共查询到20条相似文献,搜索用时 109 毫秒
1.
We present an algorithm to compute the number ofF q -rational points on elliptic curves defined over a finite fieldF q , withj-invariant 0 or 1728. This algorithm takesO(log3 p) bit operations, werep is the characteristic ofF q . 相似文献
2.
Fix integers r,d,s,π with r≥4, d?s, r?1≤s≤2r?4, and π≥0. Refining classical results for the genus of a projective curve, we exhibit a sharp upper bound for the arithmetic genus p a (C) of an integral projective curve C?? r of degree d, assuming that C is not contained in any surface of degree <s, and not contained in any surface of degree s with sectional genus >π. Next we discuss other types of bound for p a (C), involving conditions on the entire Hilbert polynomial of the integral surfaces on which C may lie. 相似文献
3.
Nicolae Dinculeanu 《Rendiconti del Circolo Matematico di Palermo》1925,49(2):259-306
In this paper we define the stochastic integral for two parameter processes with values in a Banach spaceE. We use a measure theoretic approach. To each two parameter processX withX st ∈L E p we associate a measureI X with values inL E p . IfX isp-summable, i.e. ifI X can be extended to aσ-additive measure with finite semivariation on theσ-algebra of predictable sets, then the integralε HdI X can be defined and the stochastic integral is defined by (H·X) z =ε [0,z] HdI X . We prove that the processes with finite variation and the processes with finite semivariation are summable and their stochastic integral can be computed pathwise, as a Stieltjes Integral of a special type. 相似文献
4.
Sérgio M. Alves Fernanda G. de Paula Marcello Fidelis 《Rendiconti del Circolo Matematico di Palermo》1937,61(1):117-122
In this paper we calculate the Gelfand–Kirillov dimension of the relatively free (also called universal) algebra of rank m, U m (M a,b (E)?E), in the variety generated by M a,b (E)?E, in positive characteristic p>2. 相似文献
5.
Dimitre Tzigantchev 《Rendiconti del Circolo Matematico di Palermo》1925,49(2):221-228
LetR s be the subalgebra ofM 2(K[t]/(t s )) generated bye 11,e 22,te 12 andte 21, whereK is a field of characteristic 0,K[t] is the polynomial algebra in one variablet and (t s ) is the principal ideal inK[t], generated byt s . The main result of this paper is that we have described theT-idealT(R s ). Besides the two matrix polynomial identities — the standart identityS 4 and the identity of Hall, thisT-ideal is generated by one more explicitly given identity. The algebrasR s are interesting due to the fact that the proper identities of any subvarietyu of the variety ?=varM 2(K), generated by the matrix algebraM 2(K) of second order overK, asymptoticaly coincide with the proper identities of someR s . 相似文献
6.
An elementary proof of the (known) fact that each element of the Banach space? w p (X) of weakly absolutelyp-summable sequences (if 1≤p<∞) in the Banach spaceX is the norm limit of its sections if and only if each element of? w p (X) is a norm null sequence inX, is given. Little modification to this proof leads to a similar result for a family of Orlicz sequence spaces. Some applications to spaces of compact operators on Banach sequence spaces are considered. 相似文献
7.
M. T. Heydari 《Rendiconti del Circolo Matematico di Palermo》1936,60(1-2):139-143
Let K be a compact convex subset of the plane, μ be a regular Borel measure with support K and N μ be the multiplication operator on L 2(μ). In this article we show that \(\overline{W}(N_{\mu})\), the closure of numerical range of N μ , is K. Also we prove that if K has uncountable many extreme points then the Berberian Hilbert space extension of L 2(μ) is non separable. 相似文献
8.
Given a closed operatorA acting in a Banach spaceX, we define the regular (respectively the essentialy regular) spectrum σ r (A) (respectively σ e,r (A)) ofA. We prove that σ r (A) and σ e,r (A) are a closed subsets of the classical spectrum σ(A) ofA. Morever ifA is bounded we prove that σ r (A) and σ e,r (A)) satisfies the spectral mapping theorem. 相似文献
9.
A. D. Forbes M. J. Grannell T. S. Griggs 《Rendiconti del Circolo Matematico di Palermo》1932,56(1):17-32
In [8], Quattrochi and Rinaldi introduced the idea ofn ?1-isomorphism between Steiner systems. In this paper we study this concept in the context of Steiner triple systems. The main result is that for any positive integerN, there existsv 0(N) such that for all admissiblev≥v 0(N) and for each STS(v) (sayS), there exists an STS(v) (sayS′) such that for somen>N, S is strictlyn ?1-isomorphic toS′. We also prove that for all admissiblev≥13, there exist two STS(v)s which are strictly 2?1-isomorphic. Define the distance between two Steiner triple systemsS andS′ of the same order to be the minimum volume of a tradeT which transformsS into a system isomorphic toS′. We determine the distance between any two Steiner triple systems of order 15 and, further, give a complete classification of strictly 2?1-isomorphic and 3?1-isomorphic pairs of STS(15)s. 相似文献
10.
Tommaso Gentile Paolo A. Oliverio Francesco Polizzi 《Rendiconti del Circolo Matematico di Palermo》1937,61(1):19-46
We consider minimal surfaces of general type with p g =2, q=1 and K 2=5. We provide a stratification of the corresponding moduli space \(\mathcal{M}\) and we give some bounds for the number and the dimensions of its irreducible components. 相似文献
11.
Federico Bartolozzi 《Rendiconti del Circolo Matematico di Palermo》1921,45(1):105-115
In this paper we consider some questions concerning unitary spaces (V, h), even though (V, h) is not finitely generated. Our main result is as follows: letF be an infinite field of characteristic ≠2 andD anm 2-dimensional central division algebra overF with an involutionj≠1. Let Σj(D) denote the subgroup of the multiplicative groupD * generated by the non zero symmetric elements. If (V, h) is an infinite dimensional regular unitary space of Witt index at least two overD, then the finitary unitary groupFU(h) is a simple group if and only ifD*=Σj(D)[D*, D*]. On the other hand, when (V, h) is not regular,FU(h) cannot be simple since it containsFU 0(h), the subgroup of elements ofFU(h) acting trivially onrad(V, h), as a normal subgroup. In the non regular case we show that under the above assumptions evenFU 0(h) is not a simple group. 相似文献
12.
J. Naumann 《Rendiconti del Circolo Matematico di Palermo》1923,47(3):409-430
We consider weak solutions to the parabolic system ?u i?t?D α A i α (?u)=B i(?u) in (i=1,...,) (Q=Ω×(0,T), R n a domain), where the functionsB i may have a quadratic growth. Under the assumptionsn≤2 and ?u ?L loc 4+δ (Q; R nN ) (δ>0) we prove that ?u is locally Hölder continuous inQ. 相似文献
13.
Jarosław Górnicki 《Rendiconti del Circolo Matematico di Palermo》1922,46(1):89-118
In this paper we study in Banach spaces the existence of fixed points of (nonlinear) asymptotically regular semigroups. We establish for these semigroups some fixed point theorems in spaces with weak uniform normal structure, in a Hilbert space, inL p spaces, in Hardy spacesH p and in Sobolev spacesW r.p for 1<p<∞ andr≥0, in spaces with Lifshitz’s constant greater than one. These results are the generalizations of [8, 10, 16]. 相似文献
14.
Let ?1(a,b) be a regular lattice with the fundamental cell a rectangle with sides a,b, let ?2(a,b,?) be a regular lattice with the fundamental cell a parallelogram with sides a,b and angle ? and let ?3(a,b,c) be a regular lattice with the fundamental cell \(C_{0}^{( 3) }\) as in Fig. 7. In this paper we compute the probability that a random rectangle r of constant side l,m intersects a side of the lattice. In particular when the rectangle r becomes a segment of length l, (m=0) we obtain the Laplace probability. 相似文献
15.
M. Cristina Ronconi 《Rendiconti del Circolo Matematico di Palermo》1937,61(2):241-260
The known examples of nonsingular complex projective threefolds of general type with geometric genus p g =0 and irregularities q 1=q 2=0 have bigenus P 2≤6. In the present paper nonsingular threefolds with p g =q 1=q 2=0 and P 2=7 or P 2=8 are constructed. 相似文献
16.
Marco Reni 《Rendiconti del Circolo Matematico di Palermo》1922,46(1):71-88
We classify cyclic actions on compression bodies. We find necessary and sufficient arithmetic conditions for a compression body to admit aZ p -action withp a prime number. 相似文献
17.
Josep M. Miret 《Rendiconti del Circolo Matematico di Palermo》1925,49(1):61-74
We give a compactification of the varietyU of non-degenerate plane cuspidal cubics of ?3. We construct this compactification by means of the projective bundleX of a suitable vector bundleE. We describe the intersection ring ofX and, as a consequence, we obtain the intersection numbers ofU that satisfy 10 conditions of the following kinds:ρ, that the plane determined by the cuspidal cubic go through a point;c, that the cusp be on a plane;q, that the cuspidal tangent intersect a line;μ, that the cuspidal cubic intersect a line. Moreover, we prove that the Picard group of the varietyU is a product of two infinite cyclic groups generated byρ andc?q. 相似文献
18.
Letj vk ′ denotes thekth positive zero of the derivativeJ v ′ (x)=dJ v (x)/dx of Bessel functionJ v (x) fork=1, 2,…. We establish the upper bound
$$j'_{\nu k}< \nu + a_k \left( {\nu + \frac{{{\rm A}_k^3 }}{{a_k^3 }}} \right)^{\frac{1}{3}} + \frac{3}{{10}}a_k^2 \left( {\nu + \frac{{A_k^3 }}{{a_k^3 }}} \right)^{\frac{1}{3}} , \nu \geqslant 0, k = 1,2, \ldots $$ 相似文献
19.
Elżbieta Wagner-Bojakowska Władysław Wilczyński 《Rendiconti del Circolo Matematico di Palermo》1925,49(1):5-26
We prove that for an arbitrary setA ? ? its interior in aψ-density topology equalsA ∩ φβ(B), whereB is a measurable kernel ofA andβ is some countable ordinal. Moreover, eachβ, 1≤β<Ω, realizes the interior ofA for someA εS. 相似文献
20.
LetA be a commutative Banach algebra with unit. Denote byX A, the global spectrum ofA. There is a holomorphic functional calculusθ A:O(X A)→A such thatθ A(â)=a. In this paper, we show the uniqueness of the global holomorphic functional calculus and we establish its compatibility with Banach algebra morphisms. We also extend this holomorphic functional calculus to the case ofImc algebras. 相似文献