Nonlinear Sobolev-type Equations Research Articles

Painleve analysis of travelling wave solutions and analysis of energy estimates for a nonlinear Sobolev-type equation

Painleve analysis of travelling wave solutions and analysis of energy estimates for a nonlinear Sobolev-type equation

Extraction of soliton for the confirmable time-fractional nonlinear Sobolev-type equations in semiconductor by [formula omitted]-modal expansion method

The current study deals with the exact solutions of nonlinear confirmable time fractional Sobolev type equations. Such equations have applications in thermodynamics, the flow of fluid through fractured rock. The underlying models are 2D equation of a semi-conductor with heating and Sobolev equation in 2D unbounded domain. These equation are used to describe the different aspects in semi-conductor. The analytical solutions of underlying models is not addressed yet or it is difficult to find. We gain the exact solutions of such models with help of analytical technique namely ϕ6-model expansion method. The abundant families of solutions are obtained by the Jacobi elliptic function and it will give us soliton and solitary wave solutions. So, we extract the different types of solutions such as, dark, bright, singular, combine, periodic and mixed periodic. The unique physical problems are selected from a variety of the solutions that will help the reader for the verification and data experiment. The graphical behavior of the underlying models is represented in the form of 3D, line graphs and their corresponding contours for the various values of the parameters.

Logarithmic nature of the long-time asymptotics of solutions of a Sobolev-type nonlinear equations with cubic nonlinearities

The Cauchy problem of the form $$ \begin{cases} i \partial_{t}(u-\partial_{x}^{2}u)+\partial_{x}^{2}u -a \partial_{x}^{4}u=u^{3}, & t>0, x\in\mathbb{R}, u(0,x) =u_{0}(x),& x\in\mathbb{R}, \end{cases} $$ is considered for a Sobolev-type nonlinear equation with cubic nonlinearity, where $a>1/5$, $a\neq1$. It is shown that the asymptotic behaviour of the solution is characterized by an additional logarithmic decay in comparison with the corresponding linear case. To find the asymptotics of solutions of the Cauchy problem for a nonlinear Sobolev-type equation, factorization technique is developed. To obtain estimates for derivatives of the defect operators, $\mathbf{L}^{2}$-estimates of pseudodifferential operators are used. Bibliography: 20 titles.

Instantaneous blow-up for nonlinear Sobolev type equations with potentials on Riemannian manifolds

<p style='text-indent:20px;'>We investigate Cauchy problems for two classes of nonlinear Sobolev type equations with potentials defined on complete noncompact Riemannian manifolds. The first one involves a polynomial nonlinearity and the second one involves a gradient nonlinearity. Namely, we derive sufficient conditions depending on the geometry of the manifold, the power nonlinearity, the behavior of the potential at infinity, and the initial data, for which the considered problems admit no nontrivial local weak solutions, i.e., an instantaneous blow-up occurs.</p>

On exact solutions of a Sobolev equation

A nonlinear Sobolev-type equation that can be used to describe nonstationary processes in the semiconductor medium is studied. A number of families of exact solutions of this equation that can be expressed in terms of elementary functions and quadratures is obtained; some of these families contain arbitrary sufficiently smooth functions of one argument. The qualitative behavior of the resulting solutions is analyzed.

Разрушение решения уравнения стратификации объемного заряда в полупроводниках: численный анализ при сведении исходного уравнения к дифференциально-алгебраической системе

Показана эффективность одной из методик численной диагностики разрушения решения на примере решения нелинейного уравнения cоболевского типа, описывающего стратификацию объемного заряда в полупроводниках. В процессе численного исследования этой задачи использовался подход, основанный на сведении исходного уравнения в частных производных к дифференциально-алгебраической системе с последующим решением этой системы с помощью одностадийной схемы Розенброка с комплексным коэффициентом. Численная диагностика разрушения точного решения указанного уравнения основывалась на методике вычисления апостериорной асимптотически точной оценки погрешности, получаемой при вычислении приближенного решения на последовательно сгущающихся сетках. The efficiency of one of the methods for the numerical diagnostics of solution's blow-up is shown using the example of solving a nonlinear Sobolev-type equation that describes a space charge stratification in semiconductors. An approach to reduce the original partial differential equation to a differential-algebraic system is used. This system is solved by the Rosenbrock scheme with a complex coefficient. The numerical diagnostics of solution's blow-up is based on the Richardson extrapolation procedure.

On the Cauchy problem for a nonlinear Sobolev type equation

We study the large-time asymptotics of the solution of the Cauchy problem for a nonlinear Sobolev type equation. We show that if initial data are sufficiently small in some norm, then the leading term of the asymptotic expansion is determined by the linear part of the equation and has exponential character, while the nonlinearity affects the decay order of the remainder.

Mixed boundary value problem for a class of strongly nonlinear Sobolev-type equations of higher order

Mixed boundary value problem for a class of strongly nonlinear Sobolev-type equations of higher order

Asymptotic expansion of solutions to the periodic problem for a non-linear Sobolev-type equation

We study the long-time behaviour of solutions to the periodic problem for a non-linear Sobolev-type equation. In the case of non-small initial perturbations we get estimates for the decay as a function of time. In the case of small initial data we prove an asymptotic formula for solutions to the periodic problem for a non-linear Sobolev-type equation.

Blow-up of solutions of an inhomogeneous system of Sobolev-type equations

We consider a system of two inhomogeneous non-linear Sobolev-type equations of order 6 with second derivative with respect to the time variable. We prove that the problem is soluble locally in time, state sufficient conditions for blow-up of a solution at finite time, and give an upper bound for the blow-up time.

On the initial boundary-value problem for a nonlinear Sobolev-type equation with variable coefficient

We study the initial boundary-value problem for a nonlinear Sobolev-type equation with variable coefficient. We obtain sufficient conditions for both global and local (in time) solvability. In the case of local (but not global) solvability, we obtain upper and lower bounds for the existence time of the solution in the form of explicit and quadrature formulas.

Blow-up of the solution of an inhomogeneous system of Sobolev-type equations

We consider a model system of two inhomogeneous nonlinear Sobolev-type equations of sixth order with second-order time derivative and prove the local (with respect to time) solvability of the problem. We state conditions under which the blow-up of the solution occurs in finite time and find an upper bound for the blow-up time.

On sufficient conditions of blowing‐up of solution of initial‐boundary‐value problem for strongly nonlinear Sobolev type equation

AbstractWe consider the initial‐boundary‐value problem for the N‐dimensional, Sobolev‐type equation with source. Under some conditions, the theorems on blowup of solutions at finite time of this problem are obtained. Twosided estimates for blowing‐up time are derived.

Periodic boundary value problem for nonlinear Sobolev-type equations

The large-time asymptotic behavior of solutions to the periodic boundary value problem for a nonlinear Sobolev-type equation is studied. In particular, the case where the initial perturbations are not small is considered. In this case, the large-time behavior of solutions is dichotomous.

Study of the classical solution to the one-dimensional mixed problem for a class of semilinear long-wave equations

Many problems in mathematical physics are reduced to one- or multidimensional initial and initial-boundary value problems for, generally speaking, strongly nonlinear Sobolev-type equations. In this work, local and global classical solvability is studied for the one-dimensional mixed problem with homogeneous Riquier-type boundary conditions for a class of semilinear long-wave equations $$ U_{tt} \left( {t,x} \right) - U_{xx} \left( {t,x} \right) - \alpha U_{ttxx} \left( {t,x} \right) = F\left( {t,x,U\left( {t,x} \right),U_x \left( {t,x} \right),U_{xx} \left( {t,x} \right),U_t \left( {t,x} \right),U_{tx} \left( {t,x} \right),U_{txx} \left( {t,x} \right)} \right) $$ , where α > 0 is a fixed number, 0 ≤ t ≤ T, 0 ≤ x ≤ π, 0 < T < +∞, F is a given function, and U(t, x) is the sought function. A uniqueness theorem for the mixed problem is proved using the Gronwall-Bellman inequality. A local existence result is proved by applying the generalized contraction mapping principle combined with the Schauder fixed point theorem. The method of a priori estimates is used to prove the global existence of a classical solution to the mixed problem.

Large-time asymptotics of the solution of the Cauchy problem for a Sobolev-type equation with a cubic nonlinearity

We consider the asymptotic behavior of the solution of the Cauchy problem for a nonlinear Sobolev-type equation at large times. Such an equation describes the pressure of a fluid in a porous medium or a potential in a semiconductor. We develop ideas used for the investigation of classical and Sobolev equations. In particular, we show that the linear term influences the qualitative behavior of the solution, while the derivatives of the third power of the solution do not.

On the global existence of solution to one-dimensional fourth order nonlinear Sobolev type equations

We prove the global existence and uniqueness of a classical solution to initial boundary value problem for a class of Sobolev type equations under the Dirichlet boundary conditions. This class of evolution equations covers the well-known viscous Cahn–Hilliard equation and the viscous Camassa–Holm equation.

Blow-up of solutions of nonlinear Sobolev type equations with cubic sources

Blow-up of solutions of nonlinear Sobolev type equations with cubic sources

On a nonlinear Sobolev type equation

On a nonlinear Sobolev type equation