9,513 research outputs found
Stabilization of the Electroweak Scale in 3-3-1 Models
One way of avoiding the destabilization of the electroweak scale through a
strong coupled regime naturally occurs in models with a Landau-like pole at the
TeV scale. Hence, the quadratic divergence contributions to the scalar masses
are not considered as a problem anymore since a new nonperturbative dynamic
emerges at the TeV scale. This scale should be an intrinsic feature of the
models and there is no need to invoke any other sort of protection for the
electroweak scale. In some models based on the gauge symmetry, a nonperturbative dynamics arise and it stabilizes
the electroweak scale.Comment: 10 pages. Version with some improvements and corrections in the tex
Primeiro relato de Braga patagonica Schödte & Meinert, 1884 (Crustacea: Isopoda) parasitando peixes cultivados no Brasil.
Resumo simples
Properties of Solutions in 2+1 Dimensions
We solve the Einstein equations for the 2+1 dimensions with and without
scalar fields. We calculate the entropy, Hawking temperature and the emission
probabilities for these cases. We also compute the Newman-Penrose coefficients
for different solutions and compare them.Comment: 16 pages, 1 figures, PlainTeX, Dedicated to Prof. Yavuz Nutku on his
60th birthday. References adde
Rotating Dilaton Solutions in 2+1 Dimensions
We report a three parameter family of solutions for dilaton gravity in 2+1
dimensions with finite mass and finite angular momentum. These solutions are
obtained by a compactification of vacuum solutions in 3+1 dimensions with
cylindrical symmetry. One class of solutions corresponds to conical
singularities and the other leads to curvature singularities.Comment: Accepted to be published in Gen. Rel. Grav., added reference
On the Renormalizability of Theories with Gauge Anomalies
We consider the detailed renormalization of two (1+1)-dimensional gauge
theories which are quantized without preserving gauge invariance: the chiral
and the "anomalous" Schwinger models. By regularizing the non-perturbative
divergences that appear in fermionic Green's functions of both models, we show
that the "tree level" photon propagator is ill-defined, thus forcing one to use
the complete photon propagator in the loop expansion of these functions. We
perform the renormalization of these divergences in both models to one loop
level, defining it in a consistent and semi-perturbative sense that we propose
in this paper.Comment: Final version, new title and abstract, introduction and conclusion
rewritten, detailed semiperturbative discussion included, references added;
to appear in International Journal of Modern Physics
Phase segregation on electroactive self-assembled monolayers: a numerical approach for describing lateral interactions between redox centers
A numerical method is proposed in order to differentiate a random distribution from a phase segregation of redox centers on (mixed) SAMs. This approach is compared to Lavironâs interactions model and voltammetric data of nitroxylalkanethiolate SAMs
Sex-related inequalities in management of patients with acute coronary syndrome-results from the EURHOBOP study
Background: Realâworld data from different levels of hospital specialisation would help to understand if differences in management between women and men with acute coronary syndrome (ACS) are still a priority target. We aimed to identify sex inequalities in management of patients with different types of ACS.
Methods: We analysed 1757 patients with a nonâSTâelevation ACS (NSTEACS) and 1184 with ST elevation myocardial infarction (STEMI) or left bundle branch block (nonâclassifiable (NC) ACS (STEMI/NC ACS group), consecutively discharged from ten Portuguese hospitals with different specialisation levels, between 2008 and 2010. We estimated odds ratios (OR) and 95% confidence intervals (95% CI) for the association between sex and the performance of coronary angiography, reperfusion and revascularisation.
Results: Among STEMI/NC ACS, men had higher probability of performing coronary angiography than women (adjusted OR = 1.64, 95% CI: 1.11â2.44), while among NSTEACS patients there was no significant difference by sex (adjusted OR = 1.26, 95% CI: 0.99â1.62). In patients who underwent coronary angiography, there was no difference in proportion of women and men submitted to revascularisation, regardless of the ACS type. Although men with STEMI/NC ACS were more likely to undergo reperfusion (crude OR = 2.17, 95% CI: 1.68â2.81), the effect became not significant after multivariable adjustment (adjusted OR = 1.33, 95% CI: 0.96â1.84).
Conclusion: Women diagnosed with STEMI/NC, but not NSTEACS, had lower probability when compared with men to be submitted to coronary angiography. There was no difference in performance of reperfusion and revascularisation by sex.Executive Agency for Health and Consumers, Grant/Award Number: 2008 13 12 - EURHOBOP; Universidade do Porto (EPIUnit), Grant/Award Number: POCI-01-0145-FEDER-006862
New hosts and distribution records of Braga patagonica, a parasite cymothoidae of fishes from the Amazon.
Specimens of Braga patagonica Schiödte & Meinert, 1884 (Isopoda: Cymothoidae) from freshwater fishes deposited in Ichthyological Collection of Amazon National Research Institute (INPA), in central Amazon and from fishes from eastern Amazon (Brazil) were investigated. Prevalence, infection intensity and body measures of B. patagonica for different populations of this cymothoid in wild fishes species from Amazon were carried out. Four species of Serrasalmidae, one Characidae, one Cichlidae, one Cynodontidae, one Curimatidae, one Acestrorhynchidae and one Sciaenidae were recorded as new hosts for B. patagonica in the Amazon. This study indicates a low intensity and low parasitic specificity of B. patagonica, and also recorded the first parasitism by this ectoparasite in farmed Colossoma macropomum, describing its highly pathogenic effect
A note on Kerr/CFT and free fields
The near-horizon geometry of the extremal four-dimensional Kerr black hole
and certain generalizations thereof has an SL(2,R) x U(1) isometry group.
Excitations around this geometry can be controlled by imposing appropriate
boundary conditions. For certain boundary conditions, the U(1) isometry is
enhanced to a Virasoro algebra. Here, we propose a free-field construction of
this Virasoro algebra.Comment: 10 pages, v2: comments and references adde
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