共查询到20条相似文献,搜索用时 218 毫秒
1.
Paul Jolissaint 《K-Theory》1989,2(6):723-735
We associate to any length function L on a group a space of rapidly decreasing functions on (in the l
2 sense), denoted by H
L
(). When H
L
() is contained in the reduced C*-algebra C
r
*
() of (), then it is a dense *-subalgebra of C
r
*
() and we prove a theorem of A. Connes which asserts that under this hypothesis H
L
() has the same K-theory as C
r
*
(). We introduce another space of rapidly decreasing functions on (in the l
1 sense), denoted by H
L
1,
(), which is always a dense *-subalgebra of the Banach algebra l
1(), and we show that H
L
1,
() has the same K-theory as l
1(). 相似文献
2.
3.
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
4.
John S. Caughman IV 《Journal of Algebraic Combinatorics》2002,15(3):223-229
Let denote a bipartite distance-regular graph with diameter D 3 and valency k 3. Suppose 0, 1, ...,
D
is a Q-polynomial ordering of the eigenvalues of . This sequence is known to satisfy the recurrence
i – 1 –
i
+
i + 1 = 0 (0 > i > D), for some real scalar . Let q denote a complex scalar such that q + q
–1 = . Bannai and Ito have conjectured that q is real if the diameter D is sufficiently large.We settle this conjecture in the bipartite case by showing that q is real if the diameter D 4. Moreover, if D = 3, then q is not real if and only if 1 is the second largest eigenvalue and the pair (, k) is one of the following: (1, 3), (1, 4), (1, 5), (1, 6), (2, 4), or (2, 5). We observe that each of these pairs has a unique realization by a known bipartite distance-regular graph of diameter 3. 相似文献
5.
Let {W(s)}
s
0 be a standard Wiener process. The supremum of the squared Euclidian norm Y (t)2, of the R2-valued process Y(t)=(1/t
W(t), {12/t
3 int0
t
s dW (s)– {3/t} W(t)), t [, 1], is the asymptotic, large sample distribution, of a test statistic for a change point detection problem, of appearance of linear trend. We determine the asymptotic behavior P {sup
t
[, 1] Y(t)2 > u as u , of this statistic, for a fixed (0,1), and for a moving = (u) 0 at a suitable rate as u . The statistical interest of our results lie in their use as approximate test levels. 相似文献
6.
Thomas Deck 《Annals of Global Analysis and Geometry》1994,12(1):305-312
We investigate two-dimensional timelike surfaces in a Lorentz manifold (X,g). It is shown that orientable surfaces with two spacelike boundary components (homeomorphic toS
1) are necessarily of topological type [0,1] x S1. We treat the initial value problem of a string (known from physics) as a purely geometric problem: Find a minimal surface which is specified by an initial curve and by a distribution of timelike tangent planes along . We prove the local existence and uniqueness of and also obtain global existence for special types (X,g). Global existence does not generally hold; we give a counter-example, which can be interpreted as a string collapsing into a black hole. 相似文献
7.
8.
In this paper, we construct, by effective induction, a 11 equivalence relation E on for which there is no largest E-thin E-invariant 11 subset of by effective induction. This result answers a problem asked by Kechris in [1]Mathematics Subject Classification: 03E15Revised version: 13 January 2000 相似文献
9.
We prove L
r
estimates for the Dirichlet problem –div(a(x,u,Du))=f with f in L
q
for 1q+, where the operator satisfies (|s|)||
p
a(x,s,), with p>1. These estimates are obtained without symmetrization and are sharp in some cases. 相似文献
10.
In this paper, we have proven that for the Jordan blockS() withS() (SI),
i=1
n
S() =S()
(n)
(n 1) has unique finite (SI) decomposition up to a similarity. As result, we obtain that ifV is a Volterra operator onH=L
2([0, 1]), thenV
(n)
has unique finite (SI) decomposition.This project was supported by National Natural Science Foundation of China. 相似文献
11.
We use the eta invariant to study the connective K-theory groups ko
m
(B
) of the classifying space for the cyclic group where - 2 2. 相似文献
12.
Horst Elmar Winkelnkemper 《Annals of Global Analysis and Geometry》1992,10(3):209-218
Let
t
be the flow (parametrized with respect to arc length) of a smooth unit vector field v on a closed Riemannian manifold M
n
, whose orbits are geodesics. Then the (n-1)-plane field normal to v, v, is invariant under d
t
and, for each x M, we define a smooth real function
x
(t) : (1 +
i
(t)), where the i(t) are the eigenvalues of AA
T, A being the matrix (with respect to orthonormal bases) of the non-singular linear map d2t
, restricted to v at the point x
-t M
n.Among other things, we prove the
Theorem (Theorem II, below). Assume v is also volume preserving and that
x
'
(t) 0 for all x M and real t; then, if
x
t
: M M is weakly missng for some t, it is necessary that vx 0 at all x M. 相似文献
13.
14.
We consider the q-hypergeometric equation with q
N = 1 and , , . We solve this equation on the space of functions given by a power series multiplied by a power of the logarithmic function. We prove that the subspace of solutions is two-dimensional over the field of quasi-constants. We get a basis for this space explicitly. In terms of this basis, we represent the q-hypergeometric function of the Barnes type constructed by Nishizawa and Ueno. Then we see that this function has logarithmic singularity at the origin. This is a difference between the q-hypergeometric functions with 0 < |q| < 1 and at |q| = 1. 相似文献
15.
In the literature (see [5, 6, 8]) there are two families of spaces called Kondratiev spaces: (c)± and (S
c)± for 0 1. We investigate the relation between the spaces and show that they are topologically isomorphic when (d) L2 (d) (d) is the underlying Gel'fand triple for (c)±. In this case we also give the explicit relation between the S-transform and -transform on (c)-1 and (S
c)-1, respectively. 相似文献
16.
In this paper we continue the study of the subgradient method for nonsmooth convex constrained minimization problems in a uniformly convex and uniformly smooth Banach space. We consider the case when the stepsizes satisfy
k=1
k
=, lim
k
k
=0. 相似文献
17.
Given a nuclear b-space N, we show that if is a finite or -finite measure space and 1p, then the functors L
loc
p
(,N.) and NL
p
(,.) are isomorphic on the category of b-spaces of L. Waelbroeck. 相似文献
18.
A. B. Aleksandrov 《Journal of Mathematical Sciences》1993,63(2):115-129
Let be an inner function, let C, ¦¦=1. Then the harmonic function [(+)]/(–)] is the Poisson integral of a singular measure
D. N. Clark's known theorem enables us to identify in a natural manner the space H2 H2 with the space L2
(
).Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova Akademii Nauk SSSR, Vol. 170, pp. 7–33, 1989. 相似文献
19.
Ranja Roy 《K-Theory》1999,17(3):209-213
In the paper Geometric K-Theory for Lie Groups and Foliations, Baum and Connes conjecture in a remark following Corollary 2 of their famous Isomorphism conjecture that for a finitely generated group with torsion, the trace map tr: K0(C*)R maps K0(C*) onto the additive subgroup of Q generated by all rational numbers of the form 1/n where n is the order of a finite subgroup of . We construct a counterexample to this conjecture. 相似文献
20.
On-line k-Truck Problem and Its Competitive Algorithms 总被引:1,自引:0,他引:1
In this paper, based on the Position Maintaining Strategy (PMS for short), on-line scheduling of k-truck problem, which is a generalization of the famous k-server problem, is originally presented by our team. We proposed several competitive algorithms applicable under different conditions for solving the on-line k-truck problem. First, a competitive algorithm with competitive ratio 2k+1/ is given for any 1. Following that, if (c+1)/(c-1) holds, then there must exist a (2k-1)-competitive algorithm for k-truck problem, where c is the competitive ratio of the on-line algorithm about the relevant k-server problem. And then a greedy algorithm with competitive ratio 1+/, where lambda is a parameter related to the structure property of a given graph, is given. Finally, competitive algorithms with ratios 1+1/ are given for two special families of graphs. 相似文献