Extended Reissner-Nordstr\"om solutions sourced by dynamical torsion

We find a new exact vacuum solution in the framework of the Poincar\'e Gauge field theory with massive torsion. In this model, torsion operates as an independent field and introduces corrections to the vacuum structure present in General Relativity. The new static and spherically symmetric configuration shows a Reissner-Nordstr\"om-like geometry characterized by a spin charge. It extends the known massless torsion solution to the massive case. The corresponding Reissner-Nordstr\"om-de Sitter solution is also compatible with a cosmological constant and additional U(1) gauge fields.Comment: 12 pages, 0 figures, minor changes, references adde

New torsion black hole solutions in Poincar\'e gauge theory

We derive a new exact static and spherically symmetric vacuum solution in the framework of the Poincar\'e gauge field theory with dynamical massless torsion. This theory is built in such a form that allows to recover General Relativity when the first Bianchi identity of the model is fulfilled by the total curvature. The solution shows a Reissner-Nordstr\"om type geometry with a Coulomb-like curvature provided by the torsion field. It is also shown the existence of a generalized Reissner-Nordstr\"om-de Sitter solution when additional electromagnetic fields and/or a cosmological constant are coupled to gravity.Comment: 14 pages, 0 figures, minor changes, references adde

Asymmetric Social Interaction in Economics: Cigarette Smoking Among Young People in the United States, 1992-1999

We analyzed cigarette smoking among people aged 15 - 24 in approximately 90,000 households in the 1992 - 1999 U.S. Current Population Surveys. We modeled social influence as an informational externality, in which each young person's smoking informs her peers about its coolness.' The resulting family smoking game,' with each sibling's smoking endogenous, may have multiple equilibria. We found that the pro-smoking influence of a fellow smoker markedly exceeded the deterrent effect of a non-smoking peer. The phenomenon of asymmetric social influence has implications for financial markets, educational performance, criminal behavior, and other areas of inquiry where peer influence is important.

The Time Varying Effects of Permanent and Transitory Shocks to Real Output

Annual changes in volatility of U.S. real output growth and inflation are documented in data from 1870 to 2009 using a time varying parameter VAR model. Both volatilities rise quickly with World War I and its aftermath, stay relatively high until the end of World War II and drop rapidly until the mid to late-1960s. This Postwar Moderation represents the largest decline in volatilities in our sample, much greater than the Great Moderation that began in the 1980s. Fluctuations in output growth volatility are primarily associated with permanent shocks to output while fluctuations in inflation volatility are primarily accounted for by temporary shocks to output. Conditioning on temporary shocks, inflation and output growth are positively correlated. This finding and the ensuing impulse responses are consistent with an aggregate demand interpretation for the temporary shocks. Our model suggests aggregate demand played a key role in the changes in inflation volatility. Conversely, the two variables are negatively correlated when conditioning on permanent shocks, suggesting that these disturbances are associated primarily with aggregate supply. Our results suggest that aggregate supply played an important role in output volatility fluctuations. Most of the impulse responses support an aggregate supply interpretation of permanent shocks. However, for the pre-World War I period, we find that at longer horizons a permanent increase in output is generally associated with an increase in the price level that is frequently statistically significant. This evidence suggests aggregate demand may have had a long-run positive effect on output during the pre-World War I period.The Great Moderation, stochastic volatility, permanent-transitory decompositions, Markov Chain Monte Carlo, structural vector autoregressions.

The Needle is Moving in CA K-8 Science: Integration with ELA, Integration of the Sciences, and Returning Science as a K-8 Core Subject

This first EII evaluation publication discusses one of the major shifts above, namely the shift to integrated instruction. The integration of science and ELA is the focus of one section, and the integration of the science disciplines (i.e., earth/space, life, and physical) inherent in the MS Integrated Model is the focus of the second. Also discussed at length in this publication is a fundamental shift that is not listed above, but is equally, if not more, important: the need to teach science in the first place. In order for any of the targeted shifts to take place, teachers must devote time to teaching science on a regular basis