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1.
Sjoerd E. Crans 《K-Theory》2003,28(1):39-105
Let
be n-dimensional teisi, i.e., higher-dimensional Gray-categorical structures. The following questions can be asked. Does a left q-transfor
, i.e., a functor 2
q
, induce a right q-transfor
, i.e., a functor
More generally, does a functor
induce a functor
For k-arrows c and
whose (k – 1)-sources and targets agree, does a q-transfor
induce a q-transfor
, for appropriate k-arrows
For k-arrows c and
whose (k – 1)-sources and targets agree, does a q-transfor
induce a (q + k + 1)-transfor
, for appropriate k-arrows
I give answers to these questions in the cases where n-dimensional teisi and their tensor product have been defined, i.e., for n 3, and for n up to 5 in some cases that do not need all data and axioms of n-dimensional teisi.I apply the above to compositions in teisi, in particular to braidings and syllepses. One of the results is that a braiding on a monoidal 2-category induces a pseudo-natural transformation
, where
is the reverse of ? –, which is almost, but not quite, equal to – ?. However, in higher dimensions need not be reversible, so a braiding on a higher-dimensional tas can not be seen as a transfor A B B A. 相似文献
2.
On automorphisms of split metacyclic groups 总被引:1,自引:0,他引:1
Let D(m, n; k) be the semi-direct product of two finite cyclic groups and , where the action is given by yxy
−1 = x
k
. In particular, this includes the dihedral groups D
2m
. We calculate the automorphism group Aut (D(m, n; k)). 相似文献
3.
Two Inequalities for Convex Functions 总被引:1,自引:0,他引:1
Let a 0 < a 1 < ··· < a n be positive integers with sums $ {\sum\nolimits_{i = 0}^n {\varepsilon _{i} a_{i} {\left( {\varepsilon _{i} = 0,1} \right)}} } Let a
0 < a
1 < ··· < a
n
be positive integers with sums
distinct.
P. Erd?s conjectured that
The best known result along this line is that
of Chen: Let f be any given convex decreasing function on [A, B] with α
0, α
1, ... , α
n
, β
0, β
1, ... , β
n
being real numbers in [A, B] with α
0 ≤ α
1 ≤ ··· ≤ α
n
,
Then
In this paper, we obtain two generalizations of the above result; each is of
special interest in itself. We prove:
Theorem 1
Let f and g be two given non-negative convex decreasing functions on [A, B], and α
0, α
1, ... ,
α
n
, β
0, β
1, ... , β
n
, α'
0, α'
1, ... , α'
n
, β'
0
, β'
1
, ... , β'
n
be real numbers in [A, B] with
α
0 ≤ α
1 ≤ ··· ≤
α
n
,
α'
0 ≤ α'
1 ≤ ··· ≤ α'
n
,
Then
Theorem 2
Let f be any given convex decreasing function on [A, B] with
k
0, k
1, ... , k
n
being nonnegative
real numbers and
α
0, α
1, ... , α
n
, β
0, β
1, ... , β
n
being real numbers in [A, B] with
α
0 ≤ α
1 ≤
··· ≤ α
n
,
Then
相似文献
4.
Thomas Geisser 《K-Theory》1997,12(3):193-226
We prove that for W2
the Witt vectors of length two over the finite field
, we have
in characteristic at least 5 and
for (3,f) = 1. The result is proved by using the identity
and calculating the right term with a group homology spectral sequence. Some information on the spectral sequence is achieved by using the action of the outer automorphism of SL on the homology groups and recent results on K-groups of local rings and the ring of dual numbers over finite fields. 相似文献
5.
Claude L. Schochet 《K-Theory》1998,14(2):197-199
In this note we correct a mistake in K-Theory 10 (1996), 49–72. In that paper we asserted that under bootstrap hypotheses the short exact sequence
which arises in the computation ofKK(A,B)
(is a split sequence. This is not always the case. ThusKK(A,B)
(decomposes into the three components
and
However, this is a decomposition in the sense of composition series, not as three direct summands. The same correction applies to the Milnor sequence. If there is no primepfor which bothK(A)
(andK(B)
*haveptorsion then the decomposition is indeed as direct summands. The other results of the paper are unaffected. 相似文献
6.
Philippe Gille 《K-Theory》2000,21(1):57-100
Let G/F be a semisimple algebraic group defined over a field F with characteristic
. Let us denote by
the Galois cohomology group introduced by Kato. If
, we show that the p-primary part of Rost's invariant
lifts in characteristic 0. This result allows to deduce properties of the Rost invariant in positive characteristic from known properties in characteristic 0. The case of Merkurjev–Suslin's invariant is specially interesting, i.e. if G/F=SL(D) for a central simple algebra D/F with degree p and class
, one has
and an element
is a reduced norm if and only if the cup-product
is trivial in
; one characterizes also in positive characteristic fields with p-dimension
by the surjectivity of reduced norms.In a second part, we study Rost invariants when the base field is complete for a discrete valuation. As planned by Serre, invariants are then linked with Bruhat–Tits' theory, this yields a new proof of their nontriviality. 相似文献
7.
8.
Shinji Azuma Kenji Hayashi Akio Kudô 《Annals of the Institute of Statistical Mathematics》1984,36(1):475-479
Summary Given two sets of sizek, {α
1...,α
k} and {β
1...,β
k} there arek! possible combinations of these two
, and suppose there is apriori given a number corresponding to the partnership (α
1,β
j}. The average of the numbers corresponding to
is a random variable, and this paper presents the first five moments of the average, and an application in the study of an
isolated human population is demonstrated. 相似文献
9.
Zhu Yaochen 《数学学报(英文版)》1988,4(4):364-371
Let
be a finitely generated extension field of ℚ, andα
i,βj(1⩽i⩽m,1⩽j⩽n) be some complex numbers. Let
(k=1,2,3) be fields obtained by adjoining to
the numbers {α
i,βj exp(αiβj)}, {αi, exp(αiβj)}, and {exp(αiβj)}, respectively. In the present note the relation between the transcendental degree of
over
and the transcendence type of
over ℚ is given.
This work was completed in Dpt. Math., Univ. of Southern Mississippi, Hattiesburg, USA. 相似文献
10.
Julia Weber 《Mathematische Zeitschrift》2007,256(1):57-74
We geometrically construct a homology theory that generalizes the Euler characteristic mod 2 to objects in the unoriented
cobordism ring of a topological space X. This homology theory Eh
* has coefficients in every nonnegative dimension. There exists a natural transformation that for X = pt assigns to each smooth manifold its Euler characteristic mod 2. The homology theory is constructed using cobordism of stratifolds,
which are singular objects defined below. An isomorphism of graded -modules is shown for any CW-complex X. For discrete groups G, we also define an equivariant version of the homology theory Eh
*, generalizing the equivariant Euler characteristic. 相似文献
11.
A. V. Bogomol'naya 《Journal of Mathematical Sciences》1995,73(6):633-637
We consider
,mE > 0,G(E) is a certain subspace of L
1
(E) consisting of functions concentrated on E and integrable, and {dk}, (k ∈ ℤ) in a summable sequence of positive numbers. It is proved that if G(E)=Lp(E), p≥2, then there exists f∈G(E) such that |f(n)|≥dn,
(one of the questions involved in the majorization problem). Sufficient conditions are obtained for certain other function
classes G(E). We study the question of partial majorization. Bibliography: 2 titles.
Translated fromProblemy Matematicheskogo Analiza, No. 13, 1992, pp. 42–48. 相似文献
12.
J. V. Manojlović 《Lithuanian Mathematical Journal》2009,49(1):71-92
We consider a class of fourth-order nonlinear difference equations of the form
where α and β are the ratios of odd positive integers, and {p
n
} and {q
n
} are positive real sequences defined for all
satisfying the condition
We classify the nonoscillatory solutions of (Ω) and establish necessary and/or sufficient conditions for the existence of
nonoscillatory solutions with specific asymptotic behavior.
Supported by Ministry of Science, Technology and Development of Republic of Serbia – Grant No. 144003. 相似文献
13.
Xi Mei WU Qin YUE 《数学学报(英文版)》2007,23(11):2061-2068
Let F = Q(√-p1p2) be an imaginary quadratic field with distinct primes p1 = p2 = 1 mod 8 and the Legendre symbol (p1/p2) = 1. Then the 8-rank of the class group of F is equal to 2 if and only Pl if the following conditions hold: (1) The quartic residue symbols (p1/p2)4 = (p2/p1)4 = 1; (2) Either both
p1 and p2 are represented by the form a^2 + 32b^2 over Z and p^h2+(2p1)/4=x^2-2p1y^2,x,y∈Z,or both p1 and p2 are not represented by the form a^2 + 32b^2 over Z and p^h2+(2p1)/4=ε(2x^2-p1y^2),x,y∈Z,ε∈{±1},where h+(2p1) is the narrow class number of Q(√2p1),Moreover, we also generalize these results. 相似文献
14.
Maximum nonlinear functions are widely used in cryptography because the coordinate functions F
β
(x) := tr(β
F(x)), , have large distance to linear functions. Moreover, maximum nonlinear functions have good differential properties, i.e.
the equations F(x + a) − F(x) = b, , have 0 or 2 solutions. Two classes of maximum nonlinear functions are the Gold power functions , gcd(k, m) = 1, and the Kasami power functions , gcd(k, m) = 1. The main results in this paper are: (1) We characterize the Gold power functions in terms of the distance of their
coordinate functions to characteristic functions of subspaces of codimension 2 in . (2) We determine the differential properties of the Kasami power functions if gcd(k,m) ≠ 1.
相似文献
15.
Jun Zhang 《Annals of the Institute of Statistical Mathematics》2007,59(1):161-170
The family of α-connections ∇(α) on a statistical manifold equipped with a pair of conjugate connections and is given as . Here, we develop an expression of curvature R
(α) for ∇(α) in relation to those for . Immediately evident from it is that ∇(α) is equiaffine for any when are dually flat, as previously observed in Takeuchi and Amari (IEEE Transactions on Information Theory 51:1011–1023, 2005). Other related formulae are also developed.
The work was conducted when the author was on sabbatical leave as a visiting research scientist at the Mathematical Neuroscience
Unit, RIKEN Brain Science Institute, Wako-shi, Saitama 351-0198, Japan. 相似文献
16.
Let Γ be an arithmetic lattice in an absolutely simple Lie group G with trivial centre. We prove that there exists an integer N ≥ 2, a subgroup Λ of finite index in Γ, and an action of Λ on
such that the pair (
) has property (T). If G has property (T), then so does
. If G is the adjoint group of Sp(n, 1), then
is a property (T) group satisfying the Baum–Connes conjecture. If Γ is an arithmetic lattice in SO(n, 1), then the associated von Neumann algebra
is a II1-factor in Popa’s class
. Elaborating on this result of Popa, we construct a countable family of pairwise nonstably isomorphic group II1-factors in the class
, all with trivial fundamental groups and with all L2-Betti numbers being zero.Mathematics Subject Classiffications (2000). 22E40, 22E47, 46L80, 37A20 相似文献
17.
Let {X k,i ; i ≥ 1, k ≥ 1} be a double array of nondegenerate i.i.d. random variables and let {p n ; n ≥ 1} be a sequence of positive integers such that n/p n is bounded away from 0 and ∞. In this paper we give the necessary and sufficient conditions for the asymptotic distribution of the largest entry ${L_{n}={\rm max}_{1\leq i < j\leq p_{n}}|\hat{\rho}^{(n)}_{i,j}|}$ of the sample correlation matrix ${{\bf {\Gamma}}_{n}=(\hat{\rho}_{i,j}^{(n)})_{1\leq i,j\leq p_{n}}}$ where ${\hat{\rho}^{(n)}_{i,j}}$ denotes the Pearson correlation coefficient between (X 1,i , ..., X n,i )′ and (X 1,j ,...,X n,j )′. Write ${F(x)= \mathbb{P}(|X_{1,1}|\leq x), x\geq0}$ , ${W_{c,n}={\rm max}_{1\leq i < j\leq p_{n}}|\sum_{k=1}^{n}(X_{k,i}-c)(X_{k,j}-c)|}$ , and ${W_{n}=W_{0,n},n\geq1,c\in(-\infty,\infty)}$ . Under the assumption that ${\mathbb{E}|X_{1,1}|^{2+\delta} < \infty}$ for some δ > 0, we show that the following six statements are equivalent: $$ {\bf (i)} \quad \lim_{n \to \infty} n^{2}\int\limits_{(n \log n)^{1/4}}^{\infty}\left( F^{n-1}(x) - F^{n-1}\left(\frac{\sqrt{n \log n}}{x}\right) \right) dF(x) = 0,$$ $$ {\bf (ii)}\quad n \mathbb{P}\left ( \max_{1 \leq i < j \leq n}|X_{1,i}X_{1,j} | \geq \sqrt{n \log n}\right ) \to 0 \quad{\rm as}\,n \to \infty,$$ $$ {\bf (iii)}\quad \frac{W_{\mu, n}}{\sqrt {n \log n}}\stackrel{\mathbb{P}}{\rightarrow} 2\sigma^{2},$$ $$ {\bf (iv)}\quad \left ( \frac{n}{\log n}\right )^{1/2} L_{n} \stackrel{\mathbb{P}}{\rightarrow} 2,$$ $$ {\bf (v)}\quad \lim_{n \rightarrow \infty}\mathbb{P}\left (\frac{W_{\mu, n}^{2}}{n \sigma^{4}} - a_{n}\leq t \right ) = \exp \left \{ - \frac{1}{\sqrt{8\pi}} e^{-t/2}\right \}, - \infty < t < \infty,$$ $$ {\bf (vi)}\quad \lim_{n \rightarrow \infty}\mathbb{P}\left (n L_{n}^{2} - a_{n}\leq t \right ) = \exp \left \{ - \frac{1}{\sqrt{8 \pi}} e^{-t/2}\right \}, - \infty < t < \infty$$ where ${\mu=\mathbb{E}X_{1,1}, \sigma^{2}=\mathbb{E}(X_{1,1} - \mu)^{2}}$ , and a n = 4 log p n ? log log p n . The equivalences between (i), (ii), (iii), and (v) assume that only ${\mathbb{E}X_{1,1}^{2} < \infty}$ . Weak laws of large numbers for W n and L n , n ≥ 1, are also established and these are of the form ${W_{n}/n^{\alpha}\stackrel{\mathbb{P}}{\rightarrow} 0}\,(\alpha > 1/2)$ and ${n^{1-\alpha}L_{n}\stackrel{\mathbb{P}}{\rightarrow} 0}\,(1/2 < \alpha \leq 1)$ , respectively. The current work thus provides weak limit analogues of the strong limit theorems of Li and Rosalsky as well as a necessary and sufficient condition for the asymptotic distribution of L n obtained by Jiang. Some open problems are also posed. 相似文献
18.
Let {S
k
, k ≥ 0} be a symmetric random walk on , and an independent random field of centered i.i.d. random variables with tail decay . We consider a random walk in random scenery, that is . We present asymptotics for the probability, over both randomness, that {X
n
> n
β} for β > 1/2 and α > 1. To obtain such asymptotics, we establish large deviations estimates for the self-intersection local
times process , where l
n
(x) is the number of visits of site x up to time n.
相似文献
19.
The main result of this work is a Dancer-type bifurcation result for the quasilinear elliptic problem
Here, Ω is a bounded domain in denotes the Dirichlet p-Laplacian on , and is a spectral parameter. Let μ1 denote the first (smallest) eigenvalue of −Δ
p
. Under some natural hypotheses on the perturbation function , we show that the trivial solution is a bifurcation point for problem (P) and, moreover, there are two distinct continua, and , consisting of nontrivial solutions to problem (P) which bifurcate from the set of trivial solutions at the bifurcation point (0, μ1). The continua and are either both unbounded in E, or else their intersection contains also a point other than (0, μ1). For the semilinear problem (P) (i.e., for p = 2) this is a classical result due to E. N. Dancer from 1974. We also provide an example of how the union looks like (for p > 2) in an interesting particular case.
Our proofs are based on very precise, local asymptotic analysis for λ near μ1 (for any 1 < p < ∞) which is combined with standard topological degree arguments from global bifurcation theory used in Dancer’s original
work.
Submitted: July 28, 2007. Accepted: November 8, 2007. 相似文献
((P)) |
20.
We consider two-phase metrics of the form ϕ(x, ξ) ≔
, where α,β are fixed positive constants and B
α, B
β are disjoint Borel sets whose union is ℝN, and prove that they are dense in the class of symmetric Finsler metrics ϕ satisfying
. Then we study the closure
of the class
of two-phase periodic metrics with prescribed volume fraction θ of the phase α. We give upper and lower bounds for the class
and localize the problem, generalizing the bounds to the non-periodic setting. Finally, we apply our results to study the
closure, in terms of Γ-convergence, of two-phase gradient-constraints in composites of the type f(x, ∇ u) ≤ C(x), with C(x) ∈ {α, β } for almost every x. 相似文献