Condensation of Vortex-Strings: Effective Potential Contribution Through Dual Actions

Topological excitations are believed to play an important role in different areas of physics. For example, one case of topical interest is the use of dual models of quantum cromodynamics to understand properties of its vacuum and confinement through the condensation of magnetic monopoles and vortices. Other applications are related to the role of these topological excitations, nonhomogeneous solutions of the field equations, in phase transitions associated to spontaneous symmetry breaking in gauge theories, whose study is of importance in phase transitions in the early universe, for instance. Here we show a derivation of a model dual to the scalar Abelian Higgs model where its topological excitations, namely vortex-strings, become manifest and can be treated in a quantum field theory way. The derivation of the nontrivial contribution of these vacuum excitations to phase transitions and its analogy with superconductivity is then made possible and they are studied here.Comment: 7 pages. Based on a talk given by R. O. Ramos at the Infrared QCD in Rio conference, Rio de Janeiro, Brazil, June 5-9, 200

Assistência pré-natal no Sul do Brasil: cobertura, tendência e disparidades

OBJECTIVE: To estimate coverage, examine trend and assess the disparity reduction regarding household income during prenatal care between mothers living in Rio Grande, state of Rio Grande do Sul, in 2007, 2010, 2013 and 2016. METHODS: This study included all recent mothers living in this municipality, between 1/1 and 12/31 of those years, who had a child weighing more than 500 grams or 20 weeks of gestational age in one of the only two local maternity hospitals. Trained interviewers applied, still in the hospital and up to 48 hours after delivery, a unique and standardized questionnaire, seeking to investigate maternal demographic and reproductive characteristics, the socioeconomic conditions of the family and the assistance received during pregnancy and childbirth. To assess the adequacy of prenatal care, the criteria proposed by Takeda were used, which considers only the number of prenatal appointments and gestational age at initiation, and by Silveira et al., who in addition to these two variables, considers the achievement of some laboratory tests. Chi-square tests were used to compare proportions and assess the linear trend. RESULTS: The total of 10,669 recent mothers were included in this survey (96.8% of the total). Prenatal coverage substantially increased between 2007 and 2016. According to Takeda, it rose from 69% to 80%, while for Silveira et al., it increased from 21% to 55%. This improvement occurred for all income groups (p < 0.01). The disparity between the extreme categories of income reduced, according to Takeda, and increased according to Silveira et al. CONCLUSIONS: The provision of prenatal care, considering only the number of appointments and the early start, occurred in greater proportion among the poorest. However, only the richest recent mothers were contemplated with more elaborate care, such as laboratory tests, which increased the disparities in the provision of prenatal care.OBJETIVO: Estimar a cobertura, examinar a tendência e avaliar se houve redução da disparidade em relação à renda familiar na realização de pré-natal adequado entre puérperas residentes em Rio Grande, RS, nos anos de 2007, 2010, 2013 e 2016. MÉTODOS: Foram incluídas neste estudo todas as puérperas residentes nesse município que, entre 1/1 a 31/12 desses anos, tiveram filho com peso superior a 500 gramas ou 20 semanas de idade gestacional em alguma das duas únicas maternidades locais. Entrevistadoras treinadas aplicaram, ainda no hospital e em até 48 horas após o parto, questionário único e padronizado, buscando investigar as características demográficas e reprodutivas maternas, as condições socioeconômicas da família e a assistência recebida durante a gestação e parto. Para avaliação da adequação do pré-natal, foram utilizados os critérios propostos por Takeda, que considera apenas o número de consultas pré-natais e a idade gestacional de início, e de Silveira et al., que além dessas duas variáveis, leva em conta a realização de alguns testes laboratoriais. Foram utilizados os testes qui-quadrado para comparar proporções e avaliar tendência linear. RESULTADOS: Foram incluídas neste inquérito 10.669 puérperas (96,8% do total). Verificou-se substancial aumento na cobertura de pré-natal adequado entre 2007 e 2016. Segundo Takeda, passou de 69% para 80%, enquanto para Silveira et al. aumentou de 21% para 55%. Essa melhora no período ocorreu para todos os grupos de renda (p < 0,01). Houve redução na disparidade entre as categorias extremas de renda segundo Takeda e aumento acentuado segundo Silveira et al. CONCLUSÕES: A oferta de pré-natal, considerando apenas o número de consultas e o início precoce, ocorreu em maior proporção entre as mais pobres. No entanto, ao oferecer cuidados mais elaborados, como exames laboratoriais, estes alcançaram principalmente as puérperas mais ricas, aumentando assim as disparidades na oferta da assistência pré-natal

Perturbing Topological Field Theories

The abelian Chern-Simons theory is perturbed by introducing local gauge-invariant interaction terms depending on the curvature. The computation of the correlation function of two Wilson lines for two smooth closed nonintersecting curves is reported up to four loops and is shown to be unaffected by radiative corrections. This result ensures the stability of the linking number of the two curves with respect to the local perturbations which may be added to the Chern-Simons action.Comment: 13 pages, 5 figures, corrected some typo