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1.
Let G be a connected graph. For at distance 2, we define , and , if then . G is quasi-claw-free if it satisfies , and G is P
3-dominated() if it satisfies , for every pair (x, y) of vertices at distance 2. Certainly contains as a subclass. In this paper, we prove that the circumference of a 2-connected P
3-dominated graph G on n vertices is at least min or , moreover if then G is hamiltonian or , where is a class of 2-connected nonhamiltonian graphs. 相似文献
2.
Let m ≥ 1 be an integer and N > 2m. Let μ be a positive Radon measure on . We study necessary and sufficient conditions on possible distributional solutions of , that guarantee the validity of the representation formula a.e. on , where and c(2m) is a positive constant depending on m and N. Several consequences are derived. In particular we prove Liouville theorems for systems of higher order elliptic inequalities
and weighted form of Hardy-Littlewood-Sobolev systems of integral equations.
Received: March 2008 相似文献
3.
Let be a Radon measure on
which may be non-doubling. The only condition that must satisfy is
for all
and for some fixed
In this paper, under this assumption, the Lp()-boundedness (1 < p < ) and certain weak type endpoint estimate are established for multilinear commutators, which are generated by Calderón-Zygmund singular integrals with RBMO() functions or with
functions for r 1, where
is a space of Orlicz type satisfying that
if r = 1 and
if r > 1. 相似文献
4.
On the atomic conditions of lattice-ordered groups 总被引:2,自引:0,他引:2
We introduce large convex
-subgroups to study the structure of the lattice-ordered groups
G whose C(G), P(G) and (G) satisfy atomic conditions, where C(G), P(G) and (G) denote respectively the lattice of all convex
-subgroups, the lattice of all polar subgroups and the root system of all regular subgroups of G. In particular, we construct a new torsion class
defined as the class of
-groups G for which all large prime subgroups are maximal. We prove that the class of hyperarchimedean
-groups is properly contained within
and that any
-group within
has the property that any chain of prime subgroups has length at most 2.Received October 7, 2003; accepted in final form June 11, 2004. 相似文献
5.
W. Hazod 《Probability Theory and Related Fields》1971,20(4):259-270
Ohne ZusammenfassungBezeichnungen und Symbole
G
lokalkompakte topologische Gruppe
-
M(G)/R(G)/P(G)/
regulÄre komplexe/reelle/positive Ma\e/
-
Q(G)/W(G)
Ma\e mit · l/Wahrscheinlichkeitsma\e
-
x
Punktma\:
x(f)=f(x)
-
v
Faltung,
— Bekanntlich bildet M(G) bezüglich der Faltung eine Banachalgebra;
-
Involution in M(G),
, wobei — die Komplexkonjugierte bezeichnet
- ×
diskreter Anteil eines Ma\es,
-
T
gm
Faltungsoperator auf L
2 (G) (bezüglich des linken Haarschen Ma\es),
f.ü.
-
p(·)/q(·)/u(·)
- exp(·.)
Exponentialfunktion, exp
- normal/unitÄr/symmetrisch/positiv definit
bezeichnet man ein Ma\ , wenn der Faltungsoperator T
diese Eigenschaft besitzt
- invertierbar
hei\t
M(G), wenn ein vM(G) existiert, so da\ v = v=
e
-
1/n
n-te Wurzel von
1
hei\t wenn(
1/n)n=
1
-
1 hei\t unendlich teilbar
wenn zu jedem natürlichen n eine n-te Wurzel
1/n von existiert
-
N
Menge der natürlichen Zahlen 相似文献
6.
A. V. Vasilyev 《Algebra and Logic》2002,41(2):74-80
It is proved that a finite group that is isomorphic to a simple non-Abelian group G=G
2(3
n
) is, up to isomorphism, recognized by a set (G) of its element orders, that is, H G if (H)=(G) for some finite group H. 相似文献
7.
Finite groups with minimal 1-PIM 总被引:1,自引:0,他引:1
Let be a field of characteristic and let G be a finite group. It is well-known that the dimension of the minimal projective cover (the so-called 1-PIM) of the trivial left -module is a multiple of the -part of the order of G. In this note we study finite groups G satisfying . In particular, we classify the non-abelian finite simple groups G and primes satisfying this identity (Theorem A). As a consequence we show that finite soluble groups are precisely those finite groups
which satisfy this identity for all prime numbers (Corollary B). Another consequence is the fact that the validity of this identity for a finite group G and for a small prime number implies the existence of an -Hall subgroup for G (Theorem C). An important tool in our proofs is the super-multiplicativity of the dimension of the 1-PIM over short exact
sequences (Proposition 2.2). 相似文献
8.
Mario Petrich 《Annali di Matematica Pura ed Applicata》2008,187(1):119-136
We construct a family of completely regular semigroups with the property that each completely regular semigroup S with a finite number of -classes in each -class is non-cryptic if and only if S contains an isomorphic image of a member of . Each member F of is an ideal extension of a Rees matrix semigroup J by a cyclic group B with a zero adjoined and the identity of B is the identity of F. Here with I and Λ finite, G is given by generators and relations, and P is given explicitly. Within completely regular semigroups, the cryptic property is equivalent to where is the natural partial order and a
if and only if a
2 = ab = ba. Hence the above result can be formulated in terms of and .
相似文献
9.
Let be a finite field with q elements, where q is a prime power. Let G be a subgroup of the general linear group over and be the rational function field over . We seek to understand the structure of the rational invariant subfield . In this paper, we prove that is rational (or, purely transcendental) by giving an explicit set of generators when G is the symplectic group. In particular, the set of generators we gave satisfies the Dickson property.
相似文献
10.
Aparna W. Higgins 《Algebra Universalis》1985,20(2):179-193
Given a group G and a descending chainG
0,G
1,...,G
n, of normal subgroups ofG, we prove that there exists a universal algebra
, such that the chain ...Wn(
)...W1(
}) W0(
)W(
) is isomorphic to the chain ...G
n ...G
1G
0G, where W(
) is the group of weak automorphisms of
, and Wn(
) is the group of weak automorphisms of
that leaves alln-ary operations fixed.We also prove that there are an infinite number of non-isomorphic algebras that satisfy the above.These results are a generalization of those proved by J. Sichler, in the special case when G=G0, and G1=G2=...=Gn=....Presented by J. Mycielski.This paper comprises part of the author's doctoral dissertation at the University of Notre Dame in 1983. The author wishes to express her deep gratitude to Professor Abraham Goetz for suggesting this problem, for being extremely generous with his time and experience, and for giving her his constant encouragement. The author also thanks the reviewer for his helpful comments. 相似文献
11.
In the present paper we suggest an explicit construction of a Cartan connection for an elliptic or hyperbolic CR manifold
M of dimension six and codimension two, i.e. a pair
, consisting of a principal bundle
over M and of a Cartan connection form
over P, satisfying the following property: the (local) CR transformations
are in one to one correspondence with the (local) automorphisms
for which
. For any
, this construction determines an explicit monomorphism of the stability subalgebra Lie (Aut(M)x) into the Lie algebra
of the structure group H of P.
Mathematics Subject Classification (2000) Primary 32V05, Secondary 53C15, 53A55 相似文献
12.
Andreia Hall 《Extremes》2001,4(3):219-239
In this paper we study the limiting distribution of the maximum term of non-negative integer-valued moving average sequences of the form X
n =
i = –
i Z
n – i
where { Z
n} is an iid sequence of non-negative integer-valued random variables with regularly varying tails,
iZ
n–i denotes binomial thinning. Several models are considered allowing different dependence structures on the thinning operations. For these models we manage to establish results which are similar to the ones obtained for the classic linear moving average: { X
n} > has an extremal index = \maxi{
i
} / (
i
), where is the index of regular variation, irrespectively of the dependence structure considered. The paper is concluded with a simulation study to illustrate the results. 相似文献
13.
LetX, Y be finite sets and suppose thatF is a collection of pairs of sets (F, G),FX,GY satisfying |FF|s, |GG|t and |FF|+|GG|s+t+1 for all (F, G),F, GF. Extending a result of Sali, we determine the maximum ofF. 相似文献
14.
Let be a Fuchsian group of genus at least 2 (at least 3 if is non-oriented). We study the spaces of homomorphisms from to finite simple groups G, and derive a number of applications concerning random generation and representation varieties. Precise asymptotic estimates for |Hom(,G)| are given, implying in particular that as the rank of G tends to infinity, this is of the form |G|()+1+o(1), where () is the measure of . We then prove that a randomly chosen homomorphism from to G is surjective with probability tending to 1 as |G|. Combining our results with Lang-Weil estimates from algebraic geometry, we obtain the dimensions of the representation varieties
, where
is GLn(K) or a simple algebraic group over K, an algebraically closed field of arbitrary characteristic. A key ingredient of our approach is character theory, involving the study of the zeta function G(s)=(1)-s, where the sum is over all irreducible complex characters of G. 相似文献
15.
We present a new method to show concentration of the upper tail of random variables that can be written as sums of variables with plenty of independence. We compare our method with the martingale method by Kim and Vu, which often leads to similar results.Some applications are given to the number X
G
of copies of a graph G in the random graph
(n,p). In particular, for G = K
4 and G = C
4 we improve the earlier known upper bounds on —ln (X
G
2
X
G
) in some range of p = p(n).* Research of the second author supported by KBN grants 2 P03A 032 16 and 2 P03A 015 23. 相似文献
16.
Let u(x) xR
q
be a symmetric nonnegative definite function which is bounded outside of all neighborhoods of zero but which may have u(0)=. Let p
x, (·) be the density of an R
q
valued canonical normal random variable with mean x and variance and let {G
x, ; (x, )R
q
×[0,1 ]} be the mean zero Gaussian process with covariance
A finite positive measure on R
q
is said to be in
with respect to u, if
When
, a multiple Wick product chaos
is defined to be the limit in L
2, as 0, of
where
,
denotes the Wick product of the m
j
normal random variables
.Consider also the associated decoupled chaos processes
,
defined as the limit in L
2, as 0, of
where
are independent copies of G
x,.Define
Note that a neighborhood of the diagonals of
in
is excluded, except those points on the diagonal which originate in the same Wick product in (i). Set
One of the main results of this paper is:
Theorem A. If
is continuous on (R
q
)
r
for all
then
is continuous on
.When u satisfies some regularity conditions simple sufficient conditions are obtained for the continuity of
on (R
q
)
r
. Also several variants of (i) are considered and related to different types of decoupled processes. These results have applications in the study of intersections of Lévy process and continuous additive functionals of several Lévy processes. 相似文献
17.
Let (G,
) denote a finite groupG with fibration
. The group Aut (G,
) of operators of (G,
) is closely related to the group of collineations of (G,
). In this paper we investigate the geometric properties imposed on (G,
) by requiring that Aut (G,
)=AutG. We find that in many instances this algebraic property restricts the geometry to a very special form.Dedicated to Professor Helmut Karzel on the occasion of his 60th birthday. 相似文献
18.
A measure-theoretic approach to the central limit problem for noncommutative infinitesimal arrays of random variables taking values in a Lie group G is given. Starting with an array
of probability measures on G and instance 0st one forms the finite convolution products
. The authors establish sufficient conditions in terms of Lévy-Hunt characteristics for the sequence
to converge towards a convolution hemigroup (generalized semigroup) of measures on G which turns out to be of bounded variation. In particular, conditions are stated that force the limiting hemigroup to be a diffusion hemigroup. The method applied in the proofs is based on properly chosen spaces of difierentiable functions and on the solution of weak backward evolution equations on G. 相似文献
19.
LetF be an algebraic number field and F such thatx
m– is irreducible, wherem is an integer. Let
be a prime ideal inF with
. The prime decomposition of
in
is explicitly obtained in the following cases. Case 1:
, (a,m) = 1 (where
means
, 0
). Case 2:m lt, wherel is a prime andl 0
. Case 3:m 0
and every prime that dividesm also dividespf–1. It is not assumed that thev
th roots of unity are inF for anyv 2. 相似文献
20.
John K. McVey 《Archiv der Mathematik》2005,84(6):481-484
When G is a finite nonabelian group, we associate the common-divisor graph (G) with G by letting nontrivial degrees in cd(G) be the vertices and making distinct vertices adjacent if they have a common nontrivial divisor. A set
of vertices for this graph is said to be strongly connective for cd(G) if there is some prime which divides every member of
and every vertex outside of
is adjacent to some member of
When G has a nonabelian solvable quotient, we show that if (G) is connected and has a diameter of at most 2, then indeed cd(G) has a strongly connective subset.Received: 7 July 2004; revised: 5 October 2004 相似文献