Energy Momentum Tensor in Conformal Field Theories Near a Boundary

The requirements of conformal invariance for the two point function of the energy momentum tensor in the neighbourhood of a plane boundary are investigated, restricting the conformal group to those transformations leaving the boundary invariant. It is shown that the general solution may contain an arbitrary function of a single conformally invariant variable $v$, except in dimension 2. The functional dependence on $v$ is determined for free scalar and fermion fields in arbitrary dimension $d$ and also to leading order in the \vep expansion about $d=4$ for the non Gaussian fixed point in $\phi^4$ theory. The two point correlation function of the energy momentum tensor and a scalar field is also shown to have a unique expression in terms of $v$ and the overall coefficient is determined by the operator product expansion. The energy momentum tensor on a general curved manifold is further discussed by considering variations of the metric. In the presence of a boundary this procedure naturally defines extra boundary operators. By considering diffeomorphisms these are related to components of the energy momentum tensor on the boundary. The implications of Weyl invariance in this framework are also derived.Comment: 22 pages, TeX with epsf.tex, DAMTP/93-1. (original uuencoded file was corrupted enroute - resubmitted version has uuencoded figures pasted to the ended of the Plain TeX file

Empirical Study Of Tube Wave Suppression For Single Well Seismic Imaging

This report addresses the Idaho National Engineering and Environmental Laboratory's portion of a collaborative effort with Lawrence Berkeley National Laboratory and Sandia National Laboratories on a borehole seismic project called Single Well Seismic Imaging. The INEEL's role was to design, fabricate, deploy, and test a number of passive devices to suppress the energy within the borehole. This energy is generally known as tube waves. Heretofore, tube waves precluded acquisition of meaningful single-well seismic data. This report addresses the INEEL tests, theories, observations, and test results

Ultraviolet Complete Quantum Gravity

An ultraviolet complete quantum gravity theory is formulated in which vertex functions in Feynman graphs are entire functions and the propagating graviton is described by a local, causal propagator. The cosmological constant problem is investigated in the context of the ultraviolet complete quantum gravity.Comment: 11 pages, no figures. Changes to text. Results remain the same. References added. To be published in European Physics Journal Plu

Anomalies, Anomalous U(1)'s and generalized Chern-Simons terms

A detailed analysis of anomalous U(1)'s and their effective couplings is performed both in field theory and string theory. It is motivated by the possible relevance of such couplings in particle physics, as well as a potential signal distinguishing string theory from other UV options. The most general anomaly related effective action is analyzed and parameterized. It contains Stuckelberg, axionic and Chern-Simons-like couplings. It is shown that such couplings are generically non-trivial in orientifold string vacua and are not in general fixed by anomalies. A similar analysis in quantum field theories provides similar couplings. The trilinear gauge boson couplings are also calculated and their phenomenological relevance is advocated. We do not find qualitative differences between string and field theory in this sector.Comment: 52 pages, 2 eps figures, LaTeX, feynmf & youngtab packages (v2 - Minor corrections, references added

General relativity as an effective field theory: The leading quantum corrections

I describe the treatment of gravity as a quantum effective field theory. This allows a natural separation of the (known) low energy quantum effects from the (unknown) high energy contributions. Within this framework, gravity is a well behaved quantum field theory at ordinary energies. In studying the class of quantum corrections at low energy, the dominant effects at large distance can be isolated, as these are due to the propagation of the massless particles (including gravitons) of the theory and are manifested in the nonlocal/nonanalytic contributions to vertex functions and propagators. These leading quantum corrections are parameter-free and represent necessary consequences of quantum gravity. The methodology is illustrated by a calculation of the leading quantum corrections to the gravitational interaction of two heavy masses.Comment: 34 pages, Latex, UMHEP-40

Hidden variables with nonlocal time

To relax the apparent tension between nonlocal hidden variables and relativity, we propose that the observable proper time is not the same quantity as the usual proper-time parameter appearing in local relativistic equations. Instead, the two proper times are related by a nonlocal rescaling parameter proportional to |psi|^2, so that they coincide in the classical limit. In this way particle trajectories may obey local relativistic equations of motion in a manner consistent with the appearance of nonlocal quantum correlations. To illustrate the main idea, we first present two simple toy models of local particle trajectories with nonlocal time, which reproduce some nonlocal quantum phenomena. After that, we present a realistic theory with a capacity to reproduce all predictions of quantum theory.Comment: 16 pages, accepted for publication in Found. Phys., misprints corrected, references update

What can we learn about GW Physics with an elastic spherical antenna?

A general formalism is set up to analyse the response of an arbitrary solid elastic body to an arbitrary metric Gravitational Wave perturbation, which fully displays the details of the interaction antenna-wave. The formalism is applied to the spherical detector, whose sensitivity parameters are thereby scrutinised. A multimode transfer function is defined to study the amplitude sensitivity, and absorption cross sections are calculated for a general metric theory of GW physics. Their scaling properties are shown to be independent of the underlying theory, with interesting consequences for future detector design. The GW incidence direction deconvolution problem is also discussed, always within the context of a general metric theory of the gravitational field.Comment: 21 pages, 7 figures, REVTeX, enhanced Appendix B with numerical values and mathematical detail. See also gr-qc/000605

A Supersymmetric Stueckelberg U(1) Extension of the MSSM

A Stueckelberg extension of the MSSM with only one abelian vector and one chiral superfield as an alternative to an abelian extension with Higgs scalars is presented. The bosonic sector contains a new gauge boson Z' which is a sharp resonance, and a new CP-even scalar, which combines with the MSSM Higgs bosons to produce three neutral CP-even massive states. The neutral fermionic sector has two additional fermions which mix with the four MSSM neutralinos to produce an extended 6x6 neutralino mass matrix. For the case when the LSP is composed mostly of the Stueckelberg fermions, the LSP of the MSSM will be unstable, which leads to exotic decays of sparticles with many leptons in final states. Prospects for supersymmetry searches and for dark matter are discussed.Comment: 10 page

Criticality and Bifurcation in the Gravitational Collapse of a Self-Coupled Scalar Field

We examine the gravitational collapse of a non-linear sigma model in spherical symmetry. There exists a family of continuously self-similar solutions parameterized by the coupling constant of the theory. These solutions are calculated together with the critical exponents for black hole formation of these collapse models. We also find that the sequence of solutions exhibits a Hopf-type bifurcation as the continuously self-similar solutions become unstable to perturbations away from self-similarity.Comment: 18 pages; one figure, uuencoded postscript; figure is also available at http://www.physics.ucsb.edu/people/eric_hirschman