Critical Temperature and Amplitude Ratios from a Finite-Temperature Renormalization Group

We study \l\f^4 theory using an environmentally friendly finite-temperature renormalization group. We derive flow equations, using a fiducial temperature as flow parameter, develop them perturbatively in an expansion free from ultraviolet and infrared divergences, then integrate them numerically from zero to temperatures above the critical temperature. The critical temperature, at which the mass vanishes, is obtained by integrating the flow equations and is determined as a function of the zero-temperature mass and coupling. We calculate the field expectation value and minimum of the effective potential as functions of temperature and derive some universal amplitude ratios which connect the broken and symmetric phases of the theory. The latter are found to be in good agreement with those of the three-dimensional Ising model obtained from high- and low-temperature series expansions.Comment: 14 pages of LaTeX. Postscript figures available upon request form [email protected]

Temperature Dependence of the QCD Coupling

We present a one-loop calculation of a gauge invariant QCD beta function. Using both momentum and temperature renormalization group equations we investigate the running coupling in the magnetic sector as a function of temperature and momentum scale. At fixed momentum scale we find that, in contrast to $\lambda\phi^4$ or QED, high-temperature QCD is strongly coupled, even after renormalization group improvement. However, if the momentum scale is changed simultaneously with temperature in a specified manner, the coupling decreases. We also point out in what regime dimensional reduction occurs. Both the cases $N_f$ smaller and larger than $\frac{11}{2} N_c$ are discussed.Comment: 10 pages, LaTeX (5 postscript figures available), ITFA-93-11,THU-93/0

The Finite-Temperature Renormalization Group Applied to λϕ⁴ Theory and QCD

In this paper we apply the finite-temperature renormalization group from the point of view of “environmentally friendly” renormalization. We study both λϕ⁴ theory and the magnetic sector of QCD. At one loop level the complete temperature range of λϕ⁴ is successfully described in terms of the parameters of the zero temperature theory. We show also how the critical temperature can be calculated in terms of the latter. For the magnetic sector of QCD, in distinction to λϕ⁴, a one-loop finite temperature renormalization group improvement is not sufficient to describe the high-temperature regime

Symbolic Model Checking for Dynamic Epistemic Logic

Dynamic Epistemic Logic (DEL) can model complex information scenarios in a way that appeals to logicians. However, existing DEL implementations are ad-hoc, so we do not know how the framework really performs. For this purpose, we want to hook up with the best available model-checking and SAT techniques in computational logic. We do this by first providing a bridge: a new faithful representation of DEL models as so-called knowledge structures that allow for symbolic model checking. Next, we show that we can now solve well-known benchmark problems in epistemic scenarios much faster than with existing DEL methods. Finally, we show that our method is not just a matter of implementation, but that it raises significant issues about logical representation and update

Значение и сущность знаний в экономике Украины

Проанализированы взгляды различных авторов на значение и сущность знаний в экономике Украины. Проведены исследования систем классифицирования современной отрасли экономической науки «экономика знаний». Результатом исследований является уточнение термина, а также введение новых типов классификации знаний.Проаналізовані погляди різних авторів на значення і сутність знань в економіці України. Проведені дослідження систем класифікації сучасної галузі економічної науки «економіка знань». Результатом дослідження є уточнення терміну, а також введення нових типів класифікації знань.The paper analyzes the views of different authors on the importance and essence of knowledge in the economy of Ukraine. The system of classification of such branch of the economic science as “knowledge economy” has been investigated. The result of investigation is the term specification, as wel as the introduction of new types of knowledge classification

Percutaneous transhepatic biliary drainage in patients with postsurgical bile leakage and nondilated intrahepatic bile ducts

Objective and Background: Bile leakage is a serious postoperative complication and percutaneous transhepatic biliary drainage (PTBD) may be an option when endoscopic treatment is not feasible. In this retrospective study, we established technical and clinical success rates as well as the complication rates of PTBD in a large group of patients with postoperative bile leakage. Methods: Data on all patients with nondilated intrahepatic bile ducts who underwent a PTBD procedure for the treatment of bile leakage between January 2000 and August 2012 were retrospectively assessed. Data included type of surgery, site of bile leak, previous attempts of bile leak repair, interval between surgery and PTBD placement. Outcome measures were the technical and clinical success rates, the procedure-related complications, and mortality rate. Results: A total of 63 patients were identified; PTBD placement was technically successful in 90.5% (57/63) after one to three attempts. The clinical success rate was 69.8% (44/63). Four major complications were documented (4/63; 6.3%): liver laceration, pneumothorax, pleural empyema, and prolonged hemobilia. One minor complication involved pain. Conclusion

KLN theorem, magnetic mass, and thermal photon production

We study the infrared singularities associated to ultra-soft transverse gluons in the calculation of photon production by a quark-gluon plasma. Despite the fact that the KLN theorem works in this context and provides cancellations of infrared singularities, it does not prevent the production rate of low invariant mass dileptons to be sensitive to the magnetic mass of gluons and therefore the rate to be non perturbative.Comment: 9 pages Latex document, 5 postscript figures, modified figure 5 and slightly updated section