Transition rates via Bethe ansatz for the spin-1/2 Heisenberg chain

We use the exact determinantal representation derived by Kitanine, Maillet, and Terras for matrix elements of local spin operators between Bethe wave functions of the one-dimensional s=1/2 Heisenberg model to calculate and numerically evaluate transition rates pertaining to dynamic spin structure factors. For real solutions z_1,...,z_r of the Bethe ansatz equations, the size of the determinants is of order r x r. We present applications to the zero-temperature spin fluctuations parallel and perpendicular to an external magnetic field.Comment: 4 pages, 4 figures and LaTeX-svjour clas

Casimir Effect in Compact Universes

The Casimir effect in compact hyperbolic Universes was numerically obtained in previous publications. In this talk, I expose these results.Comment: 16 pages, 8 figures, Invited talk at the Theoretical Cosmology section of the Tenth Marcel Grossmann Meeting on General Relativity, Rio de Janeiro, Brazil, 20-26 July, 200

Liquid-Crystal Blazed-Grating Beam Deflector

A transmission-type nonmechanical multiple-angle beam-steering device that uses liquid-crystal blazed grating has been developed. Sixteen steering angles with a contrast ratio of 18 has been demonstrated. A detailed analysis of the liquid-crystal and poly(methyl methacrylate) blazed-grating deflector was carried out to provide guidance during the deflector’s development. A manufacturing offset compensation technique is proposed to improve the device’s performance greatly. A hybrid approach utilizing electrically generated blazed grating combined with the cascading approach described here yields in excess of 500 deflecting angles

Holiday Price Rigidity and Cost of Price Adjustment

Using unique retail and wholesale price data for 4,532 products carried by a major Midwestern grocery retailer, we find evidence of significant retail price rigidity during the Thanksgiving through Christmas holiday period relative to the rest of the year. We suggest that this pattern of holiday retail price rigidity is best explained by an increased opportunity cost of changing prices at these stores during the holiday period. Evidence based on discussions with retail managers suggests that during holidays the physical, managerial, and customer costs of changing prices rise considerably. Due to higher store traffic, performing tasks such as restocking shelves, handling customers’ questions and inquiries, running cash registers, cleaning, and bagging, become more urgent during holidays and thus receive priority. As a result, the holiday-period opportunity cost of price adjustment increases dramatically for the stores. The data provide a natural experimental setting to study variation in price rigidity because the products, stores, and surrounding institutional features and arrangements, including the market structure, the contractual arrangements, and the nature of relationships, etc., do not change between holiday and non-holiday weeks.Price Rigidity, Price Flexibility, Cost of Price Adjustment, Menu Cost, Holidays, Thanksgiving Holiday, Christmas Holiday, Scanner Data, Transaction Price Data, Retail Price, Wholesale Price, Natural Experiment, Opportunity Cost of Changing Price

Reply to ``Comment on `Insulating Behavior of λ\lambda-DNA on the Micron Scale' "

In our experiment, we found that the resistance of vacuum-dried $\lambda$-DNA exceeds $10^{14} \Omega$ at 295 K. Bechhoefer and Sen have raised a number of objections to our conclusion. We provide counter arguments to support our original conclusion.Comment: 1 page reply to comment, 1 figur