16374921
Reality conditions, reducibility, and ghosts.
We examine two methods for incorporating complex first-class constraints into the BRST formalism when the complex conjugates of the constraints are linearly dependent upon the constraints, as is the case for general relativity in the Ashtekar variables. PACS: 03.70.+k, 04.60.Ds, 11.15.−q ? Present Address: Dept. of Physics, U. Toronto, 60 St. George St., Toronto, ON M5S 1A7 Canada
29392446
From scalar to string confinement
We outline a connection between scalar quark confinement, a phenomenologically successful concept heretofore lacking fundamental justification, and QCD. Although scalar confinement does not follow from QCD, there is an interesting and close relationship between them. We develop a simple model intermediate between scalar confinement and the QCD string for illustrative purposes. Finally, we find analytically the bound state spectrum of the light degrees of freedom for a spinless, massless quark in scalar, time-component vector, and string confinement through semi-classical quantization.
17624939
TOPOLOGICAL MASS GENERATION IN 3+1 DIMENSIONS
The 4-dimensional theory of a 1-form Abelian gauge field A coupled to a 2-form (antisymmetric tensor) potential B is studied. The two gauge invariances of the theory admit a coupling mB ∧ F where F is the field strength (F=dA) of A. It is shown that this theory is a unitary, renormalizable theory of a massive spin-one field with no additional degrees of freedom. In this sense, it is a generalization to four dimensions of topological mechanisms in two dimensions (the Schwinger model) and three dimensions (Chern-Simons theory). The issue of spontaneous symmetry breaking is also examined.
119941265
Scalar and QCD string confinement
We compare scalar and string confinement mechanisms. Solutions for the massless quark case are found and discussed.
121348066
Flux tube vibrations and the excited glue spectroscopy
As a step toward a fundamental understanding of hybrid states we demonstrate the close relationship between the relativistic string and lattice simulation results for excited glue states with two fixed color sources.
18449042
Phase space reduction and vortex statistics: An anyon quantization ambiguity.
We examine the quantization of the motion of two charged vortices in a Ginzburg-Landau theory for the fractional quantum Hall effect recently proposed by the first two authors. The system has two second-class constraints which can be implemented either in the reduced phase space or Dirac-Gupta-Bleuler formalism. Using the intrinsic formulation of statistics, we show that these two ways of implementing the constraints are inequivalent unless the vortices are quantized with conventional statistics, either fermionic or bosonic.
5591414
Kinky structure on strings.
The evolution of the linear density of kinks on a cosmic string network is examined, and new possibilities about the behavior of the string network are considered. These include (1) allowing kinky regions to selectively chop off; (2) allowing the kink density to determine the lifetime of kinks; and (3) allowing the mean distance between kinks to determine the length of newly formed loops. Under certain of these assumptions, one obtains results also found by Hindmarsh and by Quashnock and Piran.
16161435
CBR temperature fluctuations induced by gravitational waves in a spatially closed inflationary universe.
Primordial gravitational waves are created during the de Sitter phase of an exponentially-expanding (inflationary) universe, due to quantum zero-point vacuum fluctuations. These waves produce fluctuations in the temperature of the Cosmic Background Radiation (CBR). We calculate the multipole moments of the correlation function for these temperature fluctuations in a spatially-closed Friedman-Robertson-Walker (FRW) cosmological model. The results are compared to the corresponding multipoles in the spatially-flat case. The differences are small unless the density parameter today, $\Omega_0$, is greater than 2. (Submitted to Physical Review D).
32287688
Examples of the Vilkovisky-DeWitt effective action in one-loop quantum gravity.
We present two examples where the contribution of one-loop gravitons to the renormalized stress-energy tensor may be calculated explicitly from both the standard and the Vilkovisky-DeWitt effective action. The renormalization is carried out using the Hadamard renormalization procedure outlined by Allen, Folacci, and Ottewill [Phys. Rev. D 38, 1069 (1988)]. The examples show that the standard and Vilkovisky-DeWitt formulations of quantum field theory lead to different physical predictions at one loop.
27038834
Gauge independence in Hadamard renormalization.
We examine the dependence of the Hadamard-renormalized stress-energy tensor on the gauge-fixing parameter for electromagnetism and one-loop gravity. Simple arguments show that the stress-energy tensor is independent of the parameter.