Journal of Mahani Mathematical Research
Volume:6 Issue: 1, Winter and Spring 2017

‎In this work‎, ‎first the differential equation characterizing position vector‎ ‎of spacelike curve is obtained in Lorentzian plane $mathbb{L}^{2}.$ Then the‎ ‎special curves mentioned above are studied in Lorentzian plane $mathbb{L}%‎‎^{2}.$ Finally some characterizations of these special curves are given in‎ ‎$mathbb{L}^{2}.$‎

Let $f : A rightarrow B$ be a ring homomorphism and $J$ an ideal of $B$. In this paper, we give a necessary and sufficient condition for the amalgamated algebra along an ideal $Abowtie^fJ$ to be $J$-Noetherian. Then we give a characterization for pseudo-irreducible ideals of $Abowtie^fJ$, in special cases.

In this work, we use the formal definition of $k$-slant helix cite{ali2} to obtain the intrinsic equations as well as the position vector for emph{slant-slant helices} which a generalization of emph{general helices} and emph{slant helices}. Also, we present some characterizations theorems for $k$-slant helices and derived, in general form, the intrinsic equations for such curves. Thereafter, from a Salkowski curve, anti-salkowski curve, a curve of constant precession and spherical slant helix, as examples of slant helices, we apply this method to find the parametric representation of some emph{slant-slant} helices by means of intrinsic equations. Finally, the parametric representation and the intrinsic equations of textit{Slakowski slant-slant} and textit{Anti-Slakowski slant-slant} helices have been given.

In the present paper we develop the soliton perturbation theory to find nearly soliton solutions for a perturbed higher-order nonlinear Schr¨odinger (PHNLS) equation. An integral expression for the first-order correction to the wave is found and to avoid the secular terms, the dynamical systems for the soliton parameters are found.