共查询到20条相似文献,搜索用时 46 毫秒
1.
Andrea Pascucci 《Transactions of the American Mathematical Society》2003,355(3):901-924
We study the interior regularity properties of the solutions to the degenerate parabolic equation,
which arises in mathematical finance and in the theory of diffusion processes.
which arises in mathematical finance and in the theory of diffusion processes.
2.
Lorenzo D'Ambrosio Enzo Mitidieri Stanislav I. Pohozaev 《Transactions of the American Mathematical Society》2006,358(2):893-910
Let be a possibly degenerate second order differential operator and let be its fundamental solution at ; here is a suitable distance. In this paper we study necessary and sufficient conditions for the weak solutions of on to satisfy the representation formula
then (R) holds with no growth assumptions on .
We prove that (R) holds provided is superlinear, without any assumption on the behavior of at infinity. On the other hand, if satisfies the condition
then (R) holds with no growth assumptions on .
3.
Luis Caffarelli Arshak Petrosyan Henrik Shahgholian 《Journal of the American Mathematical Society》2004,17(4):827-869
We study the regularity of the free boundary in a Stefan-type problem
with no sign assumptions on and the time derivative .
with no sign assumptions on and the time derivative .
4.
Daniel C. Biles Eric Schechter 《Proceedings of the American Mathematical Society》2000,128(11):3349-3360
This paper proves the existence of solutions to the initial value problem
where may be discontinuous but is assumed to satisfy conditions of superposition-measurability, quasimonotonicity, quasisemicontinuity, and integrability. The set can be arbitrarily large (finite or infinite); our theorem is new even for . The proof is based partly on measure-theoretic techniques used in one dimension under slightly stronger hypotheses by Rzymowski and Walachowski. Further generalizations are mentioned at the end of the paper.
5.
D. G. De Figueiredo Y. H. Ding 《Transactions of the American Mathematical Society》2003,355(7):2973-2989
We study existence and multiplicity of solutions of the elliptic system
where , is a smooth bounded domain and . We assume that the nonlinear term
where , , and . So some supercritical systems are included. Nontrivial solutions are obtained. When is even in , we show that the system possesses a sequence of solutions associated with a sequence of positive energies (resp. negative energies) going toward infinity (resp. zero) if 2$"> (resp. ). All results are proved using variational methods. Some new critical point theorems for strongly indefinite functionals are proved.
where , is a smooth bounded domain and . We assume that the nonlinear term
where , , and . So some supercritical systems are included. Nontrivial solutions are obtained. When is even in , we show that the system possesses a sequence of solutions associated with a sequence of positive energies (resp. negative energies) going toward infinity (resp. zero) if 2$"> (resp. ). All results are proved using variational methods. Some new critical point theorems for strongly indefinite functionals are proved.
6.
Gao-Feng Zheng 《Proceedings of the American Mathematical Society》2007,135(5):1487-1494
Results on finite-time blow-up of solutions to the nonlocal parabolic problem are established. They extend some known results to higher dimensions.
7.
S. Prashanth 《Proceedings of the American Mathematical Society》2007,135(1):201-209
Let denote the closure of in the norm Let and define the constants and Let We consider the following problem for We show an exact multiplicity result for for all small .
8.
Norimichi Hirano Naoki Shioji 《Proceedings of the American Mathematical Society》2006,134(9):2585-2592
Let , let and let be a bounded domain with a smooth boundary . Our purpose in this paper is to consider the existence of solutions of the problem: where
9.
Multiple symmetric positive solutions of a class of boundary value problems for higher order ordinary differential equations 总被引:3,自引:0,他引:3
John R. Graef Chuanxi Qian Bo Yang 《Proceedings of the American Mathematical Society》2003,131(2):577-585
In this paper, the authors consider the boundary value problem
and give sufficient conditions for the existence of any number of symmetric positive solutions of (E)-(B). The relationships between the results in this paper and some recent work by Henderson and Thompson (Proc. Amer. Math. Soc. 128 (2000), 2373-2379) are discussed.
and give sufficient conditions for the existence of any number of symmetric positive solutions of (E)-(B). The relationships between the results in this paper and some recent work by Henderson and Thompson (Proc. Amer. Math. Soc. 128 (2000), 2373-2379) are discussed.
10.
Ismail Kombe 《Proceedings of the American Mathematical Society》2004,132(9):2683-2691
In this paper we consider the following initial value problem:
where and . Nonexistence of positive solutions is analyzed.
where and . Nonexistence of positive solutions is analyzed.
11.
Jean Dolbeault Isabel Flores 《Transactions of the American Mathematical Society》2007,359(9):4073-4087
We consider the problem where denotes the unit ball in , , and . Merle and Peletier showed that for there is a unique value such that a radial singular solution exists. This value is the only one at which an unbounded sequence of classical solutions of (1) may accumulate. Here we prove that if additionally then for close to , a large number of classical solutions of (1) exist. In particular infinitely many solutions are present if . We establish a similar assertion for the problem where , , and satisfies the same condition as above.
12.
Yanheng Ding Cheng Lee Fukun Zhao 《Calculus of Variations and Partial Differential Equations》2014,51(3-4):725-760
This paper is concerned with the existence and concentration properties of the ground state solutions to the following coupled Schrödinger systems $$\begin{aligned} \left\{ \begin{array}{l} -\varepsilon ^2\varDelta u+u+V(x)v=W(x)G_{v}(z)~\hbox { in }\ {\mathbb {R}}^N,\\ -\varepsilon ^2\varDelta v+v+V(x)u=W(x)G_{u}(z)~\hbox {in } \ {\mathbb {R}}^N,\\ u(x)\rightarrow 0\ \hbox {and }v(x)\rightarrow 0\ \hbox {as } \ |x|\rightarrow \infty , \end{array} \right. \end{aligned}$$ and $$\begin{aligned} \left\{ \begin{array}{l} -\varepsilon ^2\varDelta u+u+V(x)v=W(x)(G_{v}(z)+|z|^{2^*-2}v)~\hbox {in } \ {\mathbb {R}}^N,\\ -\varepsilon ^2\varDelta v+v+V(x)u=W(x)(G_{u}(z)+|z|^{2^*-2}u)~\hbox {in } \ {\mathbb {R}}^N,\\ u(x)\rightarrow 0\ \hbox {and }v(x)\rightarrow 0\ \hbox {as } \ |x|\rightarrow \infty , \end{array} \right. \end{aligned}$$ where \(z=(u,v)\in {\mathbb {R}}^2\) , \(G\) is a power type nonlinearity, having superquadratic growth at both \(0\) and infinity but subcritical, \(V\) can be sign-changing and \(\inf W>0\) . We prove the existence, exponential decay, \(H^2\) -convergence and concentration phenomena of the ground state solutions for small \(\varepsilon >0\) . 相似文献
13.
Miroslav Pavlovic 《Proceedings of the American Mathematical Society》2006,134(12):3625-3627
A very short proof is given of the inequality where and is the Poisson integral of
14.
Yun-guang Lu Christian Klingenberg 《Proceedings of the American Mathematical Society》2004,132(5):1305-1309
To a given system of conservation laws
we associate the system
which is of mixed type. Under certain conditions, convergence of this latter system for with is established without the need of stability criteria or hyperbolicity of the left-hand sides of the equations.
we associate the system
which is of mixed type. Under certain conditions, convergence of this latter system for with is established without the need of stability criteria or hyperbolicity of the left-hand sides of the equations.
15.
The quartile operator and pointwise convergence of Walsh series 总被引:3,自引:0,他引:3
Christoph Thiele 《Transactions of the American Mathematical Society》2000,352(12):5745-5766
The bilinear Hilbert transform is given by
It satisfies estimates of the type
In this paper we prove such estimates for a discrete model of the bilinear Hilbert transform involving the Walsh Fourier transform. We also reprove the well-known fact that the Walsh Fourier series of a function in , with converges pointwise almost everywhere. The purpose of this exposition is to clarify the connection between these two results and to present an easy approach to recent methods of time-frequency analysis.
16.
Ali Taheri 《Proceedings of the American Mathematical Society》2003,131(10):3101-3107
Let be a bounded starshaped domain. In this note we consider critical points of the functional
where of class satisfies the natural growth
for some and 0$">, is suitably rank-one convex and in addition is strictly quasiconvex at . We establish uniqueness results under the extra assumption that is stationary at with respect to variations of the domain. These statements should be compared to the uniqueness result of Knops & Stuart (1984) in the smooth case and recent counterexamples to regularity produced by Müller & Sverák (2003).
where of class satisfies the natural growth
for some and 0$">, is suitably rank-one convex and in addition is strictly quasiconvex at . We establish uniqueness results under the extra assumption that is stationary at with respect to variations of the domain. These statements should be compared to the uniqueness result of Knops & Stuart (1984) in the smooth case and recent counterexamples to regularity produced by Müller & Sverák (2003).
17.
On a Liouville-type theorem and the Fujita blow-up phenomenon 总被引:3,自引:0,他引:3
The main purpose of this paper is to obtain the well-known results of H.Fujita and K.Hayakawa on the nonexistence of nontrivial nonnegative global solutions for the Cauchy problem for the equation
with on the half-space as a consequence of a new Liouville theorem of elliptic type for solutions of () on . This new result is in turn a consequence of other new phenomena established for nonlinear evolution problems. In particular, we prove that the inequality
has no nontrivial solutions on when We also show that the inequality
has no nontrivial nonnegative solutions for , and it has no solutions on bounded below by a positive constant for 1.$">
with on the half-space as a consequence of a new Liouville theorem of elliptic type for solutions of () on . This new result is in turn a consequence of other new phenomena established for nonlinear evolution problems. In particular, we prove that the inequality
has no nontrivial solutions on when We also show that the inequality
has no nontrivial nonnegative solutions for , and it has no solutions on bounded below by a positive constant for 1.$">
18.
Chunlei Liu 《Proceedings of the American Mathematical Society》2002,130(7):1887-1892
Let be a nontrivial Dirichlet character modulo an odd prime . Write
We shall prove
and, for complex ,
where is a constant depending only on .
We shall prove
and, for complex ,
0, \end{displaymath}">
where is a constant depending only on .
19.
We consider an equation
where , and By a solution of equation (1), we mean any function such that and equality (1) holds almost everywhere on In this paper, we obtain a criterion for the correct solvability of (1) in ,
where , and By a solution of equation (1), we mean any function such that and equality (1) holds almost everywhere on In this paper, we obtain a criterion for the correct solvability of (1) in ,
20.
By using Krasnoselskii's fixed point theorem, we prove that the following periodic species Lotka-Volterra competition system with multiple deviating arguments has at least one positive periodic solution provided that the corresponding system of linear equations has a positive solution, where and are periodic functions with Furthermore, when and , , are constants but , remain -periodic, we show that the condition on is also necessary for to have at least one positive periodic solution.