The Nonexistence of Global Solutions for a Time Fractional Schrodinger Equation with Nonlinear Memory

In this paper, we study the nonexistence of solutions of the following time fractional nonlinear Schr?dinger equations with nonlinear memory where 0, ιλ denotes the principal value of ιλ, p>1, T>0, λ∈C/{0}, u(t,x) is a complex-value function, denotes left Riemann-Liouville fractional integrals of order 1-λ and is the Caputo fractional derivative of order . We obtain that the problem admits no global weak solution when and under different conditions for initial data.

Memory effect in time fractional Schrödinger equation

A significant obstacle impeding the advancement of the time fractional Schrodinger equation lies in the challenge of determining its precise mathematical formulation.In order to address this,we undertake an exploration of the time fractional Schrodinger equation within the context of a non-Markovian environment.By leveraging a two-level atom as an illustrative case,we find that the choice to raise i to the order of the time derivative is inappropriate.In contrast to the conventional approach used to depict the dynamic evolution of quantum states in a non-Markovian environment,the time fractional Schrodinger equation,when devoid of fractional-order operations on the imaginary unit i,emerges as a more intuitively comprehensible framework in physics and offers greater simplicity in computational aspects.Meanwhile,we also prove that it is meaningless to study the memory of time fractional Schrodinger equation with time derivative 1<α≤2.It should be noted that we have not yet constructed an open system that can be fully described by the time fractional Schrodinger equation.This will be the focus of future research.Our study might provide a new perspective on the role of time fractional Schrodinger equation.

New existence of multi-spike solutions for the fractional Schrodinger equations

We consider the following fractional Schr¨odinger equation:(-Δ)^(s)u+V(y)u=u^(p);u>0 in R^(N);(0.1)where s ∈(0,1),1<p<N+2s/N-2s,and V(y)is a positive potential function and satisfies some expansion condition at infinity.Under the Lyapunov-Schmidt reduction framework,we construct two kinds of multi-spike solutions for(0.1).The first k-spike solution uk is concentrated at the vertices of the regular k-polygon in the(y1;y2)-plane with k and the radius large enough.Then we show that uk is non-degenerate in our special symmetric workspace,and glue it with an n-spike solution,whose centers lie in another circle in the(y3;y4)-plane,to construct infinitely many multi-spike solutions of new type.The nonlocal property of(-Δ)^(s)is in sharp contrast to the classical Schr¨odinger equations.A striking difference is that although the nonlinear exponent in(0.1)is Sobolev-subcritical,the algebraic(not exponential)decay at infinity of the ground states makes the estimates more subtle and difficult to control.Moreover,due to the non-locality of the fractional operator,we cannot establish the local Pohozaev identities for the solution u directly,but we address its corresponding harmonic extension at the same time.Finally,to construct new solutions we need pointwise estimates of new approximate solutions.To this end,we introduce a special weighted norm,and give the proof in quite a different way.

Entire Sign-Changing Solutions to the Fractional Critical Schrodinger Equation

In this paper,we consider the fractional critical Schrödinger equation(FCSE)(-Δ)^(s)u-|u|2^(*)s-2 u=0,where u∈˙H^(s)(R^(N)),N≥4,0<s<1 and 2^(*)s=2 N/N-2 s is the critical Sobolev exponent of order s.By virtue of the variational method and the concentration compactness principle with the equivariant group action,we obtain some new type of nonradial,sign-changing solutions of(FCSE)in the energy space˙H^(s)(R^(N)).The key component is that we take the equivariant group action to construct several subspace of˙H^(s)(R^(N))with trivial intersection,then combine the concentration compactness argument in the Sobolev space with fractional order to show the compactness property of Palais-Smale sequences in each subspace and obtain the multiple solutions of(FCSE)in˙H^(s)(R^(N)).

Well-Posedness and Blow-Up for the Fractional Schrodinger-Choquard Equation

In this paper,we study the well-posedness and blow-up solutions for the fractional Schrodinger equation with a Hartree-type nonlinearity together with a power-type subcritical or criticai perturbations.For nonradial initial data or radial initial data,we prove the local well-posedness for the defocusing and the focusing cases with sub-critical or critical nonlinearity.We obtain the global well-posedness for the defocusing case,and for the focusing mass-subcritical case or mass-critical case with initial da-ta small enough.We also investigate blow-up solutions for the focusing mass-critical problem.

Infinitely Many Solutions for the Fractional Nonlinear Schrodinger Equations ofa New Type

This paper,we study the multiplicity of solutions for the fractional Schrodingerequation(-△)^(s)u+V(x)u=u^(p),u>0,x∈R^(N),u∈H^(s)(R^(N)),with s∈(0,1),N≥3,p∈(1,2N/N-2s-1)and lim_(|y|→+∞)V(y)>0.By assuming suitable decay property of the radial potential V(y)=V(|y|),we construct another type of solutions concentrating at infinite vertices of two similar equilateral polygonal with infinitely large length of sides.Hence,besides the length of each polygonal,we must consider one more parameter,that is the height of the podetium,simultaneously.Another difficulty lies in the non-local property of the operator(-△)^(s) and the algebraic decay involving the approximation solutions make the estimates become more subtle.

Assorted soliton structures of solutions for fractional nonlinear Schrodinger types evolution equations

Fractional order nonlinear evolution equations have emerged in recent times as being very important model for depicting the interior behavior of nonlinear phenomena that exist in the real world.In particular,Schrodinger-type fractional nonlinear evolution equations constitute an aspect of the field of quantum mechanics.In this study,the(2+1)-dimensional time-fractional nonlinear Schrodinger equation and(1+1)-dimensional time-space fractional nonlinear Schrodinger equation are revealed as having different and novel wave structures.This is shown by constructing appropriate analytic wave solutions.A success-ful implementation of the advised rational(1/φ'(ξ))-expansion method generates new outcomes of the considered equations,by comparing them with those already noted in the literature.On the basis of the conformable fractional derivative,a composite wave variable conversion has been used to adapt the suggested equations into the differential equations with a single independent variable before applying the scheme.Finally,the well-furnished outcomes are plotted in different 3D and 2D profiles for the purpose of illustrating various physical characteristics of wave structures.The employed technique is competent,productive and concise enough,making it feasible for future studies.

Symmetric and antisymmetric vector solitons for the fractional quadric-cubic coupled nonlinear Schrodinger equation

The fractional quadric-cubic coupled nonlinear Schrodinger equation is concerned,and vector symmetric and antisymmetric soliton solutions are obtained by the square operator method.The relationship between the Lévy index and the amplitudes of vector symmetric and antisymmetric solitons is investigated.Two components of vector symmetric and antisymmetric solitons show a positive and negative trend with the Lévy index,respectively.The stability intervals of these solitons and the propagation constants corresponding to the maximum and minimum instability growth rates are studied.Results indicate that vector symmetric solitons are more stable and have better interference resistance than vector antisymmetric solitons.

A conservative numerical method for the fractional nonlinear Schrodinger equation in two dimensions

This paper proposes and analyzes an efficient finite difference scheme for the two-dimensional nonlinear Schr?dinger(NLS) equation involving fractional Laplacian. The scheme is based on a weighted and shifted Grünwald-Letnikov difference(WSGD) operator for the spatial fractional Laplacian. We prove that the proposed method preserves the mass and energy conservation laws in semi-discrete formulations. By introducing the differentiation matrices, the semi-discrete fractional nonlinear Schr?dinger(FNLS) equation can be rewritten as a system of nonlinear ordinary differential equations(ODEs) in matrix formulations. Two kinds of time discretization methods are proposed for the semi-discrete formulation. One is based on the Crank-Nicolson(CN) method which can be proved to preserve the fully discrete mass and energy conservation. The other one is the compact implicit integration factor(c IIF) method which demands much less computational effort. It can be shown that the cIIF scheme can approximate CN scheme with the error O(τ~2). Finally numerical results are presented to demonstrate the method’s conservation, accuracy, efficiency and the capability of capturing blow-up.

Existence of positive solutions with peaks on a Clifford torus for a fractional nonlinear Schrodinger equation

We consider the fractional nonlinear Schr?dinger equation in this paper. Applying the finite reduction method, we prove that the equation has positive solutions with peaks on a Clifford torus under some suitable conditions.

Solutions of Fractional Partial Differential Equations of Quantum Mechanics

The aimof this article is to investigate the solutions of generalized fractional partial differential equations involving Hilfer time fractional derivative and the space fractional generalized Laplace operators,occurring in quantum mechanics.The solutions of these equations are obtained by employing the joint Laplace and Fourier transforms,in terms of the Fox’s H-function.Several special cases as solutions of one dimensional non-homogeneous fractional equations occurring in the quantum mechanics are presented.The results given earlier by Saxena et al.[Fract.Calc.Appl.Anal.,13(2)(2010),pp.177-190]and Purohit and Kalla[J.Phys.AMath.Theor.,44(4)(2011),045202]follow as special cases of our findings.

Standing Waves of Fractional Schrödinger Equations with Potentials and General Nonlinearities

We study the existence of standing waves of fractional Schrodinger equations with a potential term and a general nonlinear term:iut-(-Δ)^(s)u-V(x)u+f(u)=0,(t,x)∈R_(+)×R^(N),where s∈(0,1),N>2s is an integer and V(x)≤0 is radial.More precisely,we investigate the minimizing problem with L2-constraint:E(a)=inf{1/2∫_(R_(N))|(-△)^(s/2)u|^(2)+V(x)|u|^(2)-2F(|u|)|u∈H^(s)(R^(N)),||u||_(L^(2))^(2)(R^(N))=α.Under general assumptions on the nonlinearity term f(u)and the potential term V(x),we prove that there exists a constant a00 such that E(a)can be achieved for all a>a_(0),and there is no global minimizer with respect to E(a)for all 0<a<a_(0).Moreover,we propose some criteria determining a0=0 or a_(0)>0.

A LINEARLY-IMPLICIT ENERGY-PRESERVING ALGORITHM FOR THE TWO-DIMENSIONAL SPACE-FRACTIONAL NONLINEAR SCHRÖDINGER EQUATION BASED ON THE SAV APPROACH

The main objective of this paper is to present an efficient structure-preserving scheme,which is based on the idea of the scalar auxiliary variable approach,for solving the twodimensional space-fractional nonlinear Schrodinger equation.First,we reformulate the equation as an canonical Hamiltonian system,and obtain a new equivalent system via introducing a scalar variable.Then,we construct a semi-discrete energy-preserving scheme by using the Fourier pseudo-spectral method to discretize the equivalent system in space direction.After that,applying the Crank-Nicolson method on the temporal direction gives a linearly-implicit scheme in the fully-discrete version.As expected,the proposed scheme can preserve the energy exactly and more efficient in the sense that only decoupled equations with constant coefficients need to be solved at each time step.Finally,numerical experiments are provided to demonstrate the efficiency and conservation of the scheme.

Numerical Solution of Fractional Partial Differential Equations by Discrete Adomian Decomposition Method

In this paper we find the solution of linear as well as nonlinear fractional partial differential equations using discrete Adomian decomposition method.Here we develop the discrete Adomian decomposition method to find the solution of fractional discrete diffusion equation,nonlinear fractional discrete Schrodinger equation,fractional discrete Ablowitz-Ladik equation and nonlinear fractional discrete Burger’s equation.The obtained solution is verified by comparison with exact solution whenα=1.