共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
Buchin Su 《Annali di Matematica Pura ed Applicata》1940,19(1):289-313
Sunto. The paper deals with many projective properties of the neighbourhoods of the third,4th, 5th order of a point on a non-holonome surfaceV
3
2
inS
3. Chiefly two remarkable projective correspondences are studied, between the tangent plane and the bundle of directions, with
his contact point as centre. Many generalizations are obtained of geometrical loci (so as lines, planes, quadrics) projectively
associated with the neighbourhoods of a point on an ordinary (holonome) surface. The last sections are concerned with the
extension to theV
3
2
of the quadric ofMoutard and theSegre's correspondence.
相似文献
3.
Manfred Peter 《Monatshefte für Mathematik》1996,121(4):335-352
Lattice points below Algebraic Curves. A generalization of the classical circle problem is treated. An asymptotic formula for the number of lattice points in a region whose boundary is an algebraic curve is obtained. This gives a mean value formula for the number of representations of the positive integers in the formn=g(x,y), whereg is a polynomial with coefficients 0 and leading terma
d0xd*a0dyd. The caseg(x,y)=p1(x)+p2(y) was considered inKuba andNowak [4], andKuba [5]. The discrete Hardy-Littlewood method is used along with Rouché's theorem. 相似文献
4.
D. V. Widder 《Annali di Matematica Pura ed Applicata》1956,42(1):279-305
Summary Relations between such transcendental differential operators asexp tD
x
2
andexp xD
t
1/2
are obtained. A new characterization of temperature functions represented by the classicalPoisson integral is obtained, as well as one for positive temperature functions. 相似文献
5.
El Maati Ouhabaz 《Semigroup Forum》1998,57(3):305-314
m
σ/|α|=|β|=m Dα(a
αβDβ) is a higher order degenerate-elliptic operator on L2(RN) and V ∈ L1(RN) we show in particular that s(λ) > 0 for all λ > 0 provided that ∫RN V(x)dx≥ 0, V not equivalent to 0 and N ≤ 2m. 相似文献
6.
Luigi Gatteschi 《Annali di Matematica Pura ed Applicata》1955,38(1):267-280
Sunto Partendo da una rappresentazione integrale delle funzioni diHankel H
v
(1)
(v) e H
v
(2)
(v) e facendo uso della teoria delle serie inviluppanti diJ. G. van der Corput si perviene ad uno sviluppo asintotico delle funzioni diBessel Jv(v) e Yv(v) e si valuta il termine complementare di tale sviluppo.
Summary From an integral rapresentation of theHankel functions H v (1) (v) and H v (2) (v) and by usingvan der Corput's theory of enveloping series we obtain an asymptotic expansion forBessel functions Jv(v) and Yv(v). An upper bound for the error term is also obtained.相似文献
7.
By an ω1-tree we mean a tree of power ω1 and height ω1. We call an ω1-tree a Jech-Kunen tree if it hask-many branches for somek strictly between ω1 and 2ω1. In this paper we construct the models of CH plus 2ω1 > ω2, in which there are Jech-Kunen trees and there are no Kurepa trees.
The research of the first author was partially supported by the Basic Research Fund, Israeli Academy of Science, Publ. No.
466. 相似文献
8.
Jean-Pierre Levinski 《Israel Journal of Mathematics》1984,48(2-3):225-243
We consider various forms of the Conjecture of Chang. Part A constitutes an introduction. Donder and Koepke have shown that
if ρ is a cardinal such that ρ ≧ ω1, and (ρ++,ρ+↠(ρ+, ρ), then 0+ exists. We obtain the same conclusion in Part B starting from some other forms of the transfer hypothesis. As typical corollaries,
we get:
Theorem A.Assume that there exists cardinals λ, κ, such that λ ≧
K
+ ≧ω2 and (λ+, λ)↠(K
+,K. Then 0+ exists.
Theorem B.Assume that there exists a singularcardinal κ such that(K
+,K↠(ω1, ω0. Then 0+ exists.
Theorem C.Assume that (λ
++, λ). Then 0+ exists (also ifK=ω
0.
Remark. Here, as in the paper of Donder and Koepke, “O+ exists” is a matter of saying that the hypothesis is strictly stronger than “L(μ) exists”. Of course, the same proof could give a few more sharps overL(μ), but the interest is in expecting more cardinals, coming from a larger core model.
Theorem D.Assume that (λ
++, λ)↠(K
+, K) and thatK≧ω
1. Then 0+ exists.
Remark 2. Theorem B is, as is well-known, false if the hypothesis “κ is singular” is removed, even if we assume thatK≧ω
2, or that κ is inaccessible. We shall recall this in due place.
Comments. Theorem B and Remark 2 suggest we seek the consistency of the hypothesis of the form:K
+, K↠(ωn +1, ωn), for κ singular andn≧0. 0266 0152 V 3
The consistency of several statements of this sort—a prototype of which is (N
ω+1,N
ω)↠(ω1, ω0) —have been established, starting with an hypothesis slightly stronger than: “there exists a huge cardinal”, but much weaker
than: “there exists a 2-huge cardinal”. These results will be published in a joint paper by M. Magidor, S. Shelah, and the
author of the present paper. 相似文献
9.
Werner-Georg Nowak 《Monatshefte für Mathematik》1982,94(2):143-147
LetG
2 (R) denote the number of lattice points (x, y) (i. e. points of the plane with integer coordinates) in the domainx
a
+y
a
R,x0,y0 (with weight 1/2 ifxy=0) and letV
2
(a)R
2/a
be the area of this region. Then for 0<a<1/3 it is known [2] thatG
2
(R)–V
2
(a)R
2/a
K(a)R
(1/a)–1
. Combining a method due toBleicher andKnopp [1] with a result proved elsewhere [4], [5] by the author it is shown here thatG
2
(R)=V
2
(a)R
2/a
+(R
(1/a)–1
) for any fixed rational numbera with 1/3<a<1/2. 相似文献
10.
Summary Two previous papers (in Vol. V) describe theory and some applications of the quotient-difference (=QD-) algorithm. Here we give an extension which allows the determination of the eigenvectors of a matrix. Letx
(0)
1
, ...,x
(0)
n
be a coordinate system in whichA has Jacobi form (such a system may be constructed with methods ofC. Lanczos orW. Givens). Then the QD-algorithm allows the construction of a sequence of coordinate systemsx
(2)
1
, ...,x
(2)
n
, (=0, 1, 2, ...) which converge for to the system of the eigenvectors ofA. 相似文献
11.
Sopra un principio di trasformazione integrale dei problemi differenziali ed alcune sue applicazioni
Guido Ascoli 《Annali di Matematica Pura ed Applicata》1955,40(1):167-182
Sunto Sviluppando ampiamente un'idea diWhittaker, si studiano trasformazioni del tipo
che mutano le soluzioni di una equazione differenziale lineareL
tx+λM
tx=0, appartenenti ad una classe lineare (G), opportunamente precisata, in soluzioni di una seconda equazione differenzialeP
uy+λQ
uy=0, appartenenti ad un'altra classe lineare (Γ). Il primo problema si suppone autoaggiunto. Il nucleo K è una soluzione dell'equazione
(L
t
Q
u −M
t
P
u)K=0, di classe (G) come funzione di t, di classe (Γ) come funzione di u. Il procedimento permette di stabilire proprietà
integrali in base a sole verifiche qualitative; ne vengono fatte applicazioni alle funzioni diMathieue diBessele ai polinomi diLegendree diHermite.
A Mauro Picone nel suo 70mo compleanno. 相似文献
12.
Jean Ludwig 《Monatshefte für Mathematik》1986,101(2):159-165
We say that a locally compact groupG hasT
1 primitive ideal space if the groupC
*-algebra,C
*(G), has the property that every primitive ideal (i.e. kernel of an irreducible representation) is closed in the hull-kernel topology on the space of primitive ideals ofC
*(G), denoted by PrimG. This means of course that every primitive ideal inC
*(G) is maximal. Long agoDixmier proved that every connected nilpotent Lie group hasT
1 primitive ideal space. More recentlyPoguntke showed that discrete nilpotent groups haveT
1 primitive ideal space and a few month agoCarey andMoran proved the same property for second countable locally compact groups having a compactly generated open normal subgroup. In this note we combine the methods used in [3] with some ideas in [9] and show that for nilpotent locally compact groupsG, having a compactly generated open normal subgroup, closed prime ideals inC
*(G) are always maximal which implies of course that PrimG isT
1. 相似文献
13.
Zusammenfassung Es wird gezeigt, dass eine isotrope Beziehung zwischen zwei symmetrischen Tensoren zweiten Ranges auf die Form gebracht werden kann, wobei sowie dieA
n,B
n,C
n ähnliche Potenzreihen in den Hauptinvarianten vonx
s
r
sind. Die Konstantenk müssen durch geeignete Versuche bestimmt werden, die über den Zusammenhang zwischen den physikalischen Grössenx
s
r
undy
s
r
Auskunft geben. Die können aber auch Konstanten sein. Dies trifft beispielsweise zu, wennx
s
r
undy
s
r
verschiedene Masse der Deformation sind. In diesem Falle kann man zum Beispiel das logarithmische Hencky-Mass durch das Almansi-Mass ausdrücken. Tut man dies, dann ergeben sich aus einer quasilinearen Spannungs-Fluss-Beziehung gewisse Effekte zweiter Ordnung in zähen Flüssigkeiten, auch dann, wenn das Medium unelastisch und die Zähigkeit gering ist. Damit liesse sich ein Zentripetalpump-Effekt in Luft, der neulich beobachtet worden ist, theoretisch erklären.
de|The symbols used are A indicatingAlmansi - A n,B n,C n coefficients - C indicatingCauchy - e strain - G indicatingGreen - g rs metric tensor - H indicatingHencky - i, j, k principal directions - K n constant coefficient - l length - l 0 initial length - l 1 final length - p s r stress tensor - S amount of shear, also indicatingSwainger - V volume - v velocity - x s r ,y s r symmetrical tensors of rank two - coefficient - l elongation - Kronecker's delta - coefficient of viscosity - c coefficient of cross viscosity - Lamé's constant - shear modulus - I, II, III principal invariants The research reported in this document has been sponsored in part by the Air Research and Development Command, United States Air Force, under Contract AF 61 (514)-871, through the European Office, ARDC. 相似文献
de|The symbols used are A indicatingAlmansi - A n,B n,C n coefficients - C indicatingCauchy - e strain - G indicatingGreen - g rs metric tensor - H indicatingHencky - i, j, k principal directions - K n constant coefficient - l length - l 0 initial length - l 1 final length - p s r stress tensor - S amount of shear, also indicatingSwainger - V volume - v velocity - x s r ,y s r symmetrical tensors of rank two - coefficient - l elongation - Kronecker's delta - coefficient of viscosity - c coefficient of cross viscosity - Lamé's constant - shear modulus - I, II, III principal invariants The research reported in this document has been sponsored in part by the Air Research and Development Command, United States Air Force, under Contract AF 61 (514)-871, through the European Office, ARDC. 相似文献
14.
a∈ C
1([0,1]) vanishing only at 0, 1 and b∈ C ([0,1]), we study existence, qualitative properties, asymptotic behaviour and approximation of the solutions of the degenerate
evolution problem u
t
= (au
z
)
z
- bu in ]0,1[x]0, + ∞[, with u(x,0) = u
0
(x) and boundary conditions a(x)u
x
(x,t) → 0 as x → 0,1, t > 0. 相似文献
15.
Elmar Schrohe 《Annals of Global Analysis and Geometry》1992,10(3):237-254
The pseudodifferential operators with symbols in the Grushin classes \~S
inf0
sup,
, 0 < 1, of slowly varying symbols are shown to form spectrally invariant unital Frécher-*-algebras (*-algebras) in L(L
2(R
n
)) and in L(H
st
) for weighted Sobolev spaces H
inf
supst
defined via a weight d function . In all cases, the Fredholm property of an operator can be characterized by uniform ellipticity of the symbol. This gives a converse to theorems of Grushin and Kumano-Ta-Taniguchi. Both, the spectrum and the Fredholm spectrum of an operator turn out to be independent of the choices of s, t and .The characterization of the Fredholm property by uniform ellipticity leads to an index theorem for the Fredholm operators in these classes, extending results of Fedosov and Hörmander. 相似文献
16.
A class of quasilinear stochastic partial differential equations of McKean-Vlasov type with mass conservation 总被引:2,自引:0,他引:2
Peter Kotelenez 《Probability Theory and Related Fields》1995,102(2):159-188
Summary A system ofN particles inR
d
with mean field interaction and diffusion is considered. Assuming adiabatic elimination of the momenta the positions satisfy a stochastic ordinary differential equation driven by Brownian sheets (microscopic equation), where all coefficients depend on the position of the particles and on the empirical mass distribution process. This empirical mass distribution process satisfies a quasilinear stochastic partial differential equation (SPDE). This SPDE (mezoscopic equation) is solved for general measure valued initial conditions by extending the empirical mass distribution process from point measure valued initial conditions with total mass conservation. Starting with measures with densities inL
2(R
d
,dr), wheredr is the Lebesgue measure, the solution will have densities inL
2(R
d
,dr) and strong uniqueness (in the Itô sense) is obtained. Finally, it is indicated how to obtain (macroscopic) partial differential equations as limits of the so constructed SPDE's.This research was supported by NSF grant DMS92-11438 and ONR grant N00014-91J-1386 相似文献
17.
Prof.Dr. Wolfgang M. Schmidt 《Monatshefte für Mathematik》1982,93(1):63-74
Hua andChen gave estimates of sums
wheree(z)=e
2iz
and
is a polynomial of the typef(x)/q wheref(x)=a
k
x
k
+...+a
1
x with integer coefficients having gcd (q, a
k
,...,a
1)=1 But no good estimates hold for these sums whenq is small in comparison tok. We therefore consider here a related but different class of polynomials. Special emphasis is given to the cubic case.In subsequent papers of this series we shall deal with cubic exponential sums in many variables and withp-adic and rational zeros of systems of cubic forms.Partially supported by NSF contract NSF-MCS-8015356. 相似文献
18.
Giovanni Sansone 《Annali di Matematica Pura ed Applicata》1974,98(1):167-181
Summary Si determinano tre classi di quartiche u2=ax4+1, a e b interi, b2−4a≠□ per le quali l'appartenenza di un punto razionale (x0,y0),x0≠0 porta l'esistenza nella stessa quartica di infiniti punti razionali.
Si dimostra pure che l'equazione 4x2+x2y2+4y4=□ non ammette soluzioni intere con |xy| > 1.
A BeniaminoSegre nel suo 70mo compleanno.
Entrata in Redazione il 26 febbraio 1973. 相似文献
19.
Ettore Santi 《Annali dell'Universita di Ferrara》1969,14(1):77-96
Riassunto In questa nota si considerano gli spazi funzionali
con norma mista, studiati daA. Benedek eR. Panzone, e vengono date delle condizioni sufficienti perchè una funzione misurabile sia un moltiplicatore dell’integrale di Fourier
da
a
. Tali condizioni sono l’estensione di quelle trovate daP. I. Lizorkin nel caso degli spazi di LebesgueL
p
(R
n
).
Lavoro esequito nell’ambito dell’attività dei gruppi di ricerca matematici del C.N.R. 相似文献
Résumé Dans cette note on considère les espaces fonctionnels avec norme mixte, étudiés parA. Benedek etR. Panzone, et l’on obtient quelques conditions suffisantes afin que une fonction mesurable soit un multiplicateur de l’intégral de Fourier. Ces conditions sont la généralisation de ceux découvertes parP. I. Lizorkin dans le cas des espaces de LebesgueL p (R n ).
Lavoro esequito nell’ambito dell’attività dei gruppi di ricerca matematici del C.N.R. 相似文献
20.
Maria Tallini Scafati 《Annali di Matematica Pura ed Applicata》1962,60(1):203-233
Riassunto Si definisce e si studia una nozione di distanza nello spazio proiettivo q aternionaleT
n
Q
, la quale si riduce nell'infinitesimo alla meirica riemanniana del modello metrico reale diT
n
Q
assegnato daMartinelli, e subordina le nozioni di distanza diCayley-Klein e diFubini-Study negli spazi proiettivi reale e complessoT
n
R
,T
n
C
subordinati aT
n
Q
.
A M. Enrico Bompiani nel suo giubileo scientifico
Lavoro eseguito nell'ambito del Gruppo di ricerca n. 37 del C. N. R. 相似文献