共查询到20条相似文献,搜索用时 31 毫秒
1.
Arthur Moór 《Annali di Matematica Pura ed Applicata》1961,54(1):255-273
Zusammenfassung Das invariante Differential eines Vektors
ist selbst ein Vektor, der vom Orte xi, von dxi,
und von
selbst abh?ngig ist. Es wird nun infolge dieser Definition in einigen F?llen die m?gliche Form des invarianten Differentials
bestimmt.
Enrico Bompiani zu seinem wissenschaftlichen Jubil?um. 相似文献
2.
A. Belleni-Morante 《Annali di Matematica Pura ed Applicata》1976,108(1):85-95
Riassunto. Si studia un problema non lineare di trasporto di neutroni in un muro omogeneo con sezioni d'urto dipendenti dalla temperatura.
Facendo uso di alcune tecniche standard della teoria delle equazioni non lineari di evoluzione, si prova l'esistenza e l'unicità
di una soluzione forte u=u(t), per ogni t ∈ [0,
], ove
è scelto in modo opportuno. Infine, si indica un procedimento per determinare una funzione continua e non negativa b=b(t),
tale che ‖u(t)‖⩽b(t) per ogni t ∈ [0,
].
A Dario Graffi nel suo 70o compleanno
Entrata in Redazione il 15 marzo 1975. 相似文献
Summary We study a non-linear neutron transport problem in a homogeneous slab with temperature feedback. By using some standard techniques from the theory of non-linear evolution equations, we prove existence and uniqueness of a strong solution u=u(t) at any t ∈ [0, ]. Finally, we indicate a procedure to find a non-negative continuous b=b(t), such that ‖u(t)‖⩽b(t), at any t ∈ [0, ].
A Dario Graffi nel suo 70o compleanno
Entrata in Redazione il 15 marzo 1975. 相似文献
3.
Ida Cattaneo-Gasparini 《Annali di Matematica Pura ed Applicata》1963,63(1):133-150
Sunto Un campo di vettori
di una varietà riemanniana Vn+1 induce in essa mediante la decomposizione locale dello spazio tangente nel sottospazio parallelo a
e nel sottospazio ad esso normale e supplementare una particolare struttura quasi prodotto.
Vengono qui studiate le connessioni rispettanti tale struttura (connessioni vincolate) con particolare riguardo alla connessione
vincolata
canonicamente associata alla connessione riemanniana Γ.
Si danno semplici formule che legano la derivazione covariante secondo
alla derivazione covariante riemanniana.
Lavoro eseguito nell'ambito dell'attività del Gruppo di ricerca matematica No 1 del C. N. R. 相似文献
4.
Summary Quaternion generalized fiber bundles
are studied, both isomorphic to global tensorial product
ordinary quaternion fiber bundles right and left respectively) and quite general ones. A cohomology class
is considered which represents the obstruction in order the fiber bundle be a tensorial product. Several properties and a
splitting principle are proved for bundles
. On this ground and founding on a convenient bundle BE → X associated to jaz (that we call Bonan's bundle and for which ɛ(
=ɛ(BE)) relations are stated among Stiefel-Whitney classes of
, BE and the class ɛ.
Entrata in Redazione il 14 agosto 1974.
Lavoro eseguito con contributo del C.N.R., nell'ambito del Gruppo Nazionale per le Strutture Algebriche e Geometriche e loro Applicazioni. 相似文献
Entrata in Redazione il 14 agosto 1974.
Lavoro eseguito con contributo del C.N.R., nell'ambito del Gruppo Nazionale per le Strutture Algebriche e Geometriche e loro Applicazioni. 相似文献
5.
Summary The purpose of this paper is to study the validity of the Paley inequality on square function, for noncommutative martingales.
Let
be a regular gage space, and
a sequence of von-Neumann algebras such that
we prove that for every
, where ɛn(F) is the conditional expectation of F with respect to the subalgebra
: We also consider the case of a martingale arising in the context of harmonic analysis on noncommutative discrete groups,
in analogy to the theorem of R.E.A.C. Paley on Fourier-Walsh series.
Entrata in Redazione il 26 gennaio 1977.
Partially sponsored by C.N.R. 相似文献
6.
Summary Continuing the program initiated in the first paper of this series, representations of the Lie algebra
of the Poincaré group
are constructed by forming suitable direct integrals of representations of SL(2, C) and extending them to
by means of four additional momentum operators whose matrix elements are derived in a basis adapted to the direct integral
structure. The representations obtained here include Wigner’s representations with positive mass and spin
and Wigner’s representations with zero mass, spin
and helicity ±
.
Lavoro eseguito con contributo del C.N.R. nell’ambito dell’attività di ricerca del Gruppo Nazionale per la Fisica Matematica
e per le applicazioni della Matematica alla Fisica ed all’Ingegneria.
Entrata in Redazione il 12 marzo 1972. 相似文献
7.
Yasunori Fujikoshi Yoshimichi Ochi 《Annals of the Institute of Statistical Mathematics》1984,36(1):119-128
Summary In this paper we obtain an asymptotic expansion of the distribution of the maximum likelihood estimate (MLE)
based onT observations from the first order Gaussian process up to the term of orderT
−1. The expansion is used to compare
with a generalized estimate
including the least square estimate (LSE)
, based on the asymptotic probabilities around the true value of the estimates up to the terms of orderT
−1. It is shown that
(or the modified MLE
) is better than
(or the modified estimate
). Further, we note that
does not attain the bound for third order asymptotic median unbiased estimates. 相似文献
8.
LetW be an open Riemann surface and
ap-sheeted (1<p<∞) unlimited covering surface ofW. Denote by Δ1 (resp.,
) the minimal Martin boundary ofW (resp.,
). For ζ ∈ Δ, let
ζ be the (cardinal) number of the set of pionts
which lie over ζ and
the class of open connected subsetsM ofW such thatM∪{ζ} is a minimal fine neighborhood of ζ. Our main result is the following:
, where
is the number of components of π-1
M and π is the projection of
ontoW. Moreover, some applications of the above results are discussed whenW is the unit disc. 相似文献
9.
Kôichi Inada 《Annals of the Institute of Statistical Mathematics》1984,36(1):207-215
Summary This paper considers the problem of estimating a normal mean from the point of view of the estimation after preliminary test
of significance. But our point of view is different from the usual one. The difference is interpretation about a null hypothesis.
Let
denote the sample mean based on a sample of sizen from a normal population with unknown mean μ and known varianceσ
2. We consider the estimator that assumes the value
when
and the value
when
where ω is a real number such that 0≤ω≤1 andC is some positive constant. We prove the existence of ω, satisfying the minimax regret criterion and make a numerical comparison
among estimators by using the mean square error as a criterion of goodness of estimators. 相似文献
10.
N. Teodorescu 《Annali di Matematica Pura ed Applicata》1960,49(1):261-281
Résumé En définissant la notion de primitive aréolaire, on étudie à ce point de vue les fonctions holomorphes (α) et les fonctions
monogènes (α) introduites par l'auteur, ainsi que les sapports entre ces fonctions et les fonctions de la classe
et les
-primitives selon I. N. Vekua.
à Giovanni Sansone pour son 70me anniversaire. 相似文献
11.
Ryoichi Shimizu 《Annals of the Institute of Statistical Mathematics》1986,38(1):195-204
Summary LetX be a positive random variable with the survival function
and the densityf. LetX have the moments μ=E(X) and μ2=E(X
2) and put ε=|1-μ2/2μ2|. Put
and
. It is proved that the following inequalities hold:
, for allx>0, ifq(x) is monotone and that
, ifq
1
(x) is monotone. It is also shown that Brown's inequality
which holds wheneverq
1
(x) is increasing is not valid in general whenq
1 is decreasing.
The Institute of Statistical Mathematics 相似文献
12.
Giorgio Busetto 《Annali di Matematica Pura ed Applicata》1985,142(1):91-103
Sunto Siano G e
due gruppi, : GG una proiettività e N un sottogruppo normale di G. Vengono provati alcuni risultati sulle proprietà di immersions in
e G rispettivamente, del gruppi
, la chiusura normale di N in
modulo il nocciolo di N in
, e
.
Supported by a C.N.R. grant. 相似文献
Supported by a C.N.R. grant. 相似文献
13.
Wolfgang Henke 《manuscripta mathematica》1976,19(2):165-188
Let M, resp.
, denote Riemannian manifolds of dimensions m>4, resp.
=m+2, and of constant sectional curvatures C, resp.
, with
0 and
is a standard space form, then the foliation L is a (globally) trivial fibre bundle with fibre Sm–1. 相似文献
14.
Summary It is proved that every entropy with the property of branching has the form
, where J is a compositive information measure under a regular binary operation. In particular all the classical entropies
with the branching property such as that of Shannon have the form
.
Entrata in Redazione il 9 aprile 1973. 相似文献
Sunto Si dimostra che ogni entropia che goda della proprietà di diramazione ha necessariamente la forma dove J è una misura di informazione compositiva con una operazione binaria regolare. In particolare tutte le entropie classiche che godono della proprietà di diramazione quale quella di Shannon hanno la forma .
Entrata in Redazione il 9 aprile 1973. 相似文献
15.
V. R. Kogan 《Theoretical and Mathematical Physics》2000,122(3):380-389
We study the distribution of the distance R(t) between two Lagrangian trajectories in a spatially smooth turbulent velocity
field with an arbitrary correlation time and a non-Gaussian distribution. There are two dimensionless parameters, the degree
of deviation from the Gaussian distribution α and β=τD, where τ is the velocity correlation time and D is a characteristic
velocity gradient. Asymptotically, R(t) has a lognormal distribution characterized by the mean runaway velocity
and the dispersion Δ. We use the method of higher space dimensions d to estimate
and Δ for different values of α and β. It was shown previously that
for β≪ 1 and
for β≫ 1. The estimate of Δ is then nonuniversal and depends on details of the two-point velocity correlator. Higher-order
velocity correlators give an additional contribution to Δ estimated as αD2τ for β≪1 and αβ/τ for β≫1. For α above some critical value σcr, the values of
and Δ are determined by higher irreducible correlators of the velocity gradient, and our approach loses its applicability.
This critical value can be estimated as
for β≪1 and
for β≫1.
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 122, No. 3, pp. 456–467, March, 2000. 相似文献
16.
Zoé Chatzidakis 《Israel Journal of Mathematics》1986,55(2):173-183
LetK be a hilbertian field,G(K) its absolute Galois group. IfK is countable, then for a.a.
inG(K)
e
,
and there is no intermediate field
with
. Let
∈G(K)
e
. Then for a.a.
in
. 相似文献
17.
Let
and
be adjoint nilpotent orbits in a real semisimple Lie algebra. Write
≥
if
is contained in the closure of
. This defines a partial order on the set of such orbits, known as the closure ordering. We determine this order for the split
real form of the simple complex Lie algebra, E
8. The proof is based on the fact that the Kostant-Sekiguchi correspondence preserves the closure ordering. We also present
a comprehensive list of simple representatives of these orbits, and list the irreeducible components of the boundaries
and of the intersections
. 相似文献
18.
Summary Given two subspaces A0 ⊂ A1 ⊂ W=X ⊕ Y, where X, Y are Banach spaces, we show how to characterize, in terms of generalized boundary conditions, those
adjoint pairs A, A* satisfying A0 ⊂ A ⊂ A1, A
1
*
⊂ A∗ ⊂ A
0
*
⊂ W+=Y* ⊕ X*, where X*, Y* are the conjugate spaces of X, Y, respectively. The characterizations of selfadjoint (normal) subspace
extensions of symmetric (formally normal) subspaces appear as special cases when Y=X*. These results are then applied to ordinary
differential subspaces in W=Lq(ι) ⊕ Lr(ι), 1≦q, r≦∞, where τ is a real interval, and in W=C(
) ⊕ C(
), where
is a compact interval.
Entrata in Redazione il 21 febbraio 1977.
The work of EarlA. Coddington was supported in part by the National Science Foundation under NSF Grant No. MCS-76-05855. 相似文献
19.
Summary We study the problem of the existence of bounded solutions for the equation
on pseudo-Siegel domains
when the data
satisfies the condition
.
Work done within the Project 40% M.U.R.S.T. «Geometria Reale e Complessa». 相似文献
Sunto Si studia il problema dell'esistenza di soluzioni limitate per l'equazione sui domini pseudo-Siegel quando il dato soddisfa alla condizione .
Work done within the Project 40% M.U.R.S.T. «Geometria Reale e Complessa». 相似文献
20.
Cesarina Marchionna Tibiletti 《Annali di Matematica Pura ed Applicata》1978,44(1):251-259
Sunto Dati due gruppi A* e B* e due loro sottogruppi I
A
*
ed I
B
*
fra loro isomorfi in un certo isomorfismo ω si considerano i gruppi G=AB con A e B permutabili fra di loro ed isomorfi rispettivamente
ad A* e B* in modo che I=A∩B sia isomorfo ed I*A ed I*B. Si caratterizzano, in base alla struttura dei gruppi dati, certi gruppi prodotto completo
nei quali sono contenuti (come sottogruppi di tipo ben definito) i suddetti gruppi G=AB (e ciò sotto alcune ipotesi per A*
e B*, che valgono sempre quando A* e B* sono gruppi finiti). Si illustra poi qualche caso in cui i precedenti gruppi
risultano prodotti completi minimi in cui siano contenuti i gruppi G=AB. 相似文献