共查询到20条相似文献,搜索用时 477 毫秒
1.
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
2.
Gikō Ikegami 《Inventiones Mathematicae》1989,95(2):215-246
Summary We define a constraint system
, [0,0), which is a kind of family of vector fields
on a manifold. This is a generalized version of the family of the equations
, [0,0),x
m
,y
n
. Finally, we prove a singular perturbation theorem for the system
, [0,0).Dedicated to Professor Kenichi Shiraiwa on his 60th birthday 相似文献
3.
F. Schipp 《Analysis Mathematica》1990,16(2):135-141
H={h
1,I } — , . : , I ¦(I)¦=¦I¦, ¦I¦ — I. H H
={h
(I),I} . , , . L
p
.
Dedicated to Professor B. Szökefalvi-Nagy on his 75th birthday
This research was supported in part by MTA-NSF Grants INT-8400708 and 8620153. 相似文献
Dedicated to Professor B. Szökefalvi-Nagy on his 75th birthday
This research was supported in part by MTA-NSF Grants INT-8400708 and 8620153. 相似文献
4.
M. Kh. Khafizov 《Mathematical Notes》1978,23(6):469-473
Let be a ring of sets, X a normed space, : X ( ) a bounded family of triangular functions. The following generalized Nikodym theorem is established: the family {} is uniformly bounded on if and only if it is bounded on every sequence of pairwise disjoint sets of which the union is a part of some set in . An analogous criterion is established also for semiadditive functions. In addition, it is shown that uniform boundedness of a family of triangular functions is preserved in passing from a ring to the -ring it generates.Translated from Matematicheskie Zametki, Vol. 23, No. 6, pp. 855–861, June, 1978. 相似文献
5.
R. Ž. Nurpeisov 《Analysis Mathematica》1989,15(2):127-143
H
(G), f(g)H
(G) , (, 1)- OHMC G. , OHMC, A. H. . , . , OHMC, lim supp
n=, , ,n .. . , 117 234 . . - 相似文献
6.
O. V. Kuznetsov 《Journal of Mathematical Sciences》1994,72(4):3182-3188
Suppose that in a domain R(, B) of variables (r, ): (0 r , 1 +B(r–r
0
) 2–B(r–r0), where > 0, B > 0, 1 < 0 < 2 are numbers) a metric ds2 = dr2 +G(r, )d
2 and a function k(r, ) are given. The problem of isometrically immersing ds2
in E
4
with prescribed Gaussian torsion is considered. The following is proved: The class C
5
metric ds
2
is locally realized in the form of a class C
3
surface F
2
whose Gaussian torsion is the prescribed class C
3
function (r, ).Translated from Ukrainskii Geometricheskii Sbornik, No. 35, pp. 38–47, 1992. 相似文献
7.
Moshe Sniedovich 《Mathematical Programming》1989,43(1-3):329-347
We propose a solution strategy for fractional programming problems of the form max
xx
g(x)/ (u(x)), where the function satisfies certain convexity conditions. It is shown that subject to these conditions optimal solutions to this problem can be obtained from the solution of the problem max
xx
g(x) + u(x), where is an exogenous parameter. The proposed strategy combines fractional programming andc-programming techniques. A maximal mean-standard deviation ratio problem is solved to illustrate the strategy in action. 相似文献
8.
M. S. Sgibnev 《Mathematical Notes》1977,22(5):916-920
Let {n} be a sequence of identically distributed independent random variables,M1=<0,M
1
2
<;S
0=0,S
n
=1+2,+...+
n, n1;¯ S=sup {S
n
n=0.} The asymptotic behavior ofP(¯ St) as t is studied. If
t
P
(1x dx=0((t)), thenP(¯ St)– 1/¦¦
t
P (1x dx=0((t)) (t) is a positive function, having regular behavior at infinity.Translated from Matematicheskie Zametki, Vol. 22, No. 5, pp. 763–770, November, 1977.The author thanks B. A. Rogozin for the formulation of the problem and valuable remarks. 相似文献
9.
N. M. Ivochkina 《Journal of Mathematical Sciences》1984,26(6):2349-2359
One proves that a priori boundedness of the norm
of the solution of the problem det(Uxx)=f(x,u,ux)>>0,u¦=0. The magnitudes of the exponents,() depends on whether the arguments u p occur or not in f (x,u,p).Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 125, pp. 74–90, 1983. 相似文献
10.
Summary We consider a (possibly) vector-valued function u: RN, Rn, minimizing the integral
, 2-2/(n*1)<p<2, whereD
i
u=u/x
i
or some more general functional retaining the same behaviour, we prove higher integrability for Du: D1 u,..., Dn–1 u Lp/(p-1) and Dnu L2; this result allows us to get existence of second weak derivatives: D(D1 u),...,D(Dn–1u)L2 and D(Dn u) L
p.This work has been supported by MURST and GNAFA-CNR. 相似文献
11.
James Renegar 《Mathematical Programming》1988,40(1-3):113-163
We examine the efficiency of PL path following algorithms in followingF
T
-1
(0), whereF
T is the PL approximation, induced by the simplicial triangulationT, to a mapf:
n
n-1. In particular, we consider the problem of determining an upper bound on the expected number of pivots made per unit length off
–1(0) that is approximated. We show that if the sizes of the simplices ofT are sufficiently small, where sufficiently small is an explicitly given quantity dependent on measurements of how nicef is, then the average directional density ofT, as introduced by Todd, really does give a good approximation to the expected number of pivots made, confirming what researchers have believed on intuitive grounds for a decade. Because what constitutes sufficiently small is a precisely given quantity, i.e., non-asymptotic, we are able to provide some rigorous justification for the claim that the expected number of pivots grows only polynomially inn, the number of variables.Several other issues are also examined.Research supported by an NSF Mathematical Sciences Postdoctoral Research Fellowship. This research was performed while the author was a member of the Mathematical Sciences Research Institute, Berkeley, California. 相似文献
12.
B. T. Rumov 《Mathematical Notes》1976,19(4):376-382
This paper proves the existence of resolvable block designs with divisibility into groups GD(v; k, m; 1, 2) without repeated blocks and with arbitrary parameters such that 1 = k, (v–1)/(k–1) 2 vk–2 (and also 1 k/2, (v–1)/(2(k–1)) 2 vk–2 in case k is even) k 4 andp=1 (mod k–1), k < p for each prime divisor p of number v. As a corollary, the existence of a resolvable BIB-design (v, k, ) without repeated blocks is deduced with X = k (and also with = k/2 in case of even k) k
, where a is a natural number if k is a prime power and=1 if k is a composite number.Translated from Matematicheskie Zametki, Vol. 19, No. 4, pp. 623–634, April, 1976. 相似文献
13.
We study the limiting behavior of the weighted central paths{(x(), s())}
> 0 in linear programming at both = 0 and = . We establish the existence of a partition (B
,N
) of the index set { 1, ,n } such thatx
i() ands
j
() as fori B
, andj N
, andx
N (),s
B () converge to weighted analytic centers of certain polytopes. For allk 1, we show that thekth order derivativesx
(k)
() ands
(k)
() converge when 0 and . Consequently, the derivatives of each order are bounded in the interval (0, ). We calculate the limiting derivatives explicitly, and establish the surprising result that all higher order derivatives (k 2) converge to zero when . 相似文献
14.
We construct an asymptotic formula for a sum function for
a
(), where
a
() is the sum of the ath powers of the norms of divisors of the Gaussian integer on an arithmetic progression 0 (mod ) and in a narrow sector 1 arg < 2. For this purpose, we use a representation of
a
(n) in the form of a series in the Ramanujan sums. 相似文献
15.
Karl Dilcher 《Aequationes Mathematicae》1994,48(1):55-85
Summary We study a class of generalized gamma functions
k
(z) which relate to the generalized Euler constants
k
(basically the Laurent coefficients of(s)) as (z) does to the Euler constant. A new series expansion for
k
is derived, and the constant term in the asymptotic expansion for log
k
(z) is studied in detail. These and related constants are numerically computed for 1 k 15. 相似文献
16.
17.
Let X,X
n
;n1 be a sequence of real-valued i.i.d. random variables with E(X)=0. Assume B(u) is positive, strictly increasing and regularly-varying at infinity with index 1/2<1. Set b
n
=B(n),n1. If
and
for some [0,), then it is shown that
and
for every real triangular array (a
n,k
;1kn,n1) and every array of bounded real-valued i.i.d. random variables W,W
n,k
;1kn,n1`` independent of {X,X
n
;n1}, where (W)=(E(W–E(W))2)1/2. An analogous law of the iterated logarithm for the unweighted sums
n
k=1
X
k
;n1} is also given, along with some illustrative examples. 相似文献
18.
Mario Petrich 《Monatshefte für Mathematik》1993,116(3-4):287-298
For a Rees matrix semigroupS with normalized sandwich matrix and C(S), the congruence lattice ofS, we consider the lattice generated by {itpTl, pK, pTr, ptl, pk, ptr}. HerepT
1 andpt
l
are the upper and lower ends of the interval which makes up the
i
-class of ,
i
being the left trace relation onC(S). The remaining symbols have the analogous meaning relative to the kernel and the right trace relations. We also consider the lattice generated by {T
l, K, Tr, tl, k, tr} where and are the equality and the universal relations onS, respectively. In both cases, we find lattices freest relative to these lattices and represent them as distributive lattices with generators and relations.With 3 Figures 相似文献
19.
The number of subgroups of type and cotype in a finite abelian p-group of type is a polynomialg
with integral coefficients. We prove g
has nonnegative coefficients for all partitions and if and only if no two parts of differ by more than one. Necessity follows from a few simple facts about Hall-Littlewood symmetric functions; sufficiency relies on properties of certain order-preserving surjections that associate to each subgroup a vector dominated componentwise by . The nonzero components of (H) are the parts of , the type of H; if no two parts of differ by more than one, the nonzero components of – (H) are the parts of , the cotype of H. In fact, we provide an order-theoretic characterization of those isomorphism types of finite abelian p-groups all of whose Hall polynomials have nonnegative coefficients. 相似文献
20.
Richard Koch 《Journal of Geometry》1998,62(1-2):176-189
In Euclidean space E3, let be a (regular C-) minimal surface without planar points having locally (without loss of generality) the spherical representation n(u,v)=(cos v/cosh u, sin v/cosh u, tanh u), (u,v)G2. The corresponding (isothermal) parametrization : x(u,v), (u,v)G can be expressed using agenerating Function (u,v) which satisfies uu +
vv – 2utanh u + =0; the v-curves (coordinate curves u=u0) in , along each of which the angle between the normal n(u,v) of and the x3-axis is constant, are thevertical- isophotes of , the u-curves (v=v0) being their orthogonal trajectories (theorems 1, 2). Considering u-curves and/or v-curves of having additional geometric properties (curves of constant/steepest slope, curves of constant Gaussian curvature, asymptotic curves, lines of curvature or geodesies of ) we prove many newgeometric characterizations of theright helicoid, thecatenoid andScherk's second surface (theorems 3–7). All of these surfaces areminimal hélicoidal surfaces. 相似文献