Adapting a method developed for the study of quantum chaos on quantum (metric) graphs [1], spectral ζ functions and trace formulae for discrete Laplacians on graphs are derived. This is achieved by expressing the spectral secular equation in terms of the periodic orbits of the graph, and obtaining functions which belongs to the class of ζ functions proposed originally by Ihara [2], and expanded...

2 Abstract. We investigate perturbed Hamiltonian systems with two degrees of freedom by renormalization group method, which derives a reduced equation called renormalization group equation (RGE) by handling secular terms. We found that RGE is not always a Hamiltonian system. The necessary and sufficient condition that RGE becomes a Hamiltonian system up to the second leading order of a small pa...

A new strategy in deriving the Lense-Thirring effect on the orbital elements of a test body in the field of a rotating mass is presented. The approach adopted in the present work leads, for all the Keplerian orbital elements, to more direct and easy calculation with respect to the original paper by Lense and Thirring. Both periodical and secular terms are worked out. While the latter ones resul...

the first aim of this article is to present zahed’s conceptual–operational model of freedom on the basis of islamic thoughts.  the second goal is to distinguish how freedom would run in the islamic society according to this operational model. finally, we will talk about the differences between this new conceptualization of freedom and the secular one. we will introduce theoretical, social and c...

This work presents the application of the power series method (PSM) to find solutions of partial differential-algebraic equations (PDAEs). Two systems of index-one and index-three are solved to show that PSM can provide analytical solutions of PDAEs in convergent series form. What is more, we present the post-treatment of the power series solutions with the Laplace-Padé (LP) resummation method ...

By using the multiple scale method with the simultaneous introduction of multiple times, we study the propagation of long surface-waves in a shallow inviscid fluid. As a consequence of the requirements of scale invariance and absence of secular terms in each order of the perturbative expansion, we show that the Korteweg-de Vries hierarchy equations do appear in the description of such waves. Fi...

Using the renormalization group method, we improved the first order solution of the long-wavelength expansion of the Einstein equation. By assuming that the renormalization group transformation has the property of Lie group, we can regularize the secular divergence caused by the spatial gradient terms and absorb it to the background seed metric. The solution of the renormalization group equatio...

We apply a multiple–time version of the reductive perturbation method to study long waves as governed by the Boussinesq model equation. By requiring the absence of secular producing terms in each order of the perturbative scheme, we show that the solitary–wave of the Boussinesq equation can be written as a solitary–wave satisfying simultaneously all equations of the KdV hierarchy, each one in a...