In the present work, a hybrid of Fourier transform and homotopy perturbation method is developed for solving the non-homogeneous partial differential equations with variable coefficients. The Fourier transform is employed with combination of homotopy perturbation method (HPM), the so called Fourier transform homotopy perturbation method (FTHPM) to solve the partial differential equations. The c...

In this article a numerical method involving classical finite difference scheme on non-uniform grid is constructed for a singularly perturbed convection-diffusion boundary value problem with two small parameters affecting the convection and diffusion terms. The scheme has been analyzed for uniform convergence with respect to both singular perturbation parameters. To support the theoretical erro...

Davies’ method of perturbed semigroups is a classical technique to obtain off-diagonal upper bounds on the heat kernel. However Davies’ method does not apply to anomalous diffusions due to the singularity of energy measures. In this note, we overcome the difficulty by modifying the Davies’ perturbation method to obtain sub-Gaussian upper bounds on the heat kernel. Our computations closely follo...

We proposed Relativistic Quantum Electrodynamics in matters under strong external fields obeying to Finite Schwinger Dyson Formalism. The original Schwinger-Dyson formalism (SD formalism) is generalized for the application to atoms, molecules and electron matters under external fields. Because the generalized formalism has some important differences from original SD formalism widely used in ele...

We describe a new microscopic approach for analyzing interacting electron systems with local moments or, in principle, any local order parameter. We specialize attention to the doped Mott insulator phase of the Hubbard model, where standard weak–coupling perturbation methods fail. A rotationally invariant Stratonovich–Hubbard field is introduced to decouple the static spin components of the int...

in the recent paper, one of the numerical methods without element, for static analysis of thin plates displacement based on classical plates theory (cpt), has been presented. in this method, the domain of problem solving is shown only by the means of a set of nodes, and there is no need to any mesh scheme or element. one of the kinds of element free methods used here is the radial point interpo...

the present research attempts to explain dynamic pull-in instability of functionally graded micro-cantilevers actuated by step dc voltage while the fringing-field effect is taken into account in the vibrational equation of motion. by employing modern asymptotic approach namely homotopy perturbation method with an auxiliary term, high-order frequency-amplitude relation is obtained, then the infl...

in oil industry, spontaneous imbibition is an important phenomenon in recovery from fractured reservoirs which can be defined as spontaneous uptake of a wetting fluid into a porous solid. spontaneous imbibition involves both cocurrent and countercurrent flows. when a matrix block is partially covered by water, oil recovery is dominated by cocurrent imbibition i.e. the production of non wetting ...