Ground states for nonlinear fractional Choquard equations with general nonlinearities

We study the existence of ground states for the nonlinear Choquard equation driven by fractional Laplacian: where the nonlinearity satisfies the general Berestycki–Lions‐type assumptions. Copyright © 2016 John Wiley & Sons, Ltd.     

Liouville-type theorem for nonlinear elliptic equations involving p-Laplace–type Grushin operators

In this article, we prove the Liouville-type theorem for stable solutions of weighted p-Laplace–type Grushin equations (1) and (2) where p ≥ 2, q>0 and are nonnegative functions satisfying and as ‖z‖_G ≥ R₀ with p−N_γ<b<θ+p, R₀,C_i(i=1,2) are some positive constants. ∇_G=(∇_x,(1+γ)|x|^γ∇_y),γ ≥ 0, and The results hold true for N_γ<μ₀(p,b,θ) in 1 and q>q_c(p,N_γ,b,θ) in 2 . Here, μ₀ and q_c are new exponents, which are always larger than the classical critical ones and depend on the parameters p,b and θ. N_γ=N₁+(1+γ)N₂ is the homogeneous dimension of      

Existence and multiplicity of normalized solutions for a class of fractional Choquard equations

In this paper, we study the existence and multiplicity of solutions with a prescribed L2-norm for a class of nonlinear fractional Choquard equations in RN:(-△)su-λu =(κα*|u|p)|u|p-2u,where N≥3,s∈(0,1),α∈(0,N),p∈(max{1 +(α+2s)/N,2},(N+α)/(N-2s)) and κα(x)=|x|α-N. To get such solutions,we look for critical points of the energy functional I(u) =1/2∫RN|(-△)s/2u|2-1/(2p)∫RN(κα*|u|p)|u|p on the constraints S(c)={u∈Hs(RN):‖u‖L2(RN)2=c},c >0.For the value p∈(max{1+(α+2s)/N,2},(N+α)/(N-2s)) considered, the functional I is unbounded from below on S(c). By using the constrained minimization method on a suitable submanifold of S(c), we prove that for any c>0, I has a critical point on S(c) with the least energy among all critical points of I restricted on S(c). After that,we describe a limiting behavior of the constrained critical point as c vanishes and tends to infinity. Moreover,by using a minimax procedure, we prove that for any c>0, there are infinitely many radial critical points of I restricted on S(c).     

Liouville-type theorems for nonlinear degenerate parabolic equation

We study Liouville-type theorems for degenerate parabolic equation of the form \({u_t-{\rm div}(|\nabla u|^{m-2}\nabla u) = u^p}\) where \({m > 2}\) and \({p > m - 1}\). We prove the optimal Liouville-type results in dimension \({N = 1}\), and for radial solutions in any dimension. We also provide some partial results for non-radial solutions in dimension \({N \geq 2}\). Our proofs are based on a generalized Gidas–Spruck technique, combined with the idea of Serrin and Zou (Acta Math 189(1):79–142, 2002) and of Bidaut-Véron (Équations aux dérivées partielles et applications. Elsevier, Paris, pp 189–198, 1998). Finally, we clarify and correct some of the previous results on this topic.     

Existence of positive solutions for fractional boundary value problems

In this paper, by introducing a new operator, improving and generating a p-Laplace operator for some $p > 1$, we discuss the existence and multiplicity of positive solutions to the four point boundary value problems of nonlinear fractional differential equations. Our results extend some recent works in the literature.     

Some Liouville-type theorems for harmonic functions on Finsler manifolds

In this paper, we give some Liouville-type theorems for L^p$L^p$(p∈R)$(p\in \mathbb{R})$ harmonic (resp. subharmonic, superharmonic) functions on forward complete Finsler manifolds. Moreover, we derive a gradient estimate for harmonic functions on a closed Finsler manifold. As an application, one obtains that any harmonic function on a closed Finsler manifold with nonnegative weighted Ricci curvature _RicN${\mathit{Ric}}_N$(N∈(n,∞))$(N\in (n,\infty ))$ must be constant.     

Existence and Liouville-type theorems for some indefinite quasilinear elliptic problems with potentials vanishing at infinity

We study the existence versus absence of nontrivial weak solutions for a class of indefinite quasilinear elliptic problems on unbounded domains with noncompact boundary, in the presence of competing lower order nonlinearities with potentials decaying to zero at infinity.     

On a nonlinear distributed order fractional differential equation

We study the existence and the uniqueness of mild and classical solutions for a class of equations of the form . Such equations arise in distributed derivatives models of viscoelasticity and system identification theory. We also formulate a variational principle for a more general equation based on a method of doubling of variables for such equations.     

Extremal solutions for a nonlinear impulsive differential equations with multi-orders fractional derivatives

In this paper, by employing the lower and upper solutions method, we give an existence theorem for the extremal solutions for a nonlinear impulsive differential equations with multi-orders fractional derivatives and integral boundary conditions. A new comparison result is also established.     

Soliton dynamics for the generalized Choquard equation

We investigate the soliton dynamics for a class of nonlinear Schrödinger equations with a non-local nonlinear term. In particular, we consider what we call generalized Choquard equation   where the nonlinear term is (|x|^θ−N?|u|^p)|u|^p−2u$({|x|}^{\theta -N}?{|u|}^p){|u|}^{p-2}u$. This problem is particularly interesting because the ground state solutions are not known to be unique or non-degenerate.     

A Liouville-type theorem for the stationary MHD equations

We establish a new Liouville-type theorem for solutions of the stationary MHD equations imposing asymmetric oscillation growth conditions on the tensor-valued functions for the velocity and the magnetic field.     

对一个非线性分数阶微分方程组爆破解的研究

The paper focuses on the blow-up solution of system of time-fractional differential equations
where ^cD₀₊^α, ^cD₀₊^β are Caputo fractional derivatives, n-1 < α < n, n-1 < β < n,A(t),B(t) are continuous functions. We obtain a system of the integral equations which is equivalent to the system of nonlinear partial differential equations with time-fractional derivative via the approach of Laplace transformation, and prove the local existence of solutions to the system of the integral equations. Secondly, this paper investigates the blow-up solutions to the a nonlinear system of fractional differential equations by making use of Hölder’s inequality and obtains a solution of system to blow up in a finite time, and gives an upper bound on the blow-up time.     

Ground state solutions for a modified fractional Schrödinger equation with critical exponent

In this paper, we study the existence of ground state solutions for the modified fractional Schrödinger equations $${(-\mathrm{\Delta })}^{\alpha }u+\mu u+\kappa [{(-\mathrm{\Delta })}^{\alpha }{u}^2]u=\sigma |u{|}^{p-1}u+|u{|}^{q-2}u,x\in R^N,$$ where $N\ge 2$, $\alpha \in (0,1)$, $\mu$, $\sigma$ and $\kappa$ are positive parameters, $2<p+1<q\le 2_{\alpha }^{\ast }:=\frac{2N}{N-2\alpha }$, ${(-\mathrm{\Delta })}^{\alpha }$ denotes the fractional Laplacian of order $\alpha$. For the case $2<p+1<q<2_{\alpha }^{\ast }$ and the case $q=2_{\alpha }^{\ast }$, the existence results of ground state solutions are given, respectively.