We present a new formulation of the incompressible Navier-Stokes equation in terms of an auxiliary field that differs from the velocity by a gauge transformation. The gauge freedom allows us to assign simple and specific boundary conditions for both the auxiliary field and the gauge field, thus eliminating the issue of pressure boundary condition in the usual primitive variable formulation. The...

in this present work, the kudryashov method and the functional variable method are used to construct exact solutions of the complex kdv equation. the kudryashov method and the functional variable method are powerful methods for obtaining exact solutions of nonlinear evolution equations.

In this paper, we have proposed a pentadiagonal alternating-direction-implicit (Penta-ADI) finite-difference time-domain (FDTD) method for the two-dimensional Schrödinger equation. Through the separation of complex wave function into real and imaginary parts, a pentadiagonal system of equations for the ADI method is obtained, which results in our Penta-ADI method. The Penta-ADI method is furthe...

In this work we begin a theoretical and numerical investigation on the spectra of evolution operators neutral renewal equations, with stability equilibria periodic orbits in mind. We start from simplest form linear equation one discrete delay fully characterize spectrum its monodromy operator. perform experiments discretizing via pseudospectral collocation, confirming results giving perspective...

A variational basis set motivated by mean-field theory is utilized to describe the Bose-Einstein condensate within adiabatic hyperspherical coordinate framework. The simplest single-orbital variant of this treatment reproduces many ground-state properties predicted Gross-Pitaevskii equation. But a multiorbital improvement yields better representation particle correlations and critical number wh...

boundary integral equations (bie) are reformulations of boundary value problems for partial differential equations. there is a plethora of research on numerical methods for all types of these equations such as solving by discretization which includes numerical integration. in this paper, the neumann problem is reformulated to a bie, and then moving least squares as a meshless method is describe...

Kudryashov in [ Phys. Lett. A 342 (2005) 99-106] used simplest nonlinear differential equations like the Riccati equation, the equation for the Jacobi elliptic function to present a new approach for searching exact solutions of nonlinear partial differential equations. As application, he obtained a kind of exact solutions to the Fisher equation. In this letter, more explicit exact solitary wave...