共查询到20条相似文献,搜索用时 31 毫秒
1.
Marcello Lucia 《Calculus of Variations and Partial Differential Equations》2006,26(3):313-330
We consider the equation
If Ω is of class C
2, we show that this problem has a non-trivial solution u
λ for each λ ∊ (8 π, λ*). The value λ* depends on the domain and is bounded from below by 2 j
0
2 π, where j
0 is the first zero of the Bessel function of the first kind of order zero (λ*≥ 2 j
0
2 π > 8 π). Moreover, the family of solution u
λ blows-up as λ → 8 π. 相似文献
2.
A. M. Sedletskii 《Journal of Mathematical Sciences》2008,155(1):170-182
Some conditions on sequences (λ
n
) and (μ
n
) to be nearby are given in order that the corresponding systems of complex exponentials (exp(iλ
n
t)) and (exp(iμ
n
t)) be simultaneously uniformly minimal in L
p
(−π, π), 1 ≤ p < ∞, and in C[−π, π].
__________
Translated from Sovremennaya Matematika. Fundamental'nye Napravleniya (Contemporary Mathematics. Fundamental Directions),
Vol. 25, Theory of Functions, 2007. 相似文献
3.
L. Erbe 《Annali di Matematica Pura ed Applicata》1972,94(1):257-268
Summary Various sufficient conditions are obtained which guarantee that all continuable solutions of (1.1) y″+q(t)y′+p(t)f(y)=0 are
oscillatory. No explicit sign assumptions are made on p(t) although certain integral conditions are assumed to hold with regard
to f(y), p(t) and q(t). Examples are given of the form p(t) = λ/tμ + (βsint)/tα, λ, β, μ, α>0.
This research was supported by NRC Grant A-7673 and CMC Summer Research Grant.
Entrata in Redazione il 4 settembre 1971. 相似文献
4.
We study the spectral probleml(u)=−u″+q(x)u(x)=λu(x),u′(0)=0, u′(π)=mλu(π), where λ andm are a spectral and a physical parameter. Form<0, we associate with the problem a self-adjoint operator in Pontryagin space II1. Using this fact and developing analytic methods of the theory of Sturm-Liouville operators, we study the dynamics of eigenvalues
and eigenfunctions of the problems asm→−0.
Translated fromMatematicheskie Zametki, Vol. 66, No. 2, pp. 163–172, August, 1999. 相似文献
5.
Solution of the spectral problem for the curl and Stokes operators with periodic boundary conditions
R. S. Saks 《Journal of Mathematical Sciences》2006,136(2):3794-3811
In this paper, we establish relations between eigenvalues and eigenfunctions of the curl operator and Stokes operator (with
periodic boundary conditions). These relations show that the curl operator is the square root of the Stokes operator with
ν = 1. The multiplicity of the zero eigenvalue of the curl operator is infinite. The space L
2(Q, 2π) is decomposed into a direct sum of eigenspaces of the operator curl. For any complex number λ, the equation rot
u + λu = f and the Stokes equation −ν(Δv + λ 2v) + ∇p = f, div v = 0, are solved. Bibliography: 15 titles.
Dedicated to the memory of Olga Aleksandrovna Ladyzhenskaya
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 318, 2004, pp. 246–276. 相似文献
6.
M. I. Gvaradze 《Mathematical Notes》1977,21(2):79-84
The spacesb (p, q, λ) (0<p<q⩽∞, 0<λ⩽∞) of functions, analytic in the circle |z|< 1, are introduced, and an unimprovable estimate is obtained for the Taylor coefficients
of a functionf∃
b (p, q, λ). It is shown that B(p, q, λ) is the space of fractional derivatives f(α) of order α (−∞<α<1/p−1/q) of a function
f of B(s, q, λ), where s=p/(1−αp).
Translated from Matematicheskie Zametki, Vol. 21, No. 2, pp. 141–150, February, 1977. 相似文献
7.
A. A. Panov 《Mathematical Notes》1977,21(1):22-28
The number Kp,q, i.e., the number of (p, q) corridors of closed domains which are convex in the vertical direction, consist of elementary
squares of the integral lattice, are situated within a rectangle of the size q × p, and completely cover the side of length
p of this rectangle under projection is computed. The asymptotic (Kp,q/q2)1/p → λ, as p, q → ∞, where λ = 0.3644255… is the maximum root of the equation1F1(-1/2 − 1/(16λ), 1/2, 1/(4λ)) = 0,1F1 being the confluence hypergeometric function, is established. These results allow us to compute the ε entropy of the space
of continuous functions with the Hausdorff metric.
Translated from Matematicheskie Zametki, Vol. 21, No. 1, pp. 39–50, January, 1977. 相似文献
8.
We study the semiflow defined by a semilinear parabolic equation with a singular square potential . It is known that the Hardy-Poincaré inequality and its improved versions, have a prominent role on the definition of the
natural phase space. Our study concerns the case 0 < μ ≤ μ*, where μ* is the optimal constant for the Hardy-Poincaré inequality. On a bounded domain of , we justify the global bifurcation of nontrivial equilibrium solutions for a reaction term f(s) = λs − |s|2γ
s, with λ as a bifurcation parameter. We remark some qualitative differences of the branches in the subcritical case μ < μ* and the critical case μ = μ*. The global bifurcation result is used to show that any solution , initiating form initial data tends to the unique nonnegative equilibrium. 相似文献
9.
A. M. Nikitin 《Journal of Mathematical Sciences》1996,80(3):1818-1828
We give an estimate for the spectrum of the averaging operator T1(Γ, 1) over the radius 1 for the finite (q+1)-homogeneous quotient graph Γ/X, where X is an infinite (q+1)-homogeneous tree
associated with the free group G over a finite set of generators S={x1 ..., xp} (2p=q+1), and Γ, a subgroup of finite index in G. T1(Γ, 1) is defined on the subspace L2(Γ/G, 1) ⊖ Eex, where Eex is the subspace of eigenfunctions of T1(Γ, 1) with eigenvalue λ such that |λ|=q+1. We present a construction of some finite homogeneous graphs such that the spectrum
of their adjacency matrices can be calculated explicitly. Bibliography: 11 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 205, 1993, pp. 92–109.
Translated by A. M. Nikitin. 相似文献
10.
Meng Wang 《数学学报(英文版)》2012,28(1):145-170
We study the self-dual Chern-Simons Higgs equation on a compact Riemann surface with the Neumann boundary condition.In the previous paper,we show that the Chern-Simons Higgs equation with parameter λ0 has at least two solutions(uλ1,uλ2) for λ sufficiently large,which satisfy that uλ1→u0 almost everywhere as λ→∞,and that uλ2→∞ almost everywhere as λ→∞,where u 0 is a(negative) Green function on M.In this paper,we study the asymptotic behavior of the solutions as λ→∞,and prove that uλ2-uλ2 converges to a solution of the Kazdan-Warner equation if the geodesic curvature of the boundary M is negative,or the geodesic curvature is nonpositive and the Gauss curvature is negative where the geodesic curvature is zero. 相似文献
11.
In this paper, a necessary and sufficient condition of A(a)-acceptability for rational approximations to the functionexp(q) and some sufficient conditions to guarantee A(α)-acceptability of Padé approximations[^(R)]mn (q)\hat R_m^n (q) to the functionexp(q) are given, where a ∈(0,π/2), n≤m,m≥2. Furthermore, it is proved that the condition of A(α)-acceptability of rational approximations toexp(q) is equivalent to the nonnegatively of a real polynomial in interval (−∞,0). Finally, we prove that[^(R)]41 (q)\hat R_4^1 (q) is A(π/3)-acceptable. Based on this conclusion, two A(π/3)-stable multiderivative (hybrid) one-step methods are constructed. 相似文献
12.
J. García-Melián C. Morales-Rodrigo J. D. Rossi A. Suárez 《Annali di Matematica Pura ed Applicata》2008,187(3):459-486
In this paper we perform an extensive study of the existence, uniqueness (or multiplicity) and stability of nonnegative solutions
to the semilinear elliptic equation − Δu = λ u − u
p
in Ω, with the nonlinear boundary condition ∂u/∂ν = u
r
on ∂Ω. Here Ω is a smooth bounded domain of with outward unit normal ν, λ is a real parameter and p, r > 0. We also give the precise behavior of solutions for large |λ| in the cases where they exist. The proofs are mainly
based on bifurcation techniques, sub-supersolutions and variational methods.
相似文献
13.
Onur Yavuz 《Integral Equations and Operator Theory》2007,58(3):433-446
We consider a multiply connected domain
where
denotes the unit disk and
denotes the closed disk centered at
with radius r
j
for j = 1, . . . , n. We show that if T is a bounded linear operator on a Banach space X whose spectrum contains ∂Ω and does not contain the points λ1, λ2, . . . , λ
n
, and the operators T and r
j
(T − λ
j
I)−1 are polynomially bounded, then there exists a nontrivial common invariant subspace for T
* and (T − λ
j
I)*-1. 相似文献
14.
Mihail N. Kolountzakis 《Journal of Fourier Analysis and Applications》2012,18(1):21-26
A set Ω, of Lebesgue measure 1, in the real line is called spectral if there is a set Λ of real numbers such that the exponential
functions e
λ
(x)=exp (2πiλx), λ∈Λ, form a complete orthonormal system on L
2(Ω). Such a set Λ is called a spectrum of Ω. In this note we present a simplified proof of the fact that any spectrum Λ of
a set Ω which is finite union of intervals must be periodic. The original proof is due to Bose and Madan. 相似文献
15.
S. H. Saker 《Acta Mathematica Hungarica》2003,100(1-2):37-62
We present new oscillation criteria for the second order nonlinear neutral delay differential equation [y(t)-py(t-τ)]'+ q(t)y
λ
(g(t)) sgn y(g(t)) = 0, t ≧ t
0. Our results solve an open problem posed by James S.W . Wong [24]. The relevance of our results becomes clear due to a carefully
selected example.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
16.
In this paper, we consider a nonlinear elliptic equation driven by the p-Laplacian and with a parameter λ > 0. Using a combination of variational and degree theoretic methods, we show that there
exists λ* > 0 such that, if λ > λ*, then the problem has two positive smooth solutions. Our result extends earlier ones by Rabinowitz (semilinear equations)
and Guo (nonlinear equations).
相似文献
17.
Minihypers were introduced by Hamada to investigate linear codes meeting the Griesmer bound. Hamada (Bull Osaka Women’s Univ
24:1–47, 1985; Discrete Math 116:229–268, 1993) characterized the non-weighted minihypers having parameters , with k−1 > λ1 > λ2 > ... > λ
h
≥ 0, as the union of a λ1-dimensional space, λ2-dimensional space, ..., λ
h
-dimensional space, which all are pairwise disjoint. We present in this article a weighted version of this result. We prove
that a weighted -minihyper , with k−1 > λ1 > λ2 > ... > λ
h
≥ 0, is a sum of a λ1-dimensional space, λ2-dimensional space, ..., and λ
h
-dimensional space.
This research was supported by the Project Combined algorithmic and theoretical study of combinatorial structures between the Fund for Scientific Research Flanders-Belgium (FWO-Flanders) and the Bulgarian Academy of Sciences. This research
is also part of the FWO-Flanders project nr. G.0317.06 Linear codes and cryptography. 相似文献
18.
This is a continuation of our previous work. We classify all the simple ℋq(D
n
)-modules via an automorphismh defined on the set { λ | Dλ ≠ 0}. Whenf
n(q) ≠ 0, this yields a classification of all the simple ℋ
q
(D
n)- modules for arbitrary n. In general ( i. e., q arbitrary), if λ(1) = λ(2),wegivea necessary and sufficient condition ( in terms of some polynomials ) to ensure that the irreducible ℋq,1(B
n
)- module Dλ remains irreducible on restriction to ℋq(D
n
). 相似文献
19.
Flávio Dickstein Miguel Loayza 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2008,24(10):1-23
We consider the Cauchy problem for the weakly coupled parabolic system ∂
t
w
λ−Δ w
λ = F(w
λ) in R
N
, where λ > 0, w
λ = (u
λ, v
λ), F(w
λ) = (v
λ
p
, u
λ
q
) for some p, q ≥ 1, pq > 1, and
wl(0) = (lj1, l\fracq+1p+1j2)w_{\lambda}(0) = ({\lambda}{\varphi}_1, {\lambda}^{\frac{q+1}{p+1}}{\varphi}_2), for some nonnegative functions φ1, φ2
?\in
C
0(R
N
). If (p, q) is sub-critical or either φ1 or φ2 has slow decay at ∞, w
λ blows up for all λ > 0. Under these conditions, we study the blowup of w
λ for λ small. 相似文献
20.
Tamar Burak 《Israel Journal of Mathematics》1972,12(1):79-93
Let A be the closed unbounded operator inL
p(G) that is associated with an elliptic boundary value problem for a bounded domainG. We prove the existence of a spectral projectionE determined by the set Γ = {λ;θ
1≦argλ≦θ
2} and show thatAE is the infinitesimal generator of an analytic semigroup provided that the following conditions hold: 1<p<∞; the boundary
ϖΓ of Γ is contained in the resolvent setp(A) ofA;π/2≦θ<θ
2≦3π/2 ; and there exists a constantc such that (I)││(λ-A)-1││≦c/│λ│ for λ∈ϖΓ. The following consequence is obtained: Suppose that there exist constantsM andc such that λ∈p(A) and estimate (I) holds provided that |λ|≧M and Re λ=0. Then there exist bounded projectionE
− andE
+ such thatA is completely reduced by the direct sum decompositionL
p(G)=E−Lp (G) ⊕E+Lp (G) and each of the operatorsAE
− and—AE
+ is the infinitestimal generator of an analytic semigroup. 相似文献