, except during extreme weather conditions. The application of the local correction lowers the power spectral density of the gravity residuals in every band from seasonal to hourly. The regional, global, and temperature corrections lower the residual noise in the seasonal and synoptic bands, but are not consistently effective at periods less than about half a day.
218 citations
TL;DR: In this article, a discrete model of euclidean quantum gravity in four dimensions based on a summation over random simplicial manifolds is considered and the phase diagram as a function of the bare gravitational coupling constant is studied in the search for a sensible continuum limit.
199 citations
TL;DR: In this article, a method for determining the nuclear equation of state directly from a knowledge of the masses and radii of neutron stars was developed, assuming only that equilibrium neutron-star matter has the stress-energy tensor of an isotropic fluid with a barotropic equation of states, and that general relativity describes a neutron star's internal gravitational field.
Abstract: A method is developed for determining the nuclear equation of state directly from a knowledge of the masses and radii of neutron stars. This analysis assumes only that equilibrium neutron-star matter has the stress-energy tensor of an isotropic fluid with a barotropic equation of state, and that general relativity describes a neutron star's internal gravitational field. We present numerical examples which illustrate how well this method will determine the equation of state when the appropriate observational data become available.
197 citations
TL;DR: In this article, the authors used the timing of three binary pulsars to test relativistic gravity in the strong-field regime, allowing the measurement of velocity-dependent and nonlinear phenomena separately from the effects of gravitational radiation.
Abstract: Experiments in our Solar System can test relativistic gravity only in the weak-field limit, but systems containing pulsars necessarily involve the effects of strong-field gravity. Timing observations of three binary pulsars yield tight constraints on the nature of gravity in the strong-field regime, allowing the measurement of velocity-dependent and nonlinear phenomena separately from the effects of gravitational radiation. General relativity passes these new experimental tests with complete success.
178 citations
TL;DR: The formulas for the higher-order terms are given for density and velocity fields, and the nonlinear gravitational evolution for the fields and its dependence on the initial spectrum are explicitly given.
Abstract: Equations of self-gravitating systems in the Universe are solved by expanding as perturbation series in Fourier space. The formulas for the higher-order terms are given for density and velocity fields. We apply the formulas to several analytically integrable models whose linear density power spectra obey a single power law, and asymptotically approach the prediction of the cold-dark-matter scenario. We explicitly give the nonlinear gravitational evolution for the fields and its dependence on the initial spectrum.
171 citations
TL;DR: In this paper, the authors present in a concise analytical form two asymptotically flat metrics describing the superposition of the Kerr solution with an arbitrary static vacuum Weyl field which differ in their angular momentum distributions.
Abstract: The authors present in a concise analytical form two asymptotically flat metrics describing the superposition of the Kerr solution with an arbitrary static vacuum Weyl field which differ in their angular momentum distributions. They are then used for the construction of two asymptotically flat generalizations of the Kerr-Newman spacetime possessing the full set of mass-multipole moments able to describe the exterior gravitational field of a charged rotating arbitrary axisymmetric mass.
TL;DR: In this article, a metric-independent σ-models are constructed, which generalise the membrane idea to situations where the target space has fewer dimensions than the base manifold, and invariance of solutions of field equations under arbitrary functional redefinitions of the field quantities is established.
TL;DR: The ratio of nuclear spin-precession frequencies of Hg and Hg atoms for two orientations of magnetic field relative to the Earth's gravitational field is measured to provide a test of the equivalence principle for nuclear spins and sets limits on the magnitude of possible scalar-pseudoscalar interactions which would couple to the spins.
Abstract: We have measured the ratio of nuclear spin-precession frequencies of {sup 199}Hg and {sup 201}Hg atoms for two orientations of magnetic field relative to the Earth's gravitational field. We find that the spin-dependent component of gravitational energy is less than 2.2{times}10{sup {minus}21} eV, a substantial improvement over previous limits. Our result provides a test of the equivalence principle for nuclear spins, and sets limits on the magnitude of possible scalar-pseudoscalar interactions which would couple to the spins.
TL;DR: In this article, high-density Geosat/GM altimetry profiles were obtained for Antarctic waters (6-deg S to 72 deg S) and converted to vertical gravity gradient, using Laplace's equation to directly calculate gravity gradient from vertical deflection grids and Fourier analysis to construct gravity anomalies.
Abstract: High-density (about 2-km profile spacing) Geosat/GM altimetry profiles were obtained for Antarctic waters (6-deg S to 72 deg S) and converted to vertical gravity gradient, using Laplace's equation to directly calculate gravity gradient from vertical deflection grids and Fourier analysis to construct gravity anomalies from two vertical deflection grids. The resultant gravity grids have resolution and accuracy comparable to shipboard gravity profiles. The obtained gravity maps display many interesting and previously uncharted features, such as a propagating rift wake and a large 'leaky transform' along the Pacific-Antarctic Rise.
TL;DR: In this article, the motion of binary systems under the back-reaction of the gravitational radiation generated by the quasi-elliptic and quasi-hyperbolic post-Newtonian motions of the binaries is analyzed.
Abstract: The motion of binary systems under the back-reaction of the gravitational radiation generated by the quasi-elliptic and quasi-hyperbolic post-Newtonian motions of the binaries is analyzed. The angular momentum losses are calculated and together with the already known energy losses, the changes of the eccentricities and semimajor axes derived, allowing the determination of a detailed picture of the radiation damping in binary systems up to the 3.5 post-Newtonian order. The wave-forms of the higher order gravitational radiation are presented. In particular, their dependencies on the periastron shifts are made explicit. Various cases of the motion of the binaries and of the waveforms are shown graphically
TL;DR: In this article, a new atomic cavity consisting of a single horizontal concave mirror placed in the earth's gravitational field is studied, where gravity, by bending the atomic trajectories, plays the role of a second mirror closing the cavity.
Abstract: This paper is devoted to the study of a new atomic cavity consisting of a single horizontal concave mirror placed in the earth gravitational field. Gravity, by bending the atomic trajectories, plays the role of a second mirror closing the cavity. We first discuss the stability criterion for this cavity, assuming that the mirror has a parabolic shape. We then derive the quantum mechanical modes of such a configuration, with particular emphasis on the paraxial (i.e., close to vertical) motion. Finally, we discuss the possibility of populating those modes from an initial cold atomic cloud dropped above the mirror.
TL;DR: In this paper, an adhesion model is used to study the formation process of large-scale structures due to nonlinear gravitational growth of small initial fluctuations in the universe dominated by dark matter.
Abstract: An adhesion model is used to study the formation process of large-scale structures due to nonlinear gravitational growth of small initial fluctuations in the universe dominated by dark matter. The model is compared with 2D N-body simulations with initial power-law spectral indices n = -2, 0, +2, and various cutoffs. It is found that the adhesion model imitates the skeleton of the structure extremely well for the parameters of the initial spectra until the stage when the nonlinear scale reaches the correlation length R(phi) of the initial gravitational potential. The model explains the origin of large-scale coherent sructures, such as superpancakes and superfilaments, as a result of coherent motion of clumps due to large-scale inhomogeneities in the initial gravitational potential. It is found that clumps of mass identified in the N-body simulations correspond to several knots in the adhesion model, which influences the way of calculating the mass distribution function. The distribution functions of velocities and masses of clumps and areas of cells in the adhesion model satisfy self-similar scaling laws of the n = 2 model.
TL;DR: In this paper, a framework of General Relativity is applied to the problem of reduction of high-precision astrometric observations of the order of 1 μarcsec, which is expected to be attained in the not so distant future by means of the space optical interferometers orbiting the Earth.
Abstract: The framework of General Relativity is applied to the problem of reduction of high-precision astrometric observations of the order of 1 μarcsec. Such precision is expected to be attained in the not so distant future by means of the space optical interferometers orbiting the Earth. Theoretical methods are described enabling one to construct astrometric reference systems involving the barycentric system, geocentric system, and satellite (observer) system. The relativistic transformations between the employed reference systems have been derived. The equations of geometric optics for the nonstationary gravitational field of the Solar system have been deduced
TL;DR: In this paper, the authors consider the steady group motions of a rigid body with a fixed point moving in a gravitational field and derive the classical equilibrium and stability conditions for sleeping tops and precessing Lagrange taps, and demonstrate the stability of a family of steady rotations of tilted tops which bifurcate from the branch of sleeping Lagrange lops.
Abstract: We consider the steady group motions of a rigid body with a fixed point moving in a gravitational field. For an asymmetric top, rotation about the axis of gravity is the only permissible group motion; for a Lagrange top, simultaneous rotation about the axis of gravity and spin about the axis of symmetry of the top is permissible. Our analysis of the heavy top follows the reduced energy momentum method of Simo el a1 , which is applicable to a wide range of conservative systems with symmetry. Steady group motions are characterized as solutions of a variational problem on the configuration space; local minima of the amended potential correspond to nonlinearly orbitally stable steady motions. The combination of a low-dimensional configuration space and a relatively large number of parameters that produce substantial qualitative changes in the dynamics makes possible a thorough, detailed analysis, which not only reproduces the classical results for this well known system, but leads to some results which we believe are new. motions of a heavy top with a fixed point. We rederive the classical equilibrium and stability conditions for sleeping tops and precessing Lagrange taps, analyse in detail the stability of a family of steady rotations of tilted tops which bifurcate from the branch of sleeping tops parametrized by angular velocity, and classify thc possible stability transitions of an arbitrary top as its angular velocity is increased. We obtain a simple, general expression far the charactenstic polynomial of the linearized equations of motion and analyse the linear stability of both sleeping tops and the family of tilted top motions previously mentioned. Finally, we demonstrate the coexistence of stable branches of steadily precessing tops that bifurcate from the branch of sleeping Lagrange lops throughout the range of angular velocities for which the sleeping top is stable.
TL;DR: In this article, the effects of residual gas scattering, wall potentials due to patches, stress, thermal gradients, and contamination states, as well as image-charge-induced dissipation are considered.
Abstract: There are currently proposals to test the weak equivalence principle for antimatter by studying the motion of antiprotons, negative hydrogen ions, positrons, and electrons under gravity. The motions of such charged particles are affected by residual gas, radiation, and electric and magnetic fields, as well as gravity. The electric fields are particularly sensitive to the state of the "shielding" container. This paper reviews, and extends where necessary, the physics of these extraneous influences on the motion of charged particles under gravity. The effects considered include residual gas scattering; wall potentials due to patches, stress, thermal gradients, and contamination states; and image-charge-induced dissipation.
TL;DR: The same theory of semiclassical gravity that predicts Starobinsky inflation (de Sitter-like solutions driven only by higher-order curvature terms) also predicts flat space to be unstable to small perturbations, in accord with observation.
Abstract: The same theory of semiclassical gravity that predicts Starobinsky inflation (de Sitter-like solutions driven only by higher-order curvature terms) also predicts flat space to be unstable to small perturbations. When semiclassical gravity is modified in a way suggested by and consistent with the perturbative nature of its derivation, flat space is predicted to be stable, in accord with observation, but Starobinsky inflation is no longer a solution. The modified semiclassical theory, constrained to only solutions perturbatively expandable in {h bar}, has the same dynamical degrees of freedom as the clasical gravitational field, despite the presence of fourth-order derivatives in the field equations. There are no de Sitter or de Sitter-like self-consistent solutions except in the presence of a cosmological constant, so inflation generated purely by curvature is not predicted. Furthermore, linearized gravitational perturbations in a de Sitter background (with a cosmological constant) show no signs of instability from quantum effects.
TL;DR: In this article, the authors considered a discrete model of euclidean quantum gravity in three dimensions based on a summation over random simplicial manifolds and studied the phase diagram as a function of the cosmological coupling constant and the gravitational coupling constant in the search for a sensible continuum limit.
TL;DR: The gravity effect produced by two and three-dimensional bodies with nonuniform density contrast has been treated by several authors as discussed by the authors, including Cordell and Rao, who extended the line-integral method to obtain the gravity effect for bodies of arbitrary cross-sections, with density contrast varying linearly with depth.
Abstract: The gravity effect produced by two and three-dimensional bodies with nonuniform density contrast has been treated by several authors. One of the first attempts in this direction made by Cordell (1973), who developed a method to compute the gravity effect due to a two-dimensional prism whose density decreases exponentially with depth. A different approach was proposed by Murthy and Rao (1979). They extended the line-integral method to obtain the gravity effect for bodies of arbitrary cross-sections, with density contrast varying linearly with depth. Chai and Hinze (1988) have derived a wavenumber-domain approach to compute the gravity effect due to a vertical prism whose density contrast varies exponentially with depth. Recently, Rao (1990) has developed a closed expression of the gravity field produced by an asymmetrical trapezoidal body whose density varies with depth following a quadratic polynomial.
TL;DR: General conditions are developed for the formation of naked precursory singularities in spherical gravitational collapse and it is argued that they may well be an essentially generic feature of relativistic gravitational collapse.
Abstract: General conditions are developed for the formation of naked precursory (``shell-focusing'') singularities in spherical gravitational collapse. These singularities owe their nakedness to the fact that the gravitational potential fails to be single valued prior to the onset of a true gravitational singularity. It is argued that they do not violate the spirit of cosmic censorship. Rather, they may well be an essentially generic feature of relativistic gravitational collapse.
01 Apr 1992
TL;DR: In this paper, the number of lattice points inside a random domain, D.V. Kertesz and D. Stauffer's model of the Lagrangian of a random lattice point inside a lattice domain, E. del Rio et al chaotic properties of the noncommutative 2-shift, W. Van den Broeck and T. Tel dynamics of growing self-affine surfaces, T. Kawakatsu and K. Vicsek and others.
Abstract: Anisotropic segregation in a gravitational field, K. Binder et al replica symmetry breaking in the ising spin glass in finite dimensions, C. De Dominicis and I. Kondor problems of high-Tc superconductors - the resistivity, C. Enz correction to dynamic scaling for the lambda transition in liquid HE4 III quasi-sealing at the natural boundary, R.A. Ferrell evolution of patterns in rotating Benard convection, H. Haken phase transitions in binary systems in the presence of amphiphilic molecules, T. Kawakatsu and K. Kawasaki droplet dynamics of ising ferromagnets at the critical point, J. Kertesz and D. Stauffer on the number of lattice points inside a random domain, D.V. Kosygin and Ya G. Sinai oscillations and onset of chaos in a driven nonlinear oscillator with possible escape to infinity, E. del Rio et al chaotic properties of the noncommutative 2-shift, W. Thirring Sinai disorder - intermittency in random maps, C. Van den Broeck and T. Tel dynamics of growing self-affine surfaces, T. Vicsek and others.
Patent•
24 Dec 1992TL;DR: In this article, the authors describe methods and apparatus for measuring gravitational and inertial forces, magnetic fields, or wave or radiant energy acting on an object or fluid in space providing an electric tunneling current through a gap between an electrode and an object in space.
Abstract: Methods and apparatus for measuring gravitational and inertial forces, magnetic fields, or wave or radiant energy acting on an object or fluid in space provide an electric tunneling current through a gap between an electrode and that object or fluid in space and vary that gap with any selected one of such forces, magnetic fields, or wave or radiant energy acting on that object or fluid. These methods and apparatus sense a corresponding variation in an electric property of that gap and determine the latter force, magnetic fields, or wave or radiant energy in response to that corresponding variation, and thereby sense or measure such parameters as acceleration, position, particle mass, velocity, magnetic field strength, presence or direction, or wave or radiant energy intensity, presence or direction.
TL;DR: In this article, the eigenvectors of all operators connecting the zeroth, first and second derivatives of the gravitational potential were derived for a 2-D Fourier (flat earth) expansion of these three sets.
Abstract: SUMMARY
The five independent components Γxz, Γyz, Γzz, Γxx - Γyy, and Γxy, of the gravity tensor are measurable by gradiometers. When grouped into {Γzz}, {Γxz, Γyz} and {Γxx - Γyy, 2Γxy} and expanded into an infinite series of pure-spin spherical harmonic tensors, simple eigenvalue connections can be derived between these three sets and the spherical harmonic expansion of the gravity potential. The three eigenvalues are (n+ 1)(n+ 2), -(n+ 2)√n(n+ 1) and √(n - 1)n(n+ 1)(n+ 2). This result permits an easy analytical incorporation of all measurable tensor components into a spectral signal and noise analysis of gravity quantities on a sphere. Analogous relations also exist for a 2-D Fourier (flat earth) expansion of these three sets. An additional advantageous feature of the set {Γxx - Γyy, 2Γxy}, besides the simple eigenvalue relation, is its invariance with respect to small position uncertainties, e.g., of the trajectory of the satellite or airplane carrying the gradiometer. Hence a complete framework exists in terms of the eigenvectors of all operators connecting the zeroth, first, and second derivatives of the gravitational potential. At the same time the results facilitate the planning of gradiometer missions and their data analysis.
TL;DR: A careful analysis of solutions near the transition to a black hole shows that the monopole loses its non-Abelian hair as it develops a horizon.
Abstract: Explicit solutions of the coupled Einstein-Yang-Mills-Higgs field equations representing a 't Hooft--Polyakov--type magnetic monopole are constructed, both in and away from the Bogomolny-Prasad-Sommerfield limit. The solutions are seen to tend towards black-hole solutions as the strength of the gravitational coupling is increased, as might be expected. A careful analysis of solutions near the transition to a black hole shows that the monopole loses its non-Abelian hair as it develops a horizon. In certain cases, solutions without a horizon are seen to be unstable to gravitational collapse.
TL;DR: The particularity of the gauge gravitation theory is that Dirac fermion fields possess only Lorentz exact symmetries as mentioned in this paper, and therefore fail to be quantized in accordance with the familiar quantum field theory.
Abstract: The particularity of the gauge gravitation theory is that Dirac fermion fields possess only Lorentz exact symmetries. It follows that different tetrad gravitational fieldsh define nonisomorphic representationsγh of cotangent vectors to a space-time manifoldX4 by Dirac'sγ-matrices on fermion fields. One needs these representations in order to construct the Dirac operator defined in terms of jet spaces. As a consequence, gravitational fieldsh fail to form an affine space modeled after any vector space of deviationsh'−h of some background fieldh. They therefore fail to be quantized in accordance with the familiar quantum field theory. At the same time, deformations of representationγh describe deviationsσ ofh such thath +σ is not a gravitational field. These deviations form a vector space, i.e., satisfy the superposition principle. Their Lagrangian, however, differs from familiar Lagrangians of gravitation theory. For instance, it contains masslike terms.
TL;DR: In this article, the authors present a new index of measurements of weak effects, using the original bibliographic work of Gillies as a starting point, but also including citations to the appropriate theoretical papers in the field.
Abstract: The precise measurement of weak effects plays a pivotal role in metrology and in the determination of the fundamental constants. Hence, the possibility of new weak forces, and the related question of non-Newtonian behaviour of the gravitational force, have been of special interest to both measurement scientists and those involved in precise tests of physical laws. To date there is no compelling evidence for any deviations from the predictions of Newtonian gravity in the nonrelativistic weak-field regime. A significant literature on this question has developed over the past few years, and a host of experiments and theoretical scenarios have been discussed. Moreover, a very close relationship exists between the experimental methodologies used to determine the absolute value of the Newtonian gravitational constant G, and those employed in searches for new weak forces and for breakdowns in the inverse-square law of gravity. We have therefore prepared a new index of measurements of such effects, using the original bibliographic work of Gillies as a starting point, but also including citations to the appropriate theoretical papers in the field. The focus of the present version of the index is then studies of the "fifth force", measurements of gravitational effects on antimatter, searches for a spin-component in the gravitational force, and related phenomena.