Quantum Cryptography with Orthogonal States?

This is a Comment on Phys Rev Lett 75 (1995) 1239, by Goldenberg and VaidmanComment: 3 pages, LaTeX, 1 figure on separate page Final version in Phys Rev Lett 77 (1996) 326

The Wage Rate Effects of Occupational Labor Market Tightness

Using the May 1981 Current Population Survey tape and occupational labor market conditions data from the Bureau of Labor Statistics, this study tests (1) whether excess demand for labor is directly related to hourly earnings and (2) what effect, if any, controlling for excess demand may have on the estimated gender differential. The data support a direct effect between excess demand and wage rates. With regard to gender effects, females were disproportionately found to be in occupations with more excess demand (in the disequilibrium sense). Though the measured male premium was larger when controlling for labor market conditions, the increase was neither appreciable nor statistically significant.

The History of the Mysterious Eclipses of KH 15D: Asiago Observatory, 1967-1982

We are gathering archival observations to determine the photometric history of the unique and unexplained eclipses of the pre-main-sequence star KH 15D. Here we present a light curve from 1967-1982, based on photographic plates from Asiago Observatory. During this time, the system alternated periodically between bright and faint states, as observed today. However, the bright state was 0.9 mag brighter than the modern value, and the fractional variation between bright and faint states (Delta I = 0.7 mag) was smaller than observed today (3.5 mag). A possible explanation for these findings is that the system contains a second star that was previously blended with the eclipsing star, but is now completely obscured.Comment: Accepted to AJ. 24 pages, 10 figures, 2 tables. v2: Phase error corrected in figures 8 and 1

Extracting Radial Velocities of A- and B-type Stars from Echelle Spectrograph Calibration Spectra

We present a technique to extract radial velocity measurements from echelle spectrograph observations of rapidly rotating stars ($V\sin{i} \gtrsim 50$ km s$^{-1}$). This type of measurement is difficult because the line widths of such stars are often comparable to the width of a single echelle order. To compensate for the scarcity of lines and Doppler information content, we have developed a process that forward-models the observations, fitting the radial velocity shift of the star for all echelle orders simultaneously with the echelle blaze function. We use our technique to extract radial velocity measurements from a sample of rapidly rotating A- and B-type stars used as calibrator stars observed by the California Planet Survey observations. We measure absolute radial velocities with a precision ranging from 0.5-2.0 km s$^{-1}$ per epoch for more than 100 A- and B-type stars. In our sample of 10 well-sampled stars with radial velocity scatter in excess of their measurement uncertainties, three of these are single-lined binaries with long observational baselines. From this subsample, we present detections of two previously unknown spectroscopic binaries and one known astrometric system. Our technique will be useful in measuring or placing upper limits on the masses of sub-stellar companions discovered by wide-field transit surveys, and conducting future spectroscopic binarity surveys and Galactic space-motion studies of massive and/or young, rapidly-rotating stars.Comment: Accepted to ApJ

Optimal distinction between non-orthogonal quantum states

Given a finite set of linearly independent quantum states, an observer who examines a single quantum system may sometimes identify its state with certainty. However, unless these quantum states are orthogonal, there is a finite probability of failure. A complete solution is given to the problem of optimal distinction of three states, having arbitrary prior probabilities and arbitrary detection values. A generalization to more than three states is outlined.Comment: 9 pages LaTeX, one PostScript figure on separate pag

Detecting the invisible universe with neutrinos and dark matter

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 113-118).Recent work in astrophysics has show that most of the matter in the universe is non-luminous. This work investigates two searches for non-luminous matter: hot dark matter formed from cosmic relic neutrinos from the Big Bang, and directional detection of cold dark matter. The cosmic neutrino background is investigated through the KATRIN experiment, using neutrino capture on tritium to search for a signal. A sensitivity at KATRIN of about 10⁴ events per year, or a local overdensity of relic neutrinos of about 3 x 10⁹ is found. Directional detection of cold dark matter provides a unique way to distinguish a dark matter signal from terrestrial backgrounds, using the expected direction of a dark matter wind based on astrophysical parameters. This work presents a new technique for directional dark matter detection--a drift chamber readout using a CCD camera. The backgrounds of this detector are investigated and enumerated, and a dark matter search sets a limit at mX =100 GeV of 3.7 x 10?³³ cm².by Asher C. Kaboth.Ph.D

The effects of height and frequency of previous defoliation on nodulation, nitrogen fixation and regrowth of phasey bean

Inoculated seeds of phasey bean (Macroptilium lathyroides cv. Murray) were sown in a sand culture in a naturally-lit glasshouse, and imgated daily with nitrogen-Free nutrient solution. At early flowering, the plants were either left uncut or cut at node 5 (high) or node 1 (low), retaining the corresponding residual leaf areas of 74, 11 and Ocm 2 plant 1respectively. Following this initial cutting, new shoots were individually harvested at the frequency of one, two, three, four or eight times over a penriod of 56 days in Phase 1. Total dry weight of new shoots, seed yields and nitrogen concentrations in the herbage were assessed. A II plants were allowed to regrow during the next 21-day recovery period in Phase 2. Then, the root systems and plant tops were harvested. Nodulation,nitrogen fixation (total N) and regression analyses on s011Je plant parameters were computed. In Phase 1, cumulative yields of new shoots harvested following high or low-level cutting declined significantly with increasing harvesting frequency, but yield reductions due to low-level cutting were detected only under high harvesting frequencies. In Phase 2, recovery growth was always better following high than low-level cutting, but unexpectedly, the various harvesting frequencies had no effect on recovery growth following high cutting. After low-level cutting, high or low harvesting frequency reduced recovery growth compared with moderately frequent defoliation (two harvests in 56 days), which coincided with early flowering on the new top growth. Recovery growth had a positive linear correlation (r = 0.98 ***) with nitrogen fixation, which was also linearly correlated with nodulation. These results are briefly discussed with reference to the current concept that regrowth of nodulated forage legumes is largely dependent on symbiotic nitrogen fixation