Periodic Instantons in SU(2) Yang-Mills-Higgs Theory

The properties of periodic instanton solutions of the classical SU(2) gauge theory with a Higgs doublet field are described analytically at low energies, and found numerically for all energies up to and beyond the sphaleron energy. Interesting new classes of bifurcating complex periodic instanton solutions to the Yang-Mills-Higgs equations are described.Comment: 11 pages, 3 figures (in 5 included eps files), ReVTeX (minor typos corrected and reference added

Semiclassical Study of Baryon and Lepton Number Violation in High-Energy Electroweak Collisions

We make use of a semiclassical method for calculating the suppression exponent for topology changing transitions in high-energy electroweak collisions. In the Standard Model these processes are accompanied by violation of baryon and lepton number. By using a suitable computational technique we obtain results for s-wave scattering in a large region of initial data. Our results show that baryon and lepton number violation remains exponentially suppressed up to very high energies of at least 30 sphaleron masses (250 TeV). We also conclude that the known analytic approaches inferred from low energy expansion provide reasonably good approximations up to the sphaleron energy (8 TeV) only.Comment: 23 pages, 18 figures. Phys.Rev.D journal version (two references added

Instanton propagator and instanton induced processes in scalar model

The propagator in the instanton background in the $(- \lambda \phi^{4})$ scalar model in four dimensions is studied.Leading and sub-leading terms of its asymptotics for large momenta and its on-shell double residue are calculated analytically. These results are applied to the analysis of the initial-state and initial-final-state corrections and the calculation of the next-to-leading (propagator) correction to the exponent of the cross section of instanton induced multiparticle scattering processes.Comment: 44 pages, 7 postscript figures, LaTe

Schwinger-Dyson approach to non-equilibrium classical field theory

In this paper we discuss a Schwinger-Dyson [SD] approach for determining the time evolution of the unequal time correlation functions of a non-equilibrium classical field theory, where the classical system is described by an initial density matrix at time $t=0$. We focus on $\lambda \phi^4$ field theory in 1+1 space time dimensions where we can perform exact numerical simulations by sampling an ensemble of initial conditions specified by the initial density matrix. We discuss two approaches. The first, the bare vertex approximation [BVA], is based on ignoring vertex corrections to the SD equations in the auxiliary field formalism relevant for 1/N expansions. The second approximation is a related approximation made to the SD equations of the original formulation in terms of $\phi$ alone. We compare these SD approximations as well as a Hartree approximation with exact numerical simulations. We find that both approximations based on the SD equations yield good agreement with exact numerical simulations and cure the late time oscillation problem of the Hartree approximation. We also discuss the relationship between the quantum and classical SD equations.Comment: 36 pages, 5 figure

Nonequilibrium Evolution of Correlation Functions: A Canonical Approach

We study nonequilibrium evolution in a self-interacting quantum field theory invariant under space translation only by using a canonical approach based on the recently developed Liouville-von Neumann formalism. The method is first used to obtain the correlation functions both in and beyond the Hartree approximation, for the quantum mechanical analog of the $\phi^{4}$ model. The technique involves representing the Hamiltonian in a Fock basis of annihilation and creation operators. By separating it into a solvable Gaussian part involving quadratic terms and a perturbation of quartic terms, it is possible to find the improved vacuum state to any desired order. The correlation functions for the field theory are then investigated in the Hartree approximation and those beyond the Hartree approximation are obtained by finding the improved vacuum state corrected up to ${\cal O}(\lambda^2)$. These correlation functions take into account next-to-leading and next-to-next-to-leading order effects in the coupling constant. We also use the Heisenberg formalism to obtain the time evolution equations for the equal-time, connected correlation functions beyond the leading order. These equations are derived by including the connected 4-point functions in the hierarchy. The resulting coupled set of equations form a part of infinite hierarchy of coupled equations relating the various connected n-point functions. The connection with other approaches based on the path integral formalism is established and the physical implications of the set of equations are discussed with particular emphasis on thermalization.Comment: Revtex, 32 pages; substantial new material dealing with non-equilibrium evolution beyond Hartree approx. based on the LvN formalism, has been adde

ARIA 2016: Care pathways implementing emerging technologies for predictive medicine in rhinitis and asthma across the life cycle

The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative commenced during a World Health Organization workshop in 1999. The initial goals were (1) to propose a new allergic rhinitis classification, (2) to promote the concept of multi-morbidity in asthma a

Clinical Complexity Domains, Anticoagulation, and Outcomes in Patients with Atrial Fibrillation: A Report from the GLORIA-AF Registry Phase II and III

Background Clinical complexity is common in atrial fibrillation (AF) patients. We assessed the impact of clinical complexity on oral anticoagulant (OAC) treatment patterns and major adverse outcomes in a contemporary cohort of AF patients.Methods The GLORIA-AF Phase II and III Registry enrolled newly diagnosed AF patients with at least one stroke risk factor. Among patients with CHA(2)DS(2)-VASc score >= 2, we defined four domains of perceived clinical complexity: frail elderly (age >= 75 years and body mass index = 2 of the above conditions. We evaluated the associations between clinical complexity domains and antithrombotic treatment prescription, risk of OAC discontinuation, and major adverse outcomes.Results Among the 29,625 patients included (mean age 69.6 +/- 10.7 years, 44.2% females), 9,504 (32.1%) presented with at least one complexity criterion. Clinical complexity was associated with lower OAC prescription, with stronger associations in frail elderly (odds ratio [OR]: 0.47, 95% confidence interval [CI]: 0.36-0.62) and those with >= 2 complexity domains (OR: 0.50, 95% CI: 0.44-0.57). Risk of OAC discontinuation was higher among frail elderly (hazard ratio [HR]: 1.30, 95% CI: 1.00-1.69), CKD (HR: 1.10, 95% CI: 1.02-1.20), and those with >= 2 complexity domains (HR: 1.39, 95% CI: 1.23-1.57). Clinical complexity was associated with higher risk of the primary outcome of all-cause death, thromboembolism, and major bleeding, with the highest magnitude in those with >= 2 criteria (HR: 1.63, 95% CI: 1.43-1.86).Conclusion In AF patients, clinical complexity influences OAC treatment management, and increases the risk of poor clinical outcomes. These patients require additional efforts, such as integrated care approach, to improve their management and prognosis