The well-known Thullen-Remmert-Stein’s theorem ([9], [7]) asserts that, for a domain D in CN and an n-dimensional irreducible analytic set S in D, a purely n-dimensional analytic set A in D — S has an essential singularity at any point in 5 if A has at least one essential singularity in S. In [1], E. Bishop generalized this to the case that A has the boundary of capacity zero in his sense. Afterwards, in [8], W. Rothstein obtained more precise informations on the essential singularities of A under the assumption dim A = 1. The main purpose in this paper is to generalize these Rothstein’s results to the case of arbitrary dimensional analytic sets.

Linear differential equations have been studied more throughly than any other class. They posses a group of characteristic properties: the invariance of linearity by linear transformations, the linearly dependence of solutions on their initial values, e.t.c. The next simple type of differential equations is quadratic type

A linear Lie algebra is called toroidal if it is abelian and consists of semi-simple transformations. The maximum, t(L), of the dimensions of the toroidal subalgebras of the derivation algebra, Δ(L), is an invariant of L. This paper is mainly concerned with the relation between the magnitude of t(L) for nilpotent L and the structures of L and Δ(L).

1. Let D be a positive square-free integer. Throughout this note we shall use the following notations;

d = d(D): the discriminant of ,

t0, u0: the least positive solution of Pell’s equation t2 — du2 = 4,

Let G be a finite group and let p be a fixed prime number. If D is any p-subgroup of G, then the problem whether there exists a p-block with D as its defect group is reduced to whether NG(D)/D possesses a p-block of defect 0. Some necessary or sufficient conditions for a finite group to possess a p-block of defect 0 have been known (Brauer-Fowler [1], Green [3], Ito [4] [5]). In this paper we shall show that the existences of such blocks depend on the multiplicative structures of the p-elements of G. Namely, let p be a prime divisor of p in an algebraic number field which is a splitting one for G, o the ring of p-integers and k = o/p, the residue class field.

Soient X un groupe abélien localement compact et non-compact, et dx sa mesure de Haar. Rappelons qu’un noyau de convolution N sur X est une mesure de Radon positive dans X. Il est symétrique s’il est symétrique par rapport à l’origine. Notons MK la totalité de fonctions mesurables, bornées dans X, à valeurs réelles et à support compact. On dit que N est de type positif si, quelle que soit f une fonction de et la signe * est la convolution sur X.

Le noyau de Riesz-Frostman dans l’espace euclidien à d(≥3) dimensions est à la puissance fractionnaire du noyau de Newton. On trouve la conformité dans la théorie des espaces de Dirichlet; on construit un noyau à la puissance fractionnaire d’un noyau associé à l’espace de Dirichlet spécial, qui détermine à nouveau un espace de Dirichlet spécial [2]. En notant que le noyau de Dirichlet est positif et symétrique, et satisfait au principe complet du maximum, on s’interroge: est-il possible de construire de bons noyaux à la puissance fractionnaire pour des noyaux de genre plus large?

Let S(n) be the matrix of a positive definite quadratic form and

Define

1.

Here the sum is over unimodular matrices which lie in a complete set of representatives for the equivalence relation with P unimodular and having block form

In this paper certain relations between non-compact transformation groups and compact transformation groups are studied. The notion of re-ducibility and separability of transformation groups is introduced, several necessary and sufficient conditions are established: (1) A separable transformation group to be locally weakly almost periodic, (2) A reducible and separable transformation group to be a minimal set and (3) A reducible and separable transformation group to be a fibre bundle. As applications we show, among other things, that (1) for certain reducible transformation groups its fundamental group is not trivial which is a generalization of a result in [4].

The purpose of this paper is to generalize the notion of the stable manifolds in Smale [5] and [6], in which the stable manifolds of flows or diifeomorphisms for a singular point or a closed orbit are defined in certain conditions. This generalization is concerned with Fenichel [1], He considers the stable manifolds of flows and diifeomorphisms for a torus. Here, we consider the case of a compact manifold. But our argument does not exactly imply Fenichel’s result.

Dans la théorie du potentiel par rapport à la noyau-fonction continue (au sens large), les théorèmes de Ninomiya et ceux de Kishi sont très originels (cf. [9] et [7]). Dans cet article, en généralisant la notion du noyau, on se propose de discuter quelques théorèmes analoques.

The study of regular points for the Dirichlet problem has a long history. The probabilistic approach to regular points is originated by Doob [2] and [3] for Brownian motion and the heat process. The extension to general Markov processes is discussed in Dynkin [4] and [5]. They also clarified the relation between the fine topology and regular points.

Regular points are by definition reflected in the behaviour of sample paths of Markov processes. Further the inclusion relation of collections of regular points for open sets determines the strength and the weakness of fine topologies between two processes. Hence it is meaningful to compare the collections of regular points for compact or open sets between two Markov processes apart from the Dirichlet problem.