Complete integrability of the Kadomtsev-Petviashvili equation

The total hierarchy of the Kadomtsev-Petviashvili (KP) equation is transformed to the system of linear partial differential equations with constant coefficients. The complete integrability of the KP equation is proved by using this linear system. The existence and uniqueness theorem of the Cauchy problem of the KP hierarchy is obtained.     

Pfaffianization of the generalized variable-coefficient Kadomtsev-Petviashvili equation

In this paper, the pfaffianization procedure is applied to the generalized variable-coefficient Kadomtsev-Petviashvili (vcKP) equation which can describe the realistic nonlinear phenomena in the fluid dynamics and plasmas. Using the pfaffianization procedure, the coupled system for the generalized vcKP equation is derived together with the Wronski-type pfaffian solution for this generalized coupled vcKP system under certain coefficient constraint. Furthermore, the Gramm-type pfaffian solution for such a coupled system is presented and verified by virtue of the pfaffian identities.     

Solitary waves of the generalized Kadomtsev-Petviashvili equations

In this paper, we consider the existence of solitary waves of the generalized Kadomtsev-Petviashvili equations by using variational methods.     

Cauchy problem for the generalized Kadomtsev-Petviashvili equation

Moscow. Translated from Sibirskii Matematicheskii Zhurnal, Vol. 33, No. 1, pp. 160–172, January–February, 1992.     

Recent results on the generalized Kadomtsev-Petviashvili equations

We survey some recent results concerning the generalized Kadomtsev-Petviashvili equations, which are natural extensions of KdV type equations to higher dimensions. We will focus on rigorous results of the Cauchy problem and on the existence and properties of localized solitary waves.     

Explicit and implicit solutions of a generalized Camassa-Holm Kadomtsev-Petviashvili equation

In this paper, a generalized Camassa-Holm Kadomtsev-Petviashvili (gCH-KP) equation is studied. As a result, under different parameter conditions, the bounded travelling wave solutions such as periodic waves, periodic cusp waves, solitary waves, peakons, loops and kink waves are given, and the dynamic characters of these solutions are investigated.     

Blow up and instability of solitary-wave solutions to a generalized Kadomtsev-Petviashvili equation

In this paper we consider a generalized Kadomtsev-Petviashvili equation in the form It is shown that the solutions blow up in finite time for the supercritical power of nonlinearity with the ratio of an even to an odd integer. Moreover, it is shown that the solitary waves are strongly unstable if ; that is, the solutions blow up in finite time provided they start near an unstable solitary wave.     

Meromorphic exact solutions of the generalized (3+1)-dimensional Kadomtsev-Petviashvili equations

In this work, the generalized (3+1)-dimensional Kadomtsev-Petviashvili equation and its new form have been systematically investigated by using the complex method. The method is based on complex analysis and complex differential equations. And we get plentiful meromorphic exact solutions of these equations, which include rational solutions, exponential function solutions, and elliptic function solutions. The dynamic behaviors of these solutions are also shown by some graphs.     

Lump solutions to the generalized (2+1)-dimensional B-type Kadomtsev-Petviashvili equation

Through symbolic computation with Maple, the (2+1)-dimensional B-type Kadomtsev-Petviashvili(BKP) equation is considered. The generalized bilinear form not the Hirota bilinear method is the starting point in the computation process in this paper. The resulting lump solutions contain six free parameters, four of which satisfy two determinant conditions to guarantee the analyticity and rational localization of the solutions, while the others are arbitrary. Finally, the dynamic properties of these solutions are shown in figures by choosing the values of the parameters.     

Uniqueness of generalized p-area minimizers and integrability of a horizontal normal in the Heisenberg group

We study the uniqueness of generalized \(p\) -minimal surfaces in the Heisenberg group. The generalized \(p\) -area of a graph defined by \(u\) reads \(\int |\nabla u+\vec {F}|+Hu.\) If \(u\) and \(v\) are two minimizers for the generalized \(p\) -area satisfying the same Dirichlet boundary condition, then we can only get \(N_{\vec {F}}(u) = N_{\vec {F}}(v)\) (on the nonsingular set) where \(N_{\vec {F}}(w) := \frac{\nabla w+\vec {F}}{|\nabla w+\vec {F}|}.\) To conclude \(u = v\) (or \(\nabla u = \nabla v)\) , it is not straightforward as in the Riemannian case, but requires some special argument in general. In this paper, we prove that \(N_{\vec {F}}(u) = N_{ \vec {F}}(v)\) implies \(\nabla u = \nabla v\) in dimension \(\ge \) 3 under some rank condition on derivatives of \(\vec {F}\) or the nonintegrability condition of contact form associated to \(u\) or \(v\) . Note that in dimension 2 ( \(n=1),\) the above statement is no longer true. Inspired by an equation for the horizontal normal \(N_{\vec {F}}(u),\) we study the integrability for a unit vector to be the horizontal normal of a graph. We find a Codazzi-like equation together with this equation to form an integrability condition.     

A note on the integrability of the classical portfolio selection model

We revisit the classical Merton portfolio selection model from the perspective of integrability analysis. By an application of a nonlocal transformation the nonlinear partial differential equation for the two-asset model is mapped into a linear option valuation equation with a consumption dependent source term. This result is identical to the one obtained by Cox–Huang [J.C. Cox, C.-f. Huang, Optimal consumption and portfolio policies when asset prices follow a diffusion process, J. Econom. Theory 49 (1989) 33–88], using measure theory and stochastic integrals. The nonlinear two-asset equation is then analyzed using the theory of Lie symmetry groups. We show that the linearization is directly related to the structure of the generalized symmetries.     

Trudinger's exponential integrability for Riesz potentials of functions in generalized grand Morrey spaces

Our aim in this paper is to discuss Trudinger's exponential integrability for Riesz potentials of functions in generalized grand Morrey spaces. Our result will imply the boundedness of the Riesz potential operator from a grand Morrey space to a Morrey space.     

The lie group and integrability of the Fisher type travelling wave equation

For the Fisher-type wave equation, which has two stable states and one unstable state, it is proved that only in two particular cases, the corresponding travelling wave equation admits a double parameter Lie group, and based on a method different to the traditional one, its two independent first integrals are given. It is proved further that in the two integrable cases, the different bounded and non-trivial travelling wave solutions, which are corresponding the invariant manifolds of the corresponding equation under the Lie transformation, can be expressed with elementary functions although they cannot be obtained directly from the two independent first integrals.