Mathematics / Matematik

Permanent URI for this collectionhttps://hdl.handle.net/11147/8

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  • Article
    Citation - WoS: 2
    Citation - Scopus: 6
    Dynamical Properties of Generalized Traveling Waves of Exactly Solvable Forced Burgers Equations With Variable Coefficients
    (Elsevier, 2021) Atılgan Büyükaşık, Şirin; Bozacı, Aylin
    The initial value problem for a generalized forced Burgers equation with variable coefficients U-t + ((mu)over dot(t)/mu(t))U + UUX = (1/2 mu(t))U-xx - a(t)U-x + b(t)(xU)(x) - omega(2)(t)x + f(t), x is an element of R , t > 0, is solved using Cole-Hopf linearization and Wei-Norman Lie algebraic approach for finding the evolution operator of the associated linear diffusion type equation. As a result, solution of the initial value problem is obtained in terms of a corresponding linear second-order inhomogeneous ordinary differential equation and a standard Burgers model. Then, using the translation and Galilean invariance of standard Burgers equation, families of generalized nonlinear waves propagating according to a Newtonian type equation of motion are constructed. The influence of the damping, dilatation and forcing terms on the dynamics of shocks, multi-shocks, triangular and N-shaped generalized traveling waves and rational type solutions with moving singularities is investigated. Finally, exactly solvable models with concrete time-variable coefficients are introduced and dynamical properties of certain particular solutions are discussed. (C) 2020 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 12
    Traveling Wave Solutions for Nonlinear Differential-Difference Equations of Rational Types
    (IOP Publishing Ltd., 2016) Aslan, İsmail
    Differential-difference equations are considered to be hybrid systems because the spatial variable n is discrete while the time t is usually kept continuous. Although a considerable amount of research has been carried out in the field of nonlinear differential-difference equations, the majority of the results deal with polynomial types. Limited research has been reported regarding such equations of rational type. In this paper we present an adaptation of the (G′/G)-expansion method to solve nonlinear rational differential-difference equations. The procedure is demonstrated using two distinct equations. Our approach allows one to construct three types of exact traveling wave solutions (hyperbolic, trigonometric, and rational) by means of the simplified form of the auxiliary equation method with reduced parameters. Our analysis leads to analytic solutions in terms of topological solitons and singular periodic functions as well.
  • Article
    Citation - WoS: 17
    Citation - Scopus: 25
    The First Integral Method for Constructing Exact and Explicit Solutions To Nonlinear Evolution Equations
    (John Wiley and Sons Inc., 2012) Aslan, İsmail
    Problems that are modeled by nonlinear evolution equations occur in many areas of applied sciences. In the present study, we deal with the negative order KdV equation and the generalized Zakharov system and derive some further results using the so-called first integral method. By means of the established first integrals, some exact traveling wave solutions are obtained in a concise manner.
  • Article
    Citation - WoS: 23
    Citation - Scopus: 24
    Exact Solutions of Forced Burgers Equations With Time Variable Coefficients
    (Elsevier Ltd., 2013) Atılgan Büyükaşık, Şirin; Pashaev, Oktay
    In this paper, we consider a forced Burgers equation with time variable coefficients of the form Ut+(μ̇(t)/μ(t))U+UUx=(1/2μ(t))Uxx-ω2(t)x, and obtain an explicit solution of the general initial value problem in terms of a corresponding second order linear ordinary differential equation. Special exact solutions such as generalized shock and multi-shock waves, triangular wave, N-wave and rational type solutions are found and discussed. Then, we introduce forced Burgers equations with constant damping and an exponentially decaying diffusion coefficient as exactly solvable models. Different type of exact solutions are obtained for the critical, over and under damping cases, and their behavior is illustrated explicitly. In particular, the existence of inelastic type of collisions is observed by constructing multi-shock wave solutions, and for the rational type solutions the motion of the pole singularities is described.
  • Article
    Citation - WoS: 25
    Citation - Scopus: 27
    Some Remarks on Exp-Function Method and Its Applications
    (IOP Publishing Ltd., 2011) Aslan, İsmail; Marinakis, Vangelis
    Recently, many important nonlinear partial differential equations arising in the applied physical and mathematical sciences have been tackled by a popular approach, the so-called Exp-function method. In this paper, we present some shortcomings of this method by analyzing the results of recently published papers. We also discuss the possible improvement of the effectiveness of the method.
  • Article
    Citation - WoS: 25
    Citation - Scopus: 25
    Exact and Explicit Solutions To the Discrete Nonlinear Schrödinger Equation With a Saturable Nonlinearity
    (Elsevier Ltd., 2011) Aslan, İsmail
    We analyze the discrete nonlinear Schrödinger equation with a saturable nonlinearity through the (G′/G)-expansion method to present some improved results. Three types of analytic solutions with arbitrary parameters are constructed; hyperbolic, trigonometric, and rational which have not been explicitly computed before. © 2011 Elsevier B.V. All rights reserved.
  • Conference Object
    Damped Parametric Oscillator and Exactly Solvable Complex Burgers Equations
    (IOP Publishing Ltd., 2012) Atılgan Büyükaşık, Şirin; Pashaev, Oktay
    We obtain exact solutions of a parametric Madelung fluid model with dissipation which is linearazible in the form of Schrödinger equation with time variable coefficients. The corresponding complex Burgers equation is solved by a generalized Cole-Hopf transformation and the dynamics of the pole singularities is described explicitly. In particular, we give exact solutions for variable parametric Madelung fluid and complex Burgers equations related with the Sturm-Liouville problems for the classical Hermite, Laguerre and Legendre type orthogonal polynomials.
  • Article
    Citation - WoS: 77
    Citation - Scopus: 110
    Analytic Study on Two Nonlinear Evolution Equations by Using the (g'/g)-expansion Method
    (Elsevier Ltd., 2009) Aslan, İsmail; Öziş, Turgut
    The validity and reliability of the so-called (G′/G)-expansion method is tested by applying it to two nonlinear evolutionary equations. Solutions in more general forms are obtained. When the parameters are taken as special values, it is observed that the previously known solutions can be recovered. New rational function solutions are also presented. Being concise and less restrictive, the method can be applied to many nonlinear partial differential equations.
  • Article
    Citation - WoS: 9
    Citation - Scopus: 10
    Comment On: "new Exact Solutions for the Kawahara Equation Using Exp-Function Method" [j. Comput. Appl. Math. 233 (2009) 97102]
    (Elsevier Ltd., 2010) Aslan, İsmail
    Assas [Laila M.B. Assas, New exact solutions for the Kawahara equation using Exp-function method, J. Comput. Appl. Math. 233 (2009) 97102] found some supposedly new exact solutions to the Kawahara equation by means of the Exp-function method. Unfortunately, they are incorrect. We emphasize that the article contains erroneous formulas and resulting relations. In fact, no numerical method was used. © 2010 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Madelung Representation of Damped Parametric Quantum Oscillator and Exactly Solvable Schrödinger-Burgers Equations
    (American Institute of Physics, 2010) Atılgan Büyükaşık, Şirin; Pashaev, Oktay
    We construct a Madelung fluid model with time variable parameters as a dissipative quantum fluid and linearize it in terms of Schrödinger equation with time-dependent parameters. It allows us to find exact solutions of the nonlinear Madelung system in terms of solutions of the Schrödinger equation and the corresponding classical linear ordinary differential equation with variable frequency and damping. For the complex velocity field, the Madelung system takes the form of a nonlinear complex Schrödinger-Burgers equation, for which we obtain exact solutions using complex Cole-Hopf transformation. In particular, we give exact results for nonlinear Madelung systems related with Caldirola-Kanai-type dissipative harmonic oscillator. Collapse of the wave function in dissipative models and possible implications for the quantum cosmology are discussed. © 2010 American Institute of Physics.