We present a novel $n$EPT ($n$th-order Eulerian Perturbation Theory) scheme to model the nonlinear density field by summation up $n$th-order fields in perturbation theory. The obtained analytical power spectrum shows excellent agreement with results from all 20 Dark-Quest suites of $N$-body simulations spreading over broad range cosmologies. is much better than conventional two-loop Standard Th...

tension-leg platform (tlp) is a vertically moored floating structure. the platform is permanently mooredby tendons. surge equation of motion of tlp is highly nonlinear because of large displacement and it should be solved with perturbation parameter in time domain. this paper compare the dynamic motion responses of a tlp in regular sea waves obtained by applying three method in time domain usin...

solitons are ubiquitous and exist in almost every area from sky to bottom. for solitons to appear, the relevant equation of motion must be nonlinear. in the present study, we deal with the korteweg-devries (kdv), modied korteweg-de vries (mkdv) and regularised longwave (rlw) equations using homotopy perturbation method (hpm). the algorithm makes use of the hpm to determine the initial expansio...

as an application of hirota bilinear method, perturbation expansion truncated at different levels is used to obtain exact soliton solutions to (2+1)-dimensional nonlinear evolution equation in much simpler way in comparison to other existing methods. we have derived bilinear form of nonlinear evolution equation and using this bilinear form, bilinear backlund transformations and construction of ...

in this paper we apply the homotopy perturbation method to derive the higher-order asymptotic distribution of the eigenvalues and eigenfunctions associated with the linear real second order equation of sturm-liouville type on $[0,pi]$ with neumann conditions $(y'(0)=y'(pi)=0)$ where $q$ is a real-valued sign-indefinite number of $c^{1}[0,pi]$ and $lambda$ is a real parameter.

the compressibility factor of nonassociated chain molecules composed of hard convex core yukawa segments was derived with saft-vr and an extension of the barker-henderson perturbation theory for convex bodies. the temperature-dependent chain and dispersion compressibility factors were derived using the yukawa potential. the effects of temperature, packing fraction, and segment number on the com...

in this research, the effect of the first order magnetic field on the ground-state of a centered hydrogenic donor impurity in a gaas/alas spherical quantum dot has been calculated. the perturbation method has been used within the framework of effective mass approximation for these calculations. overall, the analysis shows that a proper choice of quantum dot radius and magnetic field can signifi...

in this paper, we conduct a comparative study between the homotopy perturbation method (hpm) and adomian’s decomposition method (adm) for analytic treatment of nonlinear volterra integral equations, and we show that the hpm with a specific convex homotopy is equivalent to the adm for these type of equations.