It is shown that the logical bases of the static perturbation method, which is currently used in static bifurcation analysis, can also be applied to dynamic bifurcations. A two-time version of the Lindstedt–Poincaré Method and the Multiple Scale Method are employed to analyze a bifurcation problem of codimension two. It is found that the Multiple Scale Method furnishes, in a straightforward way...

The Poincaré–Lindstedt method in perturbation theory is used to compute periodic solutions in perturbed differential equations through a nearby periodic orbit of the unperturbed problem. The adaptation of this technique to systems of differential equations of first order could produce meaningful advances in the qualitative analysis of many dynamical systems. In this paper, we present a new symb...

Several problems from mechanical engineering, e.g., vibrations of a spring–mass system with unequal restraints, pendulum impact, gear-pair backlash and friction, etc. are modeled using second-order differential equations involving discontinuous mathematical functions such as signum, Heaviside, modulus, perturbation-like methods parameter expansion, homotopy perturbation, modified Lindstedt–Poin...

We investigate the differentiability of minimal average energy associated to the functionals S ε(u) = ∫ Rd 1 2 |∇u|2 + εV(x, u) dx, using numerical and perturbative methods. We use the Sobolev gradient descent method as a numerical tool to compute solutions of the Euler-Lagrange equations with some periodicity conditions; this is the cell problem in homogenization. We use these solutions to det...

We present a method to obtain arbitrarily accurate solutions for conservative classical oscillators. The method that we propose here works both for small and large nonlinearities and provides simple analytical approximations. A comparison with the standard Lindstedt-Poincaré method is presented, from which the advantages of our method are clear.

A method to recognize polarization constellations is proposed. Described method is based on analysis of torsion and curvature of three-dimensional curve. The three-dimensional curve is defined by states of polarization on the Poincare sphere. Key-Words: Fiber optics; Polarization light; Birefringence; Poincare sphere; Space curve; Frenet frame

Two 4-manifolds are stably diffeomorphic if they become diffeomorphic after connected sum with S × S’s. This paper shows that two closed, orientable, homotopy equivalent, smooth 4-manifolds are stably diffeomorphic provided a certain map from the second homology of the fundamental group with coefficients in Z2 to the L-theory of the group is injective. This injectivity is implied by the Borel/N...