QED Thermodynamics at Intermediate Coupling

We discuss reorganizing finite temperature perturbation theory using hard-thermal-loop (HTL) perturbation theory in order to improve the convergence of successive perturbative approximations to the free energy of a gauge theory. We briefly review the history of the technique and present new results for the three-loop HTL-improved approximation for the free energy of QED. We show that the hard-thermal-loop perturbation reorganization improves the convergence of the successive approximations to the QED free energy at intermediate coupling, e ~ 2. The reorganization is gauge invariant by construction, and due to cancellation among various contributions, one can obtain a completely analytic result for the resummed thermodynamic potential at three loops.Comment: 8 pages, 3 figures, Proceedings contribution to "Three Days of Strong Interactions", Wroclaw (Poland), July 200

Comparison of Compliance with Cervical Cancer Screening among Women aged 18 and above in Arkansas and the United States

Introduction: Cervical cancer preys on women without access to preventative screening. Any woman who has developed an invasive case of cervical cancer should be regarded as a failure of screening. Disparities in access to screening, triage, and treatment fuel an uneven distribution in the burden of cervical cancer within the United States; weighing unusually heavy on the Southern States like Arkansas. The purpose of this study was to evaluate demographic and behavioral risk factors for cervical cancer and identify potential barriers which may influence the likelihood of complying with current Pap test recommendations on a state level, in Arkansas, and also a national scale, in the United States. Materials and Methods: National data from the 2014 Behavioral Risk Factor Survey System (BRFSS) was used to collect demographic characteristics and behavioral risk factors among females aged 18 and above in Arkansas and the United States. BFRSS data included a total of 1,587 women in Arkansas and 162,222 in the United States who were aged 18 and above and eligible to receive Pap tests. Women with a medical history of hysterectomy that included the removal of the cervix were excluded from analysis because they are not considered to be medically eligible to receive Pap tests. Results: Socioeconomic status, age, race, and health insurance were significantly associated with likelihood to comply with current screening recommendations among women in both Arkansas and the United States. Arkansan women who had less than a 12-year education (Odds Ratio (OR) = 1.41, 95% Confidence Interval (CI) = 1.04, 1.64) and were without health insurance (OR = 3.56, 95% CI = 1.66, 7.66) were more likely to be non-compliant with Pap testing, which is similar to the finding on the national level. The prevalence of Pap test compliance was significantly lower among women in Arkansas when compared to US average in every sociodemographic sector. Discussion: According to US Census data collected in 2013, Arkansas had the highest cervical cancer incidence of 10.6 per 100,000 person-years, while the national average was 7.7 per 100,000 person-years. Therefore, future population-based cervical cancer interventions in Arkansas should target the promotion of Pap test compliance among the most vulnerable subpopulations (i.e., low socioeconomic status, minority, medically under or uninsured). Organized screening interventions might include offering free or reduced cost Pap testing in both urban and rural locations

On the equilibrium of the magnetopause current layer

Magnetopause current layer equilibriu

The QCD trace anomaly

In this brief report we compare the predictions of a recent next-to-next-to-leading order hard-thermal-loop perturbation theory (HTLpt) calculation of the QCD trace anomaly to available lattice data. We focus on the trace anomaly scaled by T^2 in two cases: N_f=0 and N_f=3. When using the canonical value of mu = 2 pi T for the renormalization scale, we find that for Yang-Mills theory (N_f=0) agreement between HTLpt and lattice data for the T^2-scaled trace anomaly begins at temperatures on the order of 8 T_c while when including quarks (N_f=3) agreement begins already at temperatures above 2 T_c. In both cases we find that at very high temperatures the T^2-scaled trace anomaly increases with temperature in accordance with the predictions of HTLpt.Comment: 12 pages, 4 figures; v3 published versio

Hard-thermal-loop QCD Thermodynamics

Naively resummed perturbative approximations to the thermodynamic functions of QCD do not converge at phenomenologically relevant temperatures. Here we review recent results of a three-loop hard-thermal-loop perturbation theory calculation of the thermodynamic functions of a quark-gluon plasma for general N_c and N_f. We show comparisons of our recent results with lattice data from both the hotQCD and Wuppertal-Budapest groups. We demonstrate that the three-loop hard-thermal-loop perturbation result for QCD thermodynamics agrees with lattice data down to temperatures T ~ 2 T_c.Comment: 8 pages, 2 figures; Talk given at the Symposium on "High Energy Strong Interactions", Aug. 9-13, 2010, Yukawa Institute for Theoretical Physics, Kyoto, Japan; submitted to Prog. Theor. Phys. Supp

On indecomposable modules over the Virasoro algebra

It is proved that an indecomposable Harish-Chandra module over the Virasoro algebra must be (i) a uniformly bounded module, or (ii) a module in Category $\cal O$, or (iii) a module in Category ${\cal O}^-$, or (iv) a module which contains the trivial module as one of its composition factors.Comment: 5 pages, Latex, to appear in Science in China

Gluon Thermodynamics at Intermediate Coupling

We calculate the thermodynamic functions of Yang-Mills theory to three-loop order using the hard-thermal-loop perturbation theory reorganization of finite temperature quantum field theory. We show that at three-loop order hard-thermal-loop perturbation theory is compatible with lattice results for the pressure, energy density, and entropy down to temperatures T ~ 2 - 3 T_c.Comment: 4 pages, 3 figures; v2 - published version

Self-regulation mechanism for charged point defects in hybrid halide perovskites

Hybrid halide perovskites such as methylammonium lead iodide (CH3NH3PbI3) exhibit unusually low free carrier concentrations despite being processed at low-temperatures from solution. We demonstrate, through quantum mechanical calculations, that the origin of this phenomenon is a prevalence of ionic over electronic disorder in stoichiometric materials. Schottky defect formation provides a mechanism to self-regulate the concentration of charge carriers through ionic compensation of charged point defects. The equilibrium charged vacancy concentration is predicted to exceed 0.4% at room temperature. This behaviour, which goes against established defect conventions for inorganic semiconductors, has implications for photovoltaic performance

Competition policy review

This is the first comprehensive review of Australia’s competition laws and policy in over 20 years. The National Competition Policy Review (The Hilmer Review) of 1993 underpinned the development of the National Competition Policy – a co-operative initiative of the Commonwealth and State and Territory governments that the Productivity Commission found contributed to a surge in productivity, directly reduced some prices and stimulated business innovation. The subsequent Review of the Competition Provisions of the Trade Practices Act (The Dawson Review) of 2003 examined the operation of the competition laws and resulted in some strengthening of the provisions. There has been considerable change in the Australian economy since the Hilmer Report of the early 1990s and the boost in productivity that underpinned the growth in living standards over the past two decades is waning. The Competition Policy Review will examine the broader competition framework to ensure that it continues to play a role as a significant driver of productivity improvements and to ensure that the current laws are operating as intended and are effective for all businesses, big and small.   MESSAGE FROM THE PANEL This is our Final Report reviewing Australia’s competition policy, laws and institutions. The Panel undertook a stocktake of the competition policy framework across the Australian economy. Although reforms introduced following the Hilmer Review led to significant improvements in economic growth and wellbeing, the Panel believes that renewed policy effort is required to support growth and wellbeing now and into the future. To this end, we have reviewed Australia’s competition policy, laws and institutions to assess their fitness for purpose. Taken together, our recommendations comprise an agenda of reinvigorated microeconomic reform that will require sustained effort from all jurisdictions. We believe this commitment is necessary if Australia is to boost productivity, secure fiscal sustainability and position our economy to meet the challenges and opportunities of a rapidly changing world. Given the forces for change already bearing on the Australian economy, delaying policy action will make reform more difficult and more sharply felt. An early response will make the reform effort more manageable over time, allowing Australians to enjoy higher living standards sooner rather than later. The recommendations and views expressed in this Final Report draw upon the expertise and experience of each member of the Panel. Importantly, we have also had the benefit of hearing from a wide cross-section of the Australian community and from participants in all sectors of the economy