Constraining Monopoles by Topology: an Autonomous System

We find both analytical and numerical solutions of SU(2) Yang-Mills with an adjoint Higgs field within both closed and open tubes whose sections are spherical caps. This geometry admits a smooth limit in which the space-like metric is flat and, moreover, allows one to use analytical tools which in the flat case are not available. Some of the analytic configurations, in the limit of vanishing Higgs coupling, correspond to magnetic monopoles and dyons living within this tube-shaped domain. However, unlike what happens in the standard case, analytical solutions can also be found in the case in which the Higgs coupling is non-vanishing. We further show that the system admits long-lived breathers.Comment: 20 pages, 9 figures, minor corrections, version accepted in JHE

Quark-composites approach to QCD

We present a perturbative approach to QCD based on quark composites, that is barions and mesons, as fundamental variables.Comment: 4 pages LaTeX, to appear in the proceedings of ``Path Integrals from peV to TeV'', Florence-Italy, August 25-29, 199

Modelling and long-time behaviour for phase transitions with entropy balance and thermal memory conductivity

This paper deals with a thermomechanical model describing phase transitions with thermal memory in terms of balance and equilibrium equations for entropy and microforces, respectively. After a presentation and discussion of the model, the large time behaviour of the solutions to the related integro-differential system of PDE\u27s is investigated

Existence and boundedness of solutions for a singular phase field system

This paper is devoted to the mathematical analysis of a thermomechanical model describing phase transitions in terms of the entropy and order structure balance law. We consider a macroscopic description of the phenomenon and make a presentation of the model. Then, the initial and boundary value problem is addressed for the related PDE system, which contains some nonlinear and singular terms with respect to the temperature variable. Existence of the solution is shown along with the boundedness of both phase variable $\chi$ and absolute temperature $\theta$. Finally, uniqueness is proved in the framework of a source term depending Lipschitz continuously on $\theta$