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1.
We express the real connective K-theory groups
o4k–1(B
Q
) ofthe quaternion group Q
of order = 2
j
8 in terms of therepresentation theory of Q
by showing
o4k–1(B
Q
) =
Sp(S
4k+3/Q
)where is any fixed point free representation of Q
in U(2k + 2). 相似文献
2.
Jorge Almeida 《Algebra Universalis》1989,26(1):16-32
For an ordinal and a class
of topological algebras of a given type (which may be infinite and may contain inflnitary operations), an-aryimplicit operation on
is any new-ary operation whose introduction does not eliminate any continuous homomorphisms between members of
. The set of all-ary implicit operations on
is denoted by
and forms an algebra of the given type which is endowed with the least topology making continuous all homomorphisms into members of
. With this topology,
is a topological algebra in which the subalgebra
of all-ary operations on
which are induced by terms is dense, provided that
is closed under the formation of closed subalgebras and finitary direct products. This is obtained by realizing
as an inverse limit of-generated members of
. These results are applied to pseudovarieties of topological and finite algebras.This work was supported, in part, by INIC grant 85/CEX/4. This paper was written while the author was a faculty member at the Universidade do Minho.Presented by Ralph McKenzie. 相似文献
3.
Alain Rivière 《Geometriae Dedicata》2001,85(1-3):217-235
For a separable Hilbert space E whose dimension is 2 and for an open subset of E, not empty and different from E, let
be the set of all points of which have at least two projections on the close set E\, and let
be the set of all the centres of the open balls contained in and which are maximal for inclusion. We show that the Hausdorff dimension dimH(
) of
may be any real value s such that 0sdim E; we also show that can be chosen so that
is everywhere dense in and so that we have dimH(
)=1.Associons à un ouvert d'un espace de Hilbert séparable E de dimension 2, non vide et distinct de E, l'ensemble
des points de admettant plusieurs projections sur le fermé E\, et l'ensemble
des centres des boules ouvertes inclues dans et maximales pour l'inclusion. Nous montrons d'une part que la dimension de Hausdorff dimH(
) de
peut prendre toute valeur réelle s telle que 0sdim E, et d'autre part qu'on peut choisir de sorte que
soit dense dans et qu'on ait dimH(
)=1. 相似文献
4.
A. G. Areshkina 《Mathematical Notes》1998,64(2):154-158
On a measurable space (T, , ) we choose an additive measure: Z (Z is a Banach space) with the following property: for alle , we have
; this measure defines an indefinite integral over the measure onL
2
(T, ,). We prove that if {
n
(t)}
n
=1/
is an orthonormal basis inL
2 and
n
(e)=e
n
(t) d, then any additive measure: Z whose Radon-Nikodým derivatived/d belongs toL
2 is uniquely expandable in a series(e)=
n
=1/
n
n(e) that converges to(e) uniformly with respect toe can be differentiated term-by-term, and satisfies
n
=1/
n
/2
<. In the caseL
2[0,2],Z=, the Fourier series of a 2-periodic absolutely continuous functionF(t) such thatF'(t) L
2[0, 2] is superuniformly convergent toF(t).Translated fromMatematicheskie Zametki, Vol. 64, No. 2, pp. 180–184, August, 1998. 相似文献
5.
H. L. Stalford 《Journal of Optimization Theory and Applications》1995,86(2):327-346
A new property called scalar-quadratic is presented for establishing the stabilizability of linear time-varyring uncertain systems. It is applied to a well-known linear time-varying system OL which contains two uncertainties 1(t) and 2(t). Using the Lyapunov functionsV(x)=x
T
Px, whereP is a constant postitive-definite symmetric matrix, previous authors have shown that OL is stabilizable by linear static controllers when the time-varying uncertainties are bounded by a normalized bound
satisfying
< 0.8. We extend the bound to
< 1.0 by using the more general Lyapunov functions satisfying the scalar-quadratic propertyV(ax)=a
2
V(x), aR, xR
0
2
.Our proof uses a hexagon as a closed, convex hypersuface to construct a scalar-quadratic Lyapunov function, so that the Lyapunov time derivative satisfies the quadratic convergence condition
, >0, for the closed-loop system CL formed from OL and a stabilizing linear static controller. The critical condition in the proof of the quaratic convergence ondition is the satisfaction of the inequality
, where max is a normalization bound for 1(t) and 2(t) and wheree
1 ande
2 are parameters for the controller. For the controller parametrized bye
1=8 ande
2=20, this inequality reduces to max < 2.2096. This result, in particular, establishes that the Petersen counterexample is stabilitzable by the linear static controller withe
1=8 ande
2=20. Furthermore, it establishes the amazing result that OL is stabilizable by a linear static controlle on any compact subset of the constant uncertainaty controllability space defined by 1>0 and 2>0. 相似文献
6.
Zusammenfassung Es wird die Fortpflanzung elastisch-plastischer Spannungswellen in einem unendlichen Medium betrachtet, welches einer idealen Spannungs-Verformungs-Kurve folgt, Trescas Fliesskriterium unterworfen ist und einen sphärischen Hohlraum enthält, wobei an der Fläche des Hohlraumes ein Stoss
angenommen wird. Ein rechnerisches Verfahren, basiert auf endliche Differenzen, wird entwickelt and ein Beispiel gegeben.
Notation radial stress - tangential stress - K yield stress - rr non-dimensional radial stress ( /K) - non-dimensional tangential stress ( /K) - , Lame's constants - K b Bulk constant (=(3+2)/3) - v Poisson's constant - Material density - C Elastic wave velocity (=((+2)/)1/2) - C p Plastic wave velocity (=(K b /)1/2) - distance from center of cavity - r 0 cavity radius - v non-dimensional radial co-ordinate (= /r 0) - time - t non-dimensional time (=C /r 0) - radial displacement - u non-dimensional radial displacement (=/r 0) - particle velocity - v non-dimensional particle velocity (= /C) - pressure - P(t) non-dimensional pressure (= /K) 相似文献
Notation radial stress - tangential stress - K yield stress - rr non-dimensional radial stress ( /K) - non-dimensional tangential stress ( /K) - , Lame's constants - K b Bulk constant (=(3+2)/3) - v Poisson's constant - Material density - C Elastic wave velocity (=((+2)/)1/2) - C p Plastic wave velocity (=(K b /)1/2) - distance from center of cavity - r 0 cavity radius - v non-dimensional radial co-ordinate (= /r 0) - time - t non-dimensional time (=C /r 0) - radial displacement - u non-dimensional radial displacement (=/r 0) - particle velocity - v non-dimensional particle velocity (= /C) - pressure - P(t) non-dimensional pressure (= /K) 相似文献
7.
Let |E(G)|= andf, a 1-1 mapping ofV(G) into {0,1,...,}. Thenf is called a -valuation ofG if the induced function given by
, for alluvE(G) is 1-1. A -valuationf is called an -valuation ofG if there exists a nonnegative number such that for everyuvE(G) withf(u)<f(v),f(u)<f(v). Let
denote the graph of then-dimensionalG-cube. ForG=K
3, 3,K
4, 4, andP
k
,it is shown that for any positive integern, then-dimensionalG-cube has an -valuation. This gives rise to decompositions of some complete graphs into certain bipartite graphs. 相似文献
8.
Let X and Y be two Hilbert spaces, and
the space of bounded linear transformations from X into Y. Let {A
}
be a weakly periodic sequence of period T. Spectral theory of weakly periodic sequences in a Hilbert space is studied by H. L. Hurd and V. Mandrekar (1991). In this work we proceed further to characterize {A
n} by a positive measure and a number T of
-valued functions a
0, . . . ,a
T–1; in the spectral form
, where
and is an
-valued Borel set function on [0, 2) such that
相似文献
9.
D. V. Millionshchikov 《Mathematical Notes》2005,77(1-2):61-71
The cohomology H* (G/,) of the de Rham complex *(G/) of a compact solvmanifold G/ with deformed differential d = d + , where is a closed 1 -form, is studied. Such cohomologies naturally arise in Morse-Novikov theory. It is shown that, for any completely solvable Lie group G containing a cocompact lattice G, the cohomology H*(G/, ) is isomorphic to the cohomology H*(
) of the tangent Lie algebra
of the group G with coefficients in the one-dimensional representation :
defined by () = (). Moreover, the cohomology H
*(G/,) is nontrivial if and only if -[] belongs to a finite subset
of H
1(G/,) defined in terms of the Lie algebra
.Translated from Matematicheskie Zametki, vol. 77, no. 1, 2005, pp. 67–79.Original Russian Text Copyright © 2005 by D. V. Millionshchikov.This revised version was published online in April 2005 with a corrected issue number. 相似文献
10.
Richard Sowers 《Probability Theory and Related Fields》1992,92(3):393-421
Summary In this paper we establish a large deviations principle for the invariant measure of the non-Gaussian stochastic partial differential equation (SPDE)
t
v
=v
+f(x,v
)+(x,v
)
. Here is a strongly-elliptic second-order operator with constant coefficients, h:=DH
xx-h, and the space variablex takes values on the unit circleS
1. The functionsf and are of sufficient regularity to ensure existence and uniqueness of a solution of the stochastic PDE, and in particular we require that 0<mM wherem andM are some finite positive constants. The perturbationW is a Brownian sheet. It is well-known that under some simple assumptions, the solutionv
2 is aC
k
(S
1)-valued Markov process for each 0<1/2, whereC
(S
1) is the Banach space of real-valued continuous functions onS
1 which are Hölder-continuous of exponent . We prove, under some further natural assumptions onf and which imply that the zero element ofC
(S
1) is a globally exponentially stable critical point of the unperturbed equation
t
0 = 0 +f(x,0), that has a unique stationary distributionv
K,
on (C
(S
1), (C
K
(S
1))) when the perturbation parameter is small enough. Some further calculations show that as tends to zero,v
K,
tends tov
K,0, the point mass centered on the zero element ofC
(S
1). The main goal of this paper is to show that in factv
K,
is governed by a large deviations principle (LDP). Our starting point in establishing the LDP forv
K,
is the LDP for the process , which has been shown in an earlier paper. Our methods of deriving the LDP forv
K,
based on the LDP for are slightly non-standard compared to the corresponding proofs for finite-dimensional stochastic differential equations, since the state spaceC
(S
1) is inherently infinite-dimensional.This work was performed while the author was with the Department of Mathematics, University of Maryland, College Park, MD 20742, USA 相似文献
11.
Cindy de Volder 《Geometriae Dedicata》2001,85(1-3):237-251
We consider the blowing-up Y
k
of the projective plane along k general points P
1,...,P
k
. Let
k
: Y
k
2 be the projection map and E
i
the exceptional divisor corresponding to P
i
for 1ik. For m2 and km(m+3)/2–4 let
k
be the invertible sheaf
k
*(
2(m))
Y
k
(–E
1–···–E
k
) on Y
k
, and let k: Y
k
N
be the morphism corresponding to
k
. As
k
is a local embedding, the Gauss map
k
corresponding to
k
is defined on Y
k
by
k
(x)=(d
x
k
)(T
x
(Y
k
)) for all xY
k
. We prove that this Gauss map
k
is injective. 相似文献
12.
Donald I. Cartwright Anna Maria Mantero Tim Steger Anna Zappa 《Geometriae Dedicata》1993,47(2):167-223
If (P, L) is a projective plane and is a triangle presentation compatible with a point-line correspondence :P L, then gives rise to a group and a thick building of typeÃ
2 on the vertices of which acts simply transitively. We find all triangle presentations (up to natural equivalence) compatible with some point-line correspondence :P L, when (P, L) is the projective plane of orderq=2 orq=3. For some, but not all, of these , is isomorphic to the building associated withG=PGL(3,K) whereK is a local field with discrete valuation and residual field of orderq. We identify the for which this is the case, and in these cases, find embeddings of intoG. We also describe the arithmetic nature of these groups. 相似文献
13.
Mark S. MacLean 《Journal of Algebraic Combinatorics》2003,17(2):125-147
Let denote a bipartite distance-regular graph with diameter D 4, valency k 3, and distinct eigenvalues 0 > 1 > ··· > D. Let M denote the Bose-Mesner algebra of . For 0 i D, let E
i denote the primitive idempotent of M associated with
i
. We refer to E
0 and E
D as the trivial idempotents of M. Let E, F denote primitive idempotents of M. We say the pair E, F is taut whenever (i) E, F are nontrivial, and (ii) the entry-wise product E F is a linear combination of two distinct primitive idempotents of M. We show the pair E, F is taut if and only if there exist real scalars , such that
i + 1
i + 1 –
i – 1
i – 1 =
i
(
i + 1 –
i – 1) +
i
(
i + 1 –
i – 1) + (1 i D – 1)where 0, 1, ...,
D
and 0, 1, ...,
D
denote the cosine sequences of E, F, respectively. We define to be taut whenever has at least one taut pair of primitive idempotents but is not 2-homogeneous in the sense of Nomura and Curtin. Assume is taut and D is odd, and assume the pair E, F is taut. We show
for 1 i D – 1, where = 1, = 1. Using these equations, we recursively obtain 0, 1, ..., D and 0, 1, ...,
D
in terms of the four real scalars , , , . From this we obtain all intersection numbers of in terms of , , , . We showed in an earlier paper that the pair E
1, E
d is taut, where d = (D – 1)/2. Applying our results to this pair, we obtain the intersection numbers of in terms of k, , 1, d, where denotes the intersection number c
2. We show that if is taut and D is odd, then is an antipodal 2-cover. 相似文献
14.
Stuart A. Steinberg 《Czechoslovak Mathematical Journal》2001,51(2):387-394
In an -group M with an appropriate operator set it is shown that the -value set (M) can be embedded in the value set (M). This embedding is an isomorphism if and only if each convex -subgroup is an -subgroup. If (M) has a.c.c. and M is either representable or finitely valued, then the two value sets are identical. More generally, these results hold for two related operator sets 1 and 2 and the corresponding -value sets
and
. If R is a unital -ring, then each unital -module over R is an f-module and has
exactly when R is an f-ring in which 1 is a strong order unit. 相似文献
15.
Alexander Kreuzer 《Geometriae Dedicata》1996,61(3):279-283
Let (P,
) and (P,
) be linear spaces satisfying the exchange axiom with dim P=dim P . Then a bijection :PP which maps collinear points onto collinear points is an isomorphism. Also a surjection :PP which maps any three non-collinear points to non-collinear points is an isomorphism. This assertion is not true if dim P is not finite. 相似文献
16.
Let {B
t
,t[0,1]} be a fractional Brownian motion with Hurst parameter H > 1/2. Using the techniques of the Malliavin calculus we show that the trajectories of the indefinite divergence integral
t
0
u
s
B
s
belong to the Besov space
p,q
for all
, provided the integrand u belongs to the space
. Moreover, if u is bounded and belongs to
for some even integer p2 and for some large enough, then the trajectories of the indefinite divergence integral
t
0
u
s
B
s
belong to the Besov space
p,
H
. 相似文献
17.
V. I. Ovchinnikov 《Functional Analysis and Its Applications》2005,39(1):46-56
The paper deals with interpolation orbits for linear operators acting from a arbitrary couple {
(U
0),
(U
1)} of weighted L
p
spaces into an arbitrary couple {
(V
0),
(V
1)} of such spaces, where 1 p
0,p
1,q
0,q
1 . Here L
p
(U) is the space of measurable functions f on a measure space such that fU L
p
, equipped with the norm
. The paper describes the orbits of arbitrary elements a
(U
0) +
(U
1). It contains proofs of the results announced in C. R. Acad. Sci. Paris, Ser. I, 334, 881–884 (2002).__________Translated from Funktsionalnyi Analiz i Ego Prilozheniya, Vol. 39, No. 1, pp. 56–68, 2005Original Russian Text Copyright © by V. I. OvchinnikovTranslated by V. I. Ovchinnikov 相似文献
18.
In this article we prove the equivalence between the strong isoperimetric inequality #A #A, for any subset A of countable graph cG, and the inequality
for any function with finite variation on cG and null at infinity, with optimal constant. More generally, we prove the equivalence between the isoperimetric inequality # A cP
-1(1/# A) # A and the inequality ||
||cM |
|var, where cM is a Young function and cP its conjugate, and we also obtain an isoperimetric inequality in
as an application. 相似文献
19.
Jean-Paul Bézivin 《Aequationes Mathematicae》1992,44(1):84-99
Résumé Soitq un nombre algébrique de module 1, qui ne soit pas une racine de l'unité, etP
[X, Y
0,Y
1] un polynôme non nul. Dans cet article, nous montrons que toute solution de l'équation fonctionnelleP(z, (z), (qz))=0, qui est une série formelle (z) dansQ[[z]], a un rayon de convergence non nul.
Summary Letq Q be an algebraic number of modulus one that is not a root of unity. LetP Q[X, Y 0,Y 1] be a non zero polynomial. In this paper, we show that every formal power series,(z) Q[[z]], solution of the functional equationP(z), (z), (qz)) = 0 has a non zero radius of convergence.相似文献
20.
Summary Let (W, H, ) be an abstract Wiener space and letR(w) be a strongly measurable random variable with values in the set of isometries onH. Suppose that Rh is smooth in the Sobolev sense and that it is a quasi-nilpotent operator onH for everyhH. It is shown that (R(w)h) is again a Gaussian (0, |h|
H
2
)-random variable. Consequently, if (e
i
,i)W
* is a complete, orthonormal basis ofH, then
defines a measure preserving transformation, a rotation, onW. It is also shown that if for some strongly measurable, operator valued (onH) random variableR, (R(w+k)h) is (0, |h|
H
2
)-Gaussian for allk, hH, thenR is an isometry and Rh is quasi-nilpotent for allHH. The relation between the stochastic calculi for these Wiener pathsw and
, as well as the conditions of the inverbibility of the map
are discussed and the problem of the absolute continuity of the image of the Wiener measure under Euclidean motion on the Wiener space (i.e.
composed with a shift) is studied.The research of the second author was supported by the Fund for the Promotion of Research at the TechnionDedicated to the memory of Albert Badrikian 相似文献