Radiation reaction at 3.5 post-Newtonian order in effective field theory

We derive the radiation reaction forces on a compact binary inspiral through 3.5 order in the post-Newtonian expansion using the effective field theory approach. We utilize a recent formulation of Hamilton’s variational principle that rigorously extends the usual Lagrangian and Hamiltonian formalisms to dissipative systems, including the inspiral of a compact binary from the emission of gravitational waves. We find agreement with previous results, which thus provides a non-trivial confirmation of the extended variational principle. The results from this work nearly complete the equations of motion for the generic inspiral of a compact binary with spinning constituents through 3.5 post-Newtonian order, as derived entirely with effective field theory, with only the spin-orbit corrections to the potential at 3.5 post-Newtonian remaining

Long-Term Contracts in Major League Baseball

Long-term deals are one tool that both players and franchises use to manage risk. That tool has been much discussed and empirically tested with respect to player shirking, and has more briefly, and only theoretically, discussed with respect to reducing variance in future payrolls. Our work looks at how patterns of use of long-term contracts are affected by changes in contracting rules established through collective bargaining and by expected changes in franchise revenue streams. To accomplish this, we have assembled the most complete dataset of MLB player contracts to date. We analyze changes in contract length and dollar value across players of different ability levels, at different points in their careers (contract status), by position, across CBA agreements, and further examine if new stadiums and new television deals impact contract terms. We confirm the earlier finding that player performance is systematically higher during contract years than during the early portion of a long-term contract. We also find that inclusion of contract length information significantly reduces the unexplained variation in player salaries.Major League Baseball (MLB); long-term contracts; player salaries and performance; collective bargaining agreements (CBA)

Reply to "Comment on 'Finite size corrections to the radiation reaction force in classical electrodynamics'"

We reply to P. Forg\'acs, T. Herpay, and P. Kov\'acs (arXiv: 1202.6289).Comment: 1 page. To be published in Physical Review Letter

The Train Yard

This piece is about an event that, give or take, happened to me. I write it to create awareness about graffiti as a legitimate sub-culture in our society. More importantly, I\u27d like to show some of the positive outlets for graffiti artists

Paleomagnetism of the Jura-Cretaceous Kyuquot Group, Vancouver Island, British Columbia

The Kyuquot Group is a series of marine clastic deposits of Late Jurassic to Early Cretaceous age located on the NW portion of Vancouver Island. These sediments have been folded, but not metamorphosed, and so provide an attractive target for paleomagnetic study. Results from these rocks fill a significant (50 m.y.) time gap in our knowledge of the paleomagnetic paleolatitude record of Wrangellia. Paleomagnetic results from the underlying Bonanza Volcanics (Symons, 1984) show no significant relative latitudinal displacement of Wrangellia with respect to North America. This, along with geological correlations between other similar-aged clastic sediment units, has led several workers (Brandon et al., 1988, McClelland et al., 1992) to propose that the Kyuquot Group represents a clastic overlap tying Wrangellia to the North American margin. Younger sedimentary rocks from Vancouver Island (the Upper Cretaceous Nanaimo Group) have shallow inclinations, indicative of 2500 km of translation (Enkin et al., 2001). A total of 324 samples from the Jurassic Kapoose Formation and the Cretaceous One Tree Formation were collected. Thermal cleaning of 111 specimens from the Berriasian to Lower Valanginian One Tree Formation revealed two remanence components; one a low- unblocking temperature overprint, the other a high-unblocking temperature component displayed in 77 specimens. The high Tub components pass both an inclination only test and a combined great circle and line-fit fold test after correction for a suspected small block rotation. The fold test results in a 100% bedding corrected direction of Dec. 214.4°, Inc. 85.6°, ± 3.3°, and k = 25.2. Results from the Lower Callovian to Upper Tithonian Kapoose Formation are more scattered. 132 specimens were measured, 66 specimens have a recognizable high Tub component. The high Tub component fails both an inclination only fold test and a combined great circle and line-fit fold test. The Lower Cretaceous One Tree Formation mean inclination corresponds to a paleolatitude of 81.3° ±6.5°, which is 28° (3100km) north of the expected paleolatitude, assuming North American paleogeography. This high paleolatitude, combined with the low latitude results for the Late Cretaceous, is inconsistent with paleolatitudes predicted by models for Wrangellia (WV-1 and WV-2, Debiche et al., 1987). The high paleolatitude is consistent with the postulated revised plate model of Engebretson et al. (1995)

CONSISTENT ESTIMATION OF LONGITUDINAL CENSORED DEMAND SYSTEMS

In this paper we derive a joint continuous/censored demand system suitable for the analysis of commodity demand relationships using panel data. Unobserved heterogeneity is controlled for using a correlated random effects specification and a Generalized Method of Moments framework used to estimate the model in two stages. While relatively small differences in elasticity estimates are found between a flexible specification and one that restricts the relationship between the random effect and budget shares to be time invariant, larger differences are observed between the most flexible random effects model and a pooled cross sectional estimator. The results suggest the limited ability of such estimators to control for preference heterogeneity and unit value endogeneity leads to parameter bias.Research Methods/ Statistical Methods,

UTILIZING EXPECTED REVENUE IN SELECTING OPTIMAL MARKETING ALTERNATIVES FOR FIXED RESOURCE COW/CALF OPERATORS IN THE TEXAS PANHANDLE

Beef cattle enterprises for the 91% of Texas producers with less than 100 cows represent secondary or supplemental enterprises. In most cases the operator is depending on surplus or discretional labor and the alternate use of the physical resources is limited due to topography or environmental factors. These characteristics transform the decision making process from a variable resource allocation problem to a fixed resource problem. Monthly average prices for 300-900 lb stocker steers, divided into 50 lb intervals, are analyzed for three market locations for the period 1992-1999. Consistent price roll back is observed as the price per cwt decreases as the weight increases. However, as the reduction in price is more than offset by the increase in value due to additional weight, the expected revenue per animal increases as weight increases.Livestock Production/Industries,