Topology of Knotted Optical Vortices

Optical vortices as topological objects exist ubiquitously in nature. In this paper, by making use of the $\phi$-mapping topological current theory, we investigate the topology in the closed and knotted optical vortices. The topological inner structure of the optical vortices are obtained, and the linking of the knotted optical vortices is also given.Comment: 11 pages, no figures, accepted by Commun. Theor. Phys. (Beijing, P. R. China

Evolution of the Chern-Simons Vortices

Based on the gauge potential decomposition theory and the $\phi$-mapping theory, the topological inner structure of the Chern-Simons-Higgs vortex has been showed in detail. The evolution of CSH vortices is studied from the topological properties of the Higgs scalar field. The vortices are found generating or annihilating at the limit points and encountering, splitting or merging at the bifurcation points of the scalar field $\phi .$Comment: 10 pages, 10 figure

Disclination in Lorentz Space-Time

The disclination in Lorentz space-time is studied in detail by means of topological properties of $\phi$-mapping. It is found the space-time disclination can be described in term of a Dirac spinor. The size of the disclination, which is proved to be the difference of two sets of su(2)% -like monopoles expressed by two mixed spinors, is quantized topologically in terms of topological invariants$-$winding number. The projection of space-time disclination density along an antisymmetric tensor field is characterized by Brouwer degree and Hopf index.Comment: Revtex, 7 page

Neutrino spin oscillations in gravitational fields

We study neutrino spin oscillations in black hole backgrounds. In the case of a charged black hole, the maximum frequency of oscillations is a monotonically increasing function of the charge. For a rotating black hole, the maximum frequency decreases with increasing the angular momentum. In both cases, the frequency of spin oscillations decreases as the distance from the black hole grows. As a phenomenological application of our results, we study simple bipolar neutrino system which is an interesting example of collective neutrino oscillations. We show that the precession frequency of the flavor pendulum as a function of the neutrino number density will be higher for a charged/non-rotating black hole compared with a neutral/rotating black hole respectively.Comment: Replaced with the version accepted for publication in Gravitation and Cosmology, Springer. 10 pages. 4 figure

Effect of Transition Magnetic Moments on Collective Supernova Neutrino Oscillations

We study the effect of Majorana transition magnetic moments on the flavor evolution of neutrinos and antineutrinos inside the core of Type-II supernova explosions. We find non-trivial collective oscillation effects relating neutrinos and antineutrinos of different flavors, even if one restricts the discussion to Majorana transition electromagnetic moment values that are not much larger than those expected from standard model interactions and nonzero neutrino Majorana masses. This appears to be, to the best of our knowledge, the only potentially observable phenomenon sensitive to such small values of Majorana transition magnetic moments. We briefly comment on the effect of Dirac transition magnetic moments and on the consequences of our results for future observations of the flux of neutrinos of different flavors from a nearby supernova explosion.Comment: 11 pages,appendix added, version accepted in JCA

A Review of Global Precipitation Data Sets: Data Sources, Estimation, and Intercomparisons

In this paper, we present a comprehensive review of the data sources and estimation methods of 30 currently available global precipitation data sets, including gauge-based, satellite-related, and reanalysis data sets. We analyzed the discrepancies between the data sets from daily to annual timescales and found large differences in both the magnitude and the variability of precipitation estimates. The magnitude of annual precipitation estimates over global land deviated by as much as 300 mm/yr among the products. Reanalysis data sets had a larger degree of variability than the other types of data sets. The degree of variability in precipitation estimates also varied by region. Large differences in annual and seasonal estimates were found in tropical oceans, complex mountain areas, northern Africa, and some high-latitude regions. Overall, the variability associated with extreme precipitation estimates was slightly greater at lower latitudes than at higher latitudes. The reliability of precipitation data sets is mainly limited by the number and spatial coverage of surface stations, the satellite algorithms, and the data assimilation models. The inconsistencies described limit the capability of the products for climate monitoring, attribution, and model validation

Energy-momentum for Randall-Sundrum models

We investigate the conservation law of energy-momentum for Randall-Sundrum models by the general displacement transform. The energy-momentum current has a superpotential and are therefore identically conserved. It is shown that for Randall-Sundrum solution, the momentum vanishes and most of the bulk energy is localized near the Planck brane. The energy density is $\epsilon = \epsilon_0 e^{-3k \mid y \mid}$.Comment: 13 pages, no figures, v4: introduction and new conclusion added, v5: 11 pages, title changed and references added, accepted by Mod. Phys. Lett.

Neutrinos, Weak Interactions, and r-process Nucleosynthesis

Two of the key issues in understanding the neutron-to-proton ratio in a core-collapse supernova are discussed. One of these is the behavior of the neutrino-nucleon cross sections as supernova energies. The other issue is the many-body properties of the neutrino gas near the core when both one- and two-body interaction terms are included.Comment: To be published in the Proceedings of "International Symposium on Structure of Exotic Nuclei and Nuclear Forces (SENUF 06)", March 2006, Tokyo, Japa

New Spinor Field Realizations of the Non-Critical W3W_{3} String

We investigate the new spinor field realizations of the $W_{3}$ algebra, making use of the fact that the $W_{3}$ algebra can be linearized by the addition of a spin-1 current. We then use these new realizations to build the nilpotent Becchi-Rouet-Stora--Tyutin (BRST) charges of the spinor non-critical $W_{3}$ string.Comment: 8 pages, no figures, revtex4 style, accepted by Chin. Phys. Let