共查询到20条相似文献,搜索用时 781 毫秒
1.
Rod Gow 《Geometriae Dedicata》1997,64(3):283-295
Let K be a field of characteristic 2 and letV be a vector space of dimension 2m over K. Let f be a non-degenerate alternating bilinear form defined on V × V. The symplectic group Sp(2m, K) acts on the exterior powers
k
V for 0 k. 2m There is a contraction map defined on the exterior algebra , which commutes with the Sp(2m, K) action and satisfies 2 = 0 and (
k
V)
k–1
V We prove that (
k
V)= ker
k–1
V except when k=m+2. In the exceptional case, (
m+2
V) has codimension 2m in ker
m
V and we show that the quotient module ker
m
V/
m+2
V is a spin module for Sp(2m,K). When K is algebraically closed, we show that this spin module occurs with multiplicity 1 in
m
V and multiplicity 0 in all other components of V. 相似文献
2.
Franco Tomarelli 《Numerische Mathematik》1984,45(1):23-50
Summary We prove some regularity results for the solution of a linear abstract Cauchy problem of parabolic type. As an application, we study the approximation of the solution by means of an implicit-Euler discretization in time, which is stable with respect to a wide class of Galerkin approximation methods in space. The error is evaluated in norms of typeL
2(0, ,L
2) andL
2(0, ,V)(H
00
1/2
(0, ,H)+H
1(0, ,V)), whereVHV are Hilbert spaces (the embeddings are supposed to be dense and continuous). We prove error estimates which are optimal with respect to the regularity assumptions on the right-hand side of the equation.The author was supported by G.N.A.F.A. and I.A.N. of C.N.R. and by M.P.I. 相似文献
3.
V. A. Slousch 《Journal of Mathematical Sciences》2003,115(2):2272-2278
Let A be a self-adjoint elliptic second-order differential operator, let (, ) be an inner gap in the spectrum of A, and let B(t) = A + tW
*
W, where W is a differential operator of higher order. Conditions are obtained under which the spectrum of the operator B(t) in the gap (, ) is either discrete, or does not accumulate to the right-hand boundary of the spectral gap, or is finite. The quantity N(, A, W, ), (, ), > 0 (the number of eigenvalues of the operator B(t) passing the point (, ) as t increases from 0 to ) is considered. Estimates of N(, A, W, ) are obtained. For the perturbation W
*
W of a special form, the asymptotics of N(, A, W, ) as + is given. Bibliography: 5 titles. 相似文献
4.
We prove a local limit theorem (LLT) on Cramer-type large deviations for sums S
V
=
t
V (
t
), where
t
, t Z
, 1, is a Markov Gaussian random field, V Z
, and is a bounded Borel function. We get an estimate from below for the variance of S
V
and construct two classes of functions , for which the LLT of large deviations holds. 相似文献
5.
Summary LetC be the symmetric cusp {(x, y)2:–x
yx
,x0} where >1. In this paper we decide whether or not reflecting Brownian motion inC has a semimartingale representation. Here the reflecting Brownian motion has directions of reflection that make constant angles with the unit inward normals to the boundary. Our results carry through for a wide class of asymmetric cusps too. 相似文献
6.
On a bounded C
2-domain
we consider the singular boundary-value problem 1/2u=f(u) in D, u
D
=, where d3, f:(0,)(0,) is a locally Hölder continuous function such that f(u) as u0 at the rate u
–, for some (0,1), and is a non-negative continuous function satisfying certain growth assumptions. We show existence of solutions bounded below by a positive harmonic function, which are smooth in D and continuous in
. Such solutions are shown to satisfy a boundary Harnack principle. 相似文献
7.
B. Barabás 《Periodica Mathematica Hungarica》1987,18(2):115-122
The properties of the empirical density function,f
n(x) = k/n(
j
+
–
j-1
+
) if
j-1
+
< x + where
j-1
+
and
j
+
are sample elements and there are exactlyk – 1 sample elements between them, are studied in that practical point of view how to choose a suitablek for a good estimation. A bound is given for the expected value of the absolute value of difference between the empirical and theoretical density functions. 相似文献
8.
U — [0, 1] Y — . X=[1–U
1/v
/Y], U Y. 相似文献
9.
E. Csáki 《Probability Theory and Related Fields》1980,54(3):287-301
Summary Let W(t) be a standard Wiener process and let f(x) be a function from the compact class in Strassen's law of the iterated logarithm. We investigate the lim inf behavior of the variable sup ¦W(xT)(2T loglog T)–1/2–f(x)¦, 0x1 suitably normalized as T.This extends Chung's result valid for f(x)0, stating that lim inf.[ sup ¦(2T loglogT)–1/2
W(xT)¦(loglog T)–1]=/4 a.s. T 0x1 相似文献
10.
R. A. Danao 《Journal of Optimization Theory and Applications》1997,95(2):445-454
Consider the parametric linear complementarity problem w=Mz+q+p, w0, z0, w
T
z=0, where p0, 0q0, and 0. We show that a necessary condition for every complementary map z() to be isotone for every nonzero q0 and every p is that M be either a P-matrix or a
-matrix. The Cottle necessary and sufficient conditions for strong and uniform isotonicity for P-matrices are restated, with slight modifications, for
-matrices. 相似文献
11.
Huang Zhiyuan 《Probability Theory and Related Fields》1984,66(1):25-40
Summary A general theory of stochastic integral in the abstract topological measurable space is established. The martingale measure is defined as a random set function having some martingale property. All square integrable martingale measures constitute a Hilbert space M
2. For each M
2, a real valued measure on the predictable -algebra is constructed. The stochastic integral of a random function
with respect to is defined and investigated by means of Riesz's theorem and the theory of projections. The stochastic integral operator I
is an isometry from L
2() to a stable subspace of M
2, its inverse is defined as a random Radon-Nikodym derivative. Some basic formulas in stochastic calculus are obtained. The results are extended to the cases of local martingale and semimartingale measures as well. 相似文献
12.
The non-commutative torus C
*(n,) is realized as the C*-algebra of sections of a locally trivial C*-algebra bundle over S with fibres isomorphic to C
*n/S, 1) for a totally skew multiplier 1 on n/S. D. Poguntke [9] proved that A
is stably isomorphic to C(S) C(*( Zn/S, 1) C(S) A Mkl( C) for a simple non-commutative torus A and an integer kl. It is well-known that a stable isomorphism of two separable C*-algebras is equivalent to the existence of equivalence bimodule between them. We construct an A-C(S) A-equivalence bimodule. 相似文献
13.
Rolf Schneider 《Discrete and Computational Geometry》1987,2(1):223-232
Let be a locally finite system of hyperplanes in
d
with the property that the cells of the induced cell complex decomposition of
d
have uniformly bounded diameters. If is simple and the density of the vertices in exists, then the density of thek-cells in exists and can be given explicitly (k = 1, ...,d). Also, the mean number ofj-faces of thek-cells in exists and can be calculated. For certain nonsimple systems , corresponding inequalities are obtained. 相似文献
14.
Klaus-Jürgen Eckardt 《manuscripta mathematica》1976,18(1):43-55
The problem of existence of wave operators for the Klein-Gordon equation (
t
2
–+2+iV1t+V2)u(x,t)=0 (x R
n,t R, n3, >0) is studied where V1 and V2 are symmetric operators in L2(R
n) and it is shown that conditions similar to those of Veseli-Weidmann (Journal Functional Analysis 17, 61–77 (1974)) for a different class of operators are also sufficient for the Klein-Gordon equation. 相似文献
15.
Summary Fix a curve X of genus g and L Pic
d
(X). Let L(X) be the image of X through the complete linear system H0(X, L). Here we prove that a general projection of L(X) intoP
N
has maximal rank if either (a) N4, 0gN–1, dg+N, or (b) dd (g, N) for suitable d(g, N). 相似文献
16.
La notion de -valeur propre de –+V sera définie pour un ouvert borné de R
d
; étant une mesure dans la classe de Kato généralisée. On établira une estimation du nombre des -valeurs propres inférieures à un réel positif E.The notion of -eigenvalue of –+V will be defined for a bounded open subset of R
d
; is in the generalized Kato class. An estimate for the number of -eigenvalues which are smaller then a positive real E is given. 相似文献
17.
Asao Arai 《Integral Equations and Operator Theory》1995,21(2):139-173
LetA andB be two anticommuting self-adjoint operators andV() be a symmetric operator in a Hilbert space, where >0 is a parameter. It is proven that, under some conditions forV(), the resolvents of A+2
B±2|B|+V() converge as . Applications to the nonrelativistic-limit problem of Dirac operators and supersymmetry are discussed.This work is supported by the Grant-In-Aid 0560139 for science research from the Ministry of Education, Japan. 相似文献
18.
Summary We study integral functionals of the formF(u, )=
f(u)dx, defined foru C1(;R
k), R
n
. The functionf is assumed to be polyconvex and to satisfy the inequalityf(A) c0¦(A)¦ for a suitable constant c0 > 0, where (A) is then-vector whose components are the determinants of all minors of thek×n matrixA. We prove thatF is lower semicontinuous onC
1(;R
k) with respect to the strong topology ofL
1(;R
k). Then we consider the relaxed functional , defined as the greatest lower semicontinuous functional onL
1(;R
k
) which is less than or equal toF on C1(;R
k). For everyu BV(;R
k) we prove that (u,)
f(u)dx+c0¦Dsu¦(), whereDu=u dx+Dsu is the Lebesgue decomposition of the Radon measureDu. Moreover, under suitable growth conditions onf, we show that (u,)=
f(u)dx for everyu W1,p(;R
k), withp min{n,k}. We prove also that the functional (u, ) can not be represented by an inte- gral for an arbitrary functionu BVloc(R
n;R
k). In fact, two examples show that, in general, the set function (u, ) is not subadditive whenu BVloc(R
n;R
k), even ifu W
loc
1,p
(R
n;R
k) for everyp < min{n,k}. Finally, we examine in detail the properties of the functionsu BV(;R
k) such that (u, )=
f(u)dx, particularly in the model casef(A)=¦(A)¦. 相似文献
19.
Xiaodong Zhou 《Applied Mathematics and Optimization》1992,25(3):263-285
We study the parabolic problemu/t=divx p() in the function space L2(0, T; BV()). Here is the linear growth functional arising from the study of plastic antiplanar shear deformations. 相似文献
20.
Liming Yang 《Integral Equations and Operator Theory》1996,25(3):373-376
Let 1<p< and
. LetC
q
denote the Bessel capacity in the plane. Let
be the set of homomorphisms ofH
(G) such that (z)= and letNP denote the set of points in G for which
is not a peak set forH
(G). In this note, we show that ifC
q
(NP)=0, thenH
(G) is dense inL
a
p
(G), the Bergman space overG.Partially supported by NSF DMS-9401234 相似文献