18053468
Half-monopole and multimonopole
We would like to present some exact SU(2) Yang–Mills–Higgs monopole solutions of half-integer topological charge. These solutions can be just an isolated half-monopole or a multimonopole with topological magnetic charge ½m where m is a natural number. These static monopole solutions satisfy the first order Bogomol'nyi equations. The axially symmetric one-half monopole gauge potentials possess a Dirac-like string singularity along the negative z-axis. The multimonopole gauge potentials are also singular along the z-axis and possess only mirror symmetries.
119481039
STATIC MONOPOLES AND THEIR ANTICONFIGURATIONS
Recently, we have reported on the existence of some monopoles, multimonopole, and antimonopoles configurations. In this paper we would like to present more monopoles, multimonopole, and antimonopoles configurations of the magnetic ansatz of Ref. 9 when the parameters p and b of the solutions takes different serial values. These exact solutions are a different kind of BPS solution. They satisfy the first order Bogomol'nyi equation but possess infinite energy. They can have radial, axial, or rotational symmetry about the z-axis. We classified these serial solutions as (i) the multimonopole at the origin; (ii) the finitely separated 1-monopoles; (iii) the screening solutions of multimonopole and (iv) the axially symmetric monopole solutions. We also give a construction of their anticonfigurations with all the magnetic charges of poles in the configurations reversed. Half-integer topological magnetic charge multimonopole also exist in some of these series of solutions.
118381576
Particles of One-Half Topological Charge
We would like to show the existence of nite energy SU(2) Yang-MillsHiggs particles of one-half topological charge. The ’t Hooft Abelian magnetic elds of these solutions at spatial innity correspond to the magnetic eld
119564127
Exact Solutions of the Abelian Decomposed Restricted Gauge Potential
We construct new exact solution of the SU(2) Yang‐Mills‐Higgs model by considering Abelian decomposition of the gauge potential. The solution is obtained by considering only the restricted part of the decomposition, where the unrestricted valence part is switched off. The solutions possess free parameters c1, c2 and q that correspond to different physical system of monopoles. Under the limit of c1 = 0, c2 = 1, and q = 1, the solution is that of the Wu‐Yang‐like monopole.
118395102
One Monopole-Antimonopole Pair Solutions
We present new classical generalized one monopole-antimonopole pair solutions of the SU(2) Yang-Mills-Higgs theory with the Higgs field in the adjoint representation. We show that in general the one monopole-antimonopole solution need not be solved by imposing mtheta-winding number to be integer greater than one. We also show that this solution can be solved when m = 1 by transforming the large distance asymptotic solutions to general solutions that depend on a parameter p. Secondly we show that these large distance asymptotic solutions can be further generalized to the Jacobi elliptic functions. We focus our numerical calculation on the Jacobi elliptic functions solution when the nphi-winding number is one and show that this generalized Jacobi elliptic 1-MAP solution possesses lower energy. All these solutions are numerical finite energy non-BPS solutions of the Yang-Mills-Higgs field theory.
8117211
Monopole-antimonopole and vortex rings
The SU(2) Yang-Mills-Higgs theory supports the existence of monopoles, antimonopoles, and vortex rings. In this paper, we would like to present new exact static antimonopole-monopole-antimonopole (A-M-A) configurations. The net magnetic charge of these configurations is always −1, while the net magnetic charge at the origin is always +1 for all positive integer values of the solution’s parameter m. However, when m increases beyond 1, vortex rings appear coexisting with these AMA configurations. The number of vortex rings increases proportionally with the value of m. They are located in space where the Higgs field vanishes along rings. We also show that a single-point singularity in the Higgs field does not necessarily correspond to a structureless 1-monopole at the origin but to a zero-size monopole-antimonopole-monopole (MAM) structure when the solution’s parameter m is odd. This monopole is the Wu-Yang-type monopole and it possesses the Dirac string potential in the Abelian gauge. These exact solutions ...
15254963
Lens Galaxy Properties of SBS 1520+530: Insights from Keck Spectroscopy and AO Imaging
We report on an investigation of the SBS 1520+530 gravitational lens system. We have used archival Hubble Space Telescope (HST) imaging, Keck spectroscopic data, and Keck adaptive optics (AO) imaging to study the lensing galaxy and its environment. The AO imaging has allowed us to fix the lens galaxy properties with a high degree of accuracy when performing the lens modeling, and the data indicate that the lens has an elliptical morphology and perhaps a disk. The new spectroscopic data suggest that previous determinations of the lens redshift may be incorrect, and we report an updated, although inconclusive, value z(lens) = 0.761. We have also spectroscopically confirmed the existence of several galaxy groups at approximately the redshift of the lens system. We create new models of the lens system that explicitly account for the environment of the lens, and we also include improved constraints on the lensing galaxy from our AO imaging. Lens models created with these new data can be well fit with a steeper than isothermal mass slope (α = 2.29, where ρ propto r−α) if H_0 is fixed at 72 km s^(-1) Mpc^(-1); isothermal models require H_0 similar to 50 km s^(-1) Mpc^(-1). The steepened profile may indicate that the lens is in a transient perturbed state caused by interactions with a nearby galaxy.
18491679
Galaxy Number Counts and Implications for Strong Lensing
We compare galaxy number counts in Advanced Camera for Surveys (ACS) fields containing moderate-redshift (0.2 <z <1.0) strong gravitational lenses with those in two control samples: (1) the first square degree of the COSMOS survey, comprising 259 ACS fields and (2) 20 ‘pure-parallel’ fields randomly located on the sky. Through a Bayesian analysis we determine the expectation values (μ0) and confidence levels of the underlying number counts for a range of apertures and magnitude bins. Our analysis has produced the following results: (i) we infer that our control samples are not consistent, with the number counts in the COSMOS sample being significantly higher than in the pure-parallel sample for 21 ≤F814W≤ 23. This result matches those found in previous analyses of COSMOS data using different techniques. (ii) We find that small-sized apertures, centred on strong lenses, are overdense compared with randomly placed apertures in the control samples, even compared to the COSMOS sample. Correcting for the local clustering of elliptical galaxies, based on the average two-point correlation function, reduces this overdensity to the 1-2σ level. Thus, the overdensity of galaxies seen along a typical line of sight to a lens can be explained mostly by the natural clustering of galaxies, rather than being due to lenses lying along otherwise biased lines of sight. However, a larger sample of lenses is needed to see if the remaining bias persists when the lens-field uncertainties are smaller. (iii) There is considerable scatter in the lines of sight to individual lens systems, but quantities that are linearly dependent on the external convergence (e.g. H0) should become unbiased if the extra galaxies that cause the bias can be accounted for in the lens models either through direct modelling or via an informed prior on the external convergence. The number counts can be used to set such an informed prior.
118515768
THE EFFECT OF ENVIRONMENT ON SHEAR IN STRONG GRAVITATIONAL LENSES
Using new photometric and spectroscopic data in the fields of nine strong gravitational lenses that lie in galaxy groups, we analyze the effects of both the local group environment and line-of-sight (LOS) galaxies on the lens potential. We use Monte Carlo simulations to derive the shear directly from measurements of the complex lens environment, providing the first detailed independent check of the shear obtained from lens modeling. We account for possible tidal stripping of the group galaxies by varying the fraction of total mass apportioned between the group dark matter halo and individual group galaxies. The environment produces an average shear of γ = 0.08 (ranging from 0.02 to 0.17), significant enough to affect quantities derived from lens observables. However, the direction and magnitude of the shears do not match those obtained from lens modeling in three of the six four-image systems in our sample (B1422, RXJ1131, and WFI2033). The source of this disagreement is not clear, implying that the assumptions inherent in both the environment and lens model approaches must be reconsidered. If only the local group environment of the lens is included, the average shear is γ = 0.05 (ranging from 0.01 to 0.14), indicating that LOS contributions to the lens potential are not negligible. We isolate the effects of various theoretical and observational uncertainties on our results. Of those uncertainties, the scatter in the Faber-Jackson relation and error in the group centroid position dominate. Future surveys of lens environments should prioritize spectroscopic sampling of both the local lens environment and objects along the LOS, particularly those bright (I< 21.5) galaxies projected within 5' of the lens.
971110
Static potential and local color fields in unquenched three-dimensional lattice QCD
Abstract String breaking by dynamical quarks in (2+1)-d lattice QCD is demonstrated in this project, by measuring the static potential and the local color-electric field strength between a heavy quark and antiquark pair at large separations. Simulations are done for unquenched SU(2) color with two flavors of staggered quarks. An improved gluon action is used which allows simulations to be done on coarse lattices, providing an extremely efficient means to access the quark separations and propagation times at which string breaking occurs. The static quark potential is extracted using only Wilson loop operators and hence no valence quarks are present in the trial states. Results give unambiguous evidence for string breaking as the static quark potential completely saturates at twice the heavy-light meson mass at large separations. It is also shown that the local color-electric field strength between the quark pair tends toward vacuum values at large separations. Implications of these results for unquenched simulations of QCD in 4-d are drawn.
119217960
Inflating wormholes in the braneworld models
The braneworld model, in which our Universe is a three-brane embedded in a five-dimensional bulk, allows the existence of wormholes, without any violation of the energy conditions. A fundamental ingredient of traversable wormholes is the violation of the null energy condition (NEC). However, in the braneworld models, the stress–energy tensor confined on the brane, threading the wormhole, satisfies the NEC. In conventional general relativity, wormholes existing before inflation can be significantly enlarged by the expanding spacetime. We investigate the evolution of an inflating wormhole in the braneworld scenario, in which the wormhole is supported by the nonlocal braneworld effects. As a first step in our study, we consider the possibility of embedding a four-dimensional braneworld wormhole into a five-dimensional bulk. The conditions for the embedding are obtained by studying the junction conditions for the wormhole geometry, as well as the full set of the five-dimensional bulk field equations. For the description of the inflation, we adopt the chaotic inflation model. We study the dynamics of the braneworld wormholes during the exponential inflation stage, and in the stage of the oscillating scalar field. A particular exact solution corresponding to a zero redshift wormhole is also obtained. The resulting evolution shows that while the physical and geometrical parameters of a zero redshift wormhole decay naturally, a wormhole satisfying some very general initial conditions could turn into a black hole and exist forever.