Journal of Nonlinear Mathematical Physics最新文献

Abstract

This research paper examines the characteristics of a two-dimensional steady flow involving an incompressible viscous Casson fluid past an elastic surface that is both permeable and convectively heated, with the added feature of slip velocity. In contrast to Darcy’s Law, the current model incorporates the use of Forchheimer’s Law, which accounts for the non-linear resistance that becomes significant at higher flow velocities. The accomplishments of this study hold significant relevance, both in terms of theoretical advancements in mathematical modeling of Casson fluid flow with heat mass transfer in engineering systems, as well as in the context of practical engineering cooling applications. The study takes into account the collective influences of magnetic field, suction mechanism, convective heating, heat generation, viscous dissipation, and chemical reactions. The research incorporates the consideration of fluid properties that vary with respect to temperature or concentration, and solves the governing equations by employing similarity transformations and the shooting approach. The heat transfer process is significantly affected by the presence of heat generation and viscous dissipation. Furthermore, the study illustrates and presents the impact of various physical factors on the dimensionless temperature, velocity, and concentration. From an engineering perspective, the local Nusselt number, the skin friction, and local Sherwood number are also depicted and provided in graphical and tabular formats. In the domains of energy engineering and thermal management in particular, these results have practical relevance in improving our understanding of heat transmission in similar settings. Finally, the thorough comparison analysis reveals a significant level of alignment with the outcomes of the earlier investigations, thus validating the reliability and effectiveness of our obtained results.

In this paper, we establish some general Kastler–Kalau–Walze type theorems on any dimensional manifolds with boundary for twisted Dirac operators.

This paper’s major goal is to provide a numerical approach for estimating solutions to a coupled system of convection–diffusion equations with Robin boundary conditions (RBCs). We devised a novel method that used four homogeneous RBCs to generate basis functions using generalized shifted Legendre polynomials (GSLPs) that satisfy these RBCs. We provide new operational matrices for the derivatives of the developed polynomials. The collocation approach and these operational matrices are utilized to find approximate solutions for the system under consideration. The given system subject to RBCs is turned into a set of algebraic equations that can be solved using any suitable numerical approach utilizing this technique. Theoretical convergence and error estimates are investigated. In conclusion, we provide three illustrative examples to demonstrate the practical implementation of the theoretical study we have just presented, highlighting the validity, usefulness, and applicability of the developed approach. The computed numerical results are compared to those obtained by other approaches. The methodology used in this study demonstrates a high level of concordance between approximate and exact solutions, as shown in the presented tables and figures.

In this work, the impact of the higher-order reactive nonlinearity on very high-amplitude solitons of the cubic–quintic complex Ginzburg–Landau equation is investigated. These high amplitude pulses were found in a previous work in the normal and anomalous dispersion regimes, starting from a singularity found by Akhmediev et al. We focus mainly in the normal dispersion regime, where the energy of such pulses is particularly high. In the presence of the higher-order reactive nonlinearity effect, pulse formation are observed for much higher absolute values of dispersion. Under such effect, the amplitude and the energy of the VHA pulses decrease, while their spectral range shrinks. Numerical computations are in good agreement with the predictions based on the method of moments, in the absence of the higher-order reactive nonlinearity effect. However, in the presence of this effect such agreement becomes mainly qualitative. A region of existence of the very high-amplitude pulses was found in the semi-plane defined by the normal dispersion and nonlinear gain.

Abstract

In this paper, we compute curvatures of Yano connections on three-dimensional Lorentzian Lie groups with some product structure. We define affine algebraic Ricci solitons associated to Yano connections and classify left-invariant affine algebraic Ricci solitons associated to Yano connections on three-dimensional Lorentzian Lie groups.

In this paper, we study the following double phase system which contains the convex nonlinearities. By the use of the Nehari manifold, the existence of one nontrivial solution which has nonnegative energy is obtained.

Abstract

The inverse problem concerns how to reconstruct the operator from given spectral data. The main goal of this paper is to address nonlinear inverse Sturm–Liouville problem with multiple delays. By using a new technique and method: zero function extension, we establish the uniqueness result and practical method for recovering the nonlinear inverse problem from two spectra.

This paper deals with a fully parabolic indirect pursuit–evasion predator–prey system with density-dependent diffusion (u_{t}=Delta (psi _1(w)u)+u(lambda -u+alpha v), v_{t}=Delta (psi _2(z) v)+v(mu -v-beta u), w_{t}=Delta w -w+v, z_{t}=Delta z-z+u) under a smooth bounded domain (Omega subset {mathbb{R}}^2) with homogeneous Neumann boundary conditions, where the parameters (lambda , mu , alpha) and (beta) are assumed to be positive. Through the establishment of appropriate conditions for the density-dependent diffusion functions (psi _1(w)) and (psi _2(z),) it is revealed that a unique classical solution exists for the corresponding initial-boundary problem, which remains uniformly bounded over time.

In the present paper, we introduce a class of F-stochastic operators on a finite-dimensional simplex, each of which is regular, ascertaining that the species distribution in the succeeding generation corresponds to the species distribution in the previous one in the long run. It is proposed a new scheme to define non-homogeneous Markov chains contingent on the F-stochastic operators and given initial data. By means of the uniform ergodicity of the non-homogeneous Markov chain, we define a non-homogeneous (quantum) entangled Markov chain. Furthermore, it is established that the non-homogeneous entangled Markov chain enables (psi)-mixing property.

This study focuses on the integrability and qualitative behaviors of a quadratic differential system

We provide some new perspectives on the system and reveal its diverse properties, including non-integrability in the sense of absence of first integrals, bifurcations of co-dimension one or two, Jacobi instability and dynamics at infinity.