Can Heavy WIMPs Be Captured by the Earth?

If weakly interacting massive particles (WIMPs) in bound solar orbits are systematically driven into the Sun by solar-system resonances (as Farinella et al. have shown is the case for many Earth-crossing asteroids), then the capture of high-mass WIMPs by the Earth would be affected dramatically because high-mass WIMPs are captured primarily from bound orbits. WIMP capture would be eliminated for M_x>630 GeV and would be highly suppressed for M_x>~150 GeV. Annihilation of captured WIMPs and anti-WIMPs is expected to give rise to neutrinos coming from the Earth's center. The absence of such a neutrino signal has been used to place limits on WIMP parameters. At present, one does not know if typical WIMP orbits are in fact affected by these resonances. Until this question is investigated and resolved, one must (conservatively) assume that they are. Hence, limits on high-mass WIMP parameters are significantly weaker than previously believed.Comment: 8 pages + 1 figure. Submitted to Ap

Magnetically Stimulated Diffusion of Rydberg Gases

The specific kind of diffusion stimulated (rather than suppressed) by the external magnetic field, which was predicted for the first time by Schmelcher and Cederbaum in 1992, is considered here for the case of high-angular-momentum (i.e., approximately "circular") Rydberg atoms. The coefficient of such diffusion was calculated by a purely analytical approach and was found to be well relevant to the experiments on antihydrogen formation.Comment: REVTeX4, 4 pages, 1 EPS figure; v2: additional numerical estimates and extended discussion in the end of pape

Infrared Line Emission from Planetary Nebulae. I - General Theory

General theory of infrared line emission from planetary nebul

Binary Black Hole Mergers from Planet-like Migrations

If supermassive black holes (BHs) are generically present in galaxy centers, and if galaxies are built up through hierarchical merging, BH binaries are at least temporary features of most galactic bulges. Observations suggest, however, that binary BHs are rare, pointing towards a binary lifetime far shorter than the Hubble time. We show that, regardless of the detailed mechanism, all stellar-dynamical processes are insufficient to reduce significantly the orbital separation once orbital velocities in the binary exceed the virial velocity of the system. We propose that a massive gas disk surrounding a BH binary can effect its merger rapidly, in a scenario analogous to the orbital decay of super-jovian planets due to a proto-planetary disk. As in the case of planets, gas accretion onto the secondary (here a supermassive BH) is integrally connected with its inward migration. Such accretion would give rise to quasar activity. BH binary mergers could therefore be responsible for many or most quasars.Comment: 8 pages, submitted to ApJ Letter

An Analysis of the Purpose and Development of Management Reserve

This study investigates both the purpose and development of management reserve budget as it pertains to the Cost-Schedule Control Systems Criteria outlined in DoD Instruction 5(X)O.2. With the Defense Department facing an environment of shrinking budgets, it is becoming increasingly critical for them to manage their acquisition programs as efficient and effective as possible. The objectives of this study were to gain insight, from both a government and commercial perspective, on both the purpose and the development of the contractor\u27s management reserve budget. Contractor system descriptions and interviews of individuals associated with the government acquisition process were used to document and analyze the objectives of the study. The contractor system descriptions and personal interviews both provided detailed information on the purpose of the contractor\u27s management reserve budget. However, neither data source provided a consistent, objective methodology for developing an accurate and comprehensive contractor\u27s management reserve budget

Current Issues of Highbush Blueberry Producers with Pick-Your-Own Operations in the Northeastern United States

The main purpose of this descriptive study was to identify current issues faced by Northeastern pick-your-own highbush blueberry producers. The study found that average northeastern pick-your-own highbush blueberry producers had been in business 25.99 years and maintained from 0.25 to 45 acres of blueberries. Targeted issues included insects, disease, weeds, wildlife management, and marketing. Top issues identified by highbush blueberry producers were: Japanese beetles, mummy berry, and birds, as well as blueberry maggot, witches broom, weed management, labor/labor costs, weather, government regulation, and spotted wing drosophila. It was found that a majority of the producers did not plan to expand their operations in the next 5 years and had not planted new cultivars since 1999. This study sought to identify contact frequency and form of information exchanged between pick-your-own producers and their local Extension Service. Participants reported they had contact with an extension agent/specialist once every six months and information was exchanged mostly in the form of newsletters and farm visits. Findings indicated that producers preferred to receive information in the form of e-mail and identified online websites as their best source of blueberry information