The behavior of a system of coupled fields as some of the particles become very heavy is investigated. By means of a technique expressing the relevant exact Green s functions as functional integrals, the limiting process need only be performed for bare one-particle propagators to get the result for the exact functions. It is shown that the resultant propagators are those for the remaining dnite...

As an alternative method to lattice and perturbative QCD we suggest to include the gluon condensate into the parton propagators [1]. In this way non-perturbative effects are taken into account within the Green functions technique. In the case of a pure gluon gas with energy density ǫ and pressure p the gluon condensate can be related to the interaction measure ∆ = (ǫ− 3p)/T 4 via [2] 〈G〉T = 〈G〉...

The time average of the fully nonlinear current through a double quantum dot, subject to an arbitrary combination of ac and dc voltages, is calculated exactly using the Keldysh nonequilibrium Green function technique. When driven on resonance, the system functions as an efficient electron pump due to Rabi oscillation between the dots. The pumping current is maximum when the coupling to the lead...

In this paper‎, ‎we decide to select the best center nodes‎ ‎of radial basis functions by applying the Multiple Criteria Decision‎ ‎Making (MCDM) techniques‎. ‎Two methods based on radial basis‎ ‎functions to approximate the solution of partial differential‎ ‎equation by using collocation method are applied‎. ‎The first is based‎ ‎on the Kansa's approach‎, ‎and the second is based on the Hermit...

a numerical method for solving variational problems is presented in this paper. the method is based upon hybrid of hartley functions approximations. the properties of hybrid functions which are the combinations of block-pulse functions and hartley functions are first presented. the operational matrix of integration is then utilized to reduce the variational problems to the solution of algebraic...

Housing is viewed as a collection of characteristics that are used to satisfy goals, such as comfort and visual quality. Identifying the most important functions of facade results in improving quality. In this regard, the facade plays a crucial role in creating the borders of inner space in contact with its surroundings and can be considered as an interface. This study aimed to investigate and ...