119498503
Baryonic Dark Matter and Big-Bang Nucleosynthesis
The enclosed paper was submitted for publication in Ap.J Lett. in February 1992. It has been rejected on the grounds that it predicts primordial Deuterium abundance which is contradicted by observations and because it disagreed with published analysis and conclusions of previous authors. However, in a recent article in NATURE (14 April 1994) Vol. 368 pp. 599-603, Songalia, Cowie, Hogan and Rugers describe a recent measurement (November 1993) with the Keck 10-m Telescope, of the Deuterium abundance in a high redshift cloud between us and a distant quasar. They find D/H\approx 1.9-2.5 x10^{-4} in good agreement with our prediction D/H=(2.1+\- 0.35)x10^{-4}, which is larger by an order of magnitude than believed before. Songalia et al. found that the baryon density inferred from Big Bang Nucleosynthesis is "consistent with the amount of presently observed luminous matter comprising all the baryons in the Universe" while we found the same. We post here our unpublished 1991 paper, which was reported in international conferences and was distributed only as a preprint, mainly because of its physics and its sad moral: If you submit for publication a correct paper with important results that contradict the "party line" it has only slim chances to be accepted for publication.
118402616
Comment on Jerrold Franklin, Superluminal neutrinos, arXiv:1110.0234v1
A reasonably short antineutrino run using OPERA and/or MINOS may test J. Franklin's explanation of recently claimed $\nu_\mu$ superluminality.
123460442
A new high gain thin gap detector for the opal hadron calorimeter
Abstract A new type of thin gap multiwire gas detector operating in a high gain mode has been developed for use in the OPAL pole tip calorimeter. The detector thickness is only 6.6 mm and its area is 0.61 m 2 . The induced pad readout provides high output pulses which require no amplification. The set-up for the detector mass production and quality control test is described. Results from a test beam set-up that simulates the OPAL pole tip calorimeter are presented and compared with computer simulations.
16978878
What is the statistical significance of the solar neutrino flux problem
Uniform random numbers, not Gaussian random numbers, should have been used with Standard Solar Models to estimate the effect on the neutrino flux of uncertainties in input data. The observed discrepancy is therefore probably quite smaller than currently accepted.
123161968
A new description of high energy antiproton (proton)-proton elastic scattering
Abstract We develop a generalization of the geometric picture for high-energy antiproton (proton)-proton elastic scattering. The eikonal at each impact parameter is considered to have fluctuations about an average value, and is thus characterized by a distribution. A connection to parton branching is made through the specific form of the distribution function for the eikonal. A unified physical theory with significant fluctuations accurately describes the p(p)-p data at both s =546 GeV and 53 GeV. The fluctuation parameter is remarkably well given by that directly observed in multiparticle production.
117256701
Limiting behavior of asymptotically flat gravitational fields
AbstractCouch and Torrence suggest that the vacuum Einstein equations admit a larger class of asymptotically flat solutions than those exhibiting the peeling property. Starting with the assumption that
$$\Psi _0  = O(r^{ - 2 - \varepsilon _0 } )$$
, (d/dr)
$$\Psi _0  = O(r^{ - 3 - \varepsilon _0 } )$$
 and (δ/δxA)
$$\Psi _1  = O(r^{ - 2 - \varepsilon _0 } )$$
, wherexA (A = 2, 3) are angular coordinates, they show that
$$\Psi _1  = O(r^{ - 2 - \varepsilon _1 } )$$
, where ε1⩽ 2 and ε1<ε0;
$$< \varepsilon _0 ;\Psi _2  = O(r^{ - 2 - \varepsilon _2 } )$$
, where ε2 ⩽ 1 and ε1< ε1; and Ψ4 and Ψ3 peel as they would under the stronger peeling conditions. The Winicour-Tamburino energy-momentun and angular momentum integrals for these solutions, in general, diverge. In fact, since Couch and Torrence determine only the radial dependence of the solution, it is not clear that the solutions are well defined. We find that the stronger assumption
$$\Psi _0  = O(r^{ - 3 - \varepsilon _0 } )$$
, (d/dr)
$$\Psi _0  = O(r^{ - 4 - \varepsilon _0 } )$$
, and (δ/δxA)
$$\Psi _0  = O(r^{ - 3 - \varepsilon _0 } )$$
 does result in well-defined solutions for which both the energy-momentum and angular momentum intergrals are not only finite but result in the same expressions as are obtained for peeling space-times. This assumption appears to be the minimal assumption that is necessary for investigating outgoing radiation at null infinity.
119537735
Newman‐Penrose Constants and Their Invariant Transformations
The origin and significance of the Newman‐Penrose (N‐P) constants of the motion are examined from the point of view that constants of the motion generate invariant transformations. Here the calculation makes use of a generalization of Green's theorem to a situation applicable to the coupled Einstein‐Maxwell fields in general relativity. One finds strictly electromagnetic constants generated by an incoming electromagnetic shock wave, with dipole symmetry, at future null infinity. The gravitational constants contain an admixture from the electromagnetic field. They are generated by an incident quadrupole gravitational shock wave at future null infinity (J+). Both the electromagnetic dipole field and the gravitational quadrupole field behave like linearized fields at J+. All higher‐multipole fields do not uncouple from the nonlinear corrections induced by the self‐coupling of the gravitational field and its coupling with the electromagnetic field. It is shown that the gravitational constants are related to t...
119386333
Canonical general relativity on a null surface with coordinate and gauge fixing
We use the canonical formalism developed together with David Robinson to study the Einstein equations on a null surface. Coordinate and gauge conditions are introduced to fix the triad and the coordinates on the null surface. Together with the previously found constraints, these form a sufficient number of second-class constraints so that the phase space is reduced to one pair of canonically conjugate variables: and . The formalism is related to both the Bondi - Sachs and the Newman - Penrose methods of studying the gravitational field at null infinity. Asymptotic solutions in the vicinity of null infinity which exclude logarithmic behaviour require the connection to fall off like after the Minkowski limit. This, of course, gives the previous results of Bondi - Sachs and Newman - Penrose. Introducing terms which fall off more slowly leads to logarithmic behaviour which leaves null infinity intact, allows for meaningful gravitational radiation, but the peeling theorem does not extend to in the terminology of Newman - Penrose. The conclusions are in agreement with those of Chrusciel, MacCallum and Singleton. This work was begun as a preliminary study of a reduced phase space for quantization of general relativity.
123329421
Lorentz-Invariant Equations of Motion of Point Masses in the General Theory of Relativity
After a general discussion of the problem of motion in the general theory of relativity a simple derivation of the law of motion is given for single poles of the gravitational field, which is based on a method originally developed by Mathisson. This law follows from the covariant conservation law for the matter energy-momentum tensor alone, without reference to any field equations, and takes the form of a geodesic of the (unknown) metric. Expanding this metric in terms of a power series in a parameter gamma and using the Minkowski proper time to parametrize the world lines of the particles, the (Lorentz-invariant) form of the approximate laws of motion follows. A method is developed to obtain the equations of motion (including the explicit form of the metric in terms of the particle variables) from Einsiein's field equations. A systematic linearization procedure leads to a series of second-order differential equations for the metric; the nth order approximation of the equations of motion, as well as the explicit form of the matter tensor in (n + l)st order, is obtained as an integrability condition on the (n + l)st order opproximation for the metric. No coordinate conditions are required to obtain themore » general form of the equations of motion; they are needed only to reduce the approximation equations to wave equations and thus to allow their explicit integration in terms of retarded or symmetric potentials. In developing the approximation method it is shown that consistency requires that any set of approximate equations is solved up to'' rather than in'' nth order; this implies that the form of the lower-order metric be maintained, but the motion corresponding to the nth order solutions rather than to lower order ones. In particular, the equations for the first- order metric imply zero-order equations of motion which restrict the particles to zero acceleration; the equations for the second-order metric imply first-order equation of motion involving the first-order metric, but without the previous restriction. In the retarded case the equations of motion contain retarded interactions and radiation terms of the form familiar from electrodynamics; no such terms appear in the symmetric case. The equations of the symmetric case are derivable from a Fokker-type variational principle. The relation of the results obtained to work on Lorentz-invariant equations by other autnors is discussed. In Appendix I a discussion of alternative derivations is prescnted; Appendix II contains remarks on Wheeler-Feynman type considerations for general relativistic equations of motion. (auth)« less
120995906
Degeneracy in loop variables
The small algebra of loop functionals, defined by Rovelli and Smolin, on the Ashtekar phase space of general relativity is studied. Regarded as coordinates on the phase space, the loop functionals become degenerate at certain points. All the degenerate points are found and the corresponding degeneracy is discussed. The intersection of the set of degenerate points with the real slice of the constraint surface is shown to correspond precisely the Goldberg-Kerr solutions. The evolution of the holonomy group of Ashtekar's connection is examined, and the complexification of the holonomy group is shown to be preserved under it. Thus, an observable of the gravitational field is constructed.