Revistas académicas de la Universidad Católica del Norte
Not a member yet
1687 research outputs found
Sort by
A commutator rigidity for function groups and Torelli’s theorem
No full textWe show that a non-elementary finitely generated torsion-free function group is uniquely determined by its commutator subgroup. In this way, we obtain a generalization of the results obtained in [2], [3] and [8]. This is well related to Torelli’s theorem for closed Riemann surfaces. For a general non-elementary torsion-free Kleinian group the above rigidity property still unknown
Orlicz - Pettis theorems for multiplier convergent operator valued series
No full textLet X, Y be locally convex spaces and L(X, Y ) the space of continuous linear operators from X into Y. We consider 2 types of multiplier convergent theorems for a series PTk in L(X, Y ). First, if ? is a scalar sequence space, we say that the series PTk is ? multiplier P convergent for a locally convex topology ? on L(X, Y ) if the series tkTk is ? convergent for every t = {tk} ? ?. We establish conditions on ? which guarantee that a ? multiplier convergent series in the weak or strong operator topology is ? multiplier convergent in the topology of uniform convergence on the bounded subsets of X. Second, we consider vector valued multipliers. If E is a sequence space of X valued sequences, the series PTk is E multiplier convergent in a locally convex topology ? on Y if the series PTkxk is ? convergent for every x = {xk} ? E. We consider a gliding hump property on E which guarantees that a series PTk which is E multiplier convergent for the weak topology of Y is E multiplier convergent for the strong topology of Y
Caracterisation des relations binaires finies d-demi-reconstructibles
No full textGiven a binary relation R of basis E, we define its dual R? by R? (x, y) = R(y, x). A relation R is self-dual if it is isomorphic to R? . A binary relation R0 is hemimorphic to R, if it is isomorphic to R or to R? . A binary relation R is d-half-reconstructible if it is determined by its restrictions of cardinality d, up to hemimorphism. In this paper we characterize the finite binary relations d-half-reconstructibile for every d ? {7, 8, 9, 10, 11}
On the invariance of subspaces in some baric algebras
No full textIn this article, we look for invariance in commutative baric algebras (A, ?) satisfying (x 2 ) 2 = ?(x)x 3 and in algebras satisfying (x 2 ) 2 = ?(x 3 )x, using subspaces of kernel of ? that can be obtained by polynomial expressions of subspaces Ue e Ve of Peirce decomposition A = Ke ? Ue ? Ve of A, where e is an idempotent element. Such subspaces are called p -subspaces. Basically, we prove that for these algebras, the p -subspaces have invariant dimension, besides that, we find out necessary and sufficient conditions for the invariance of the p-subspaces
Bounds for conformal automorphisms of riemann surfaces with condition (A)
No full textIn this note we consider a class of groups of conformal automorphisms of closed Riemann surfaces containing those which can be lifted to some Schottky uniformization. These groups are those which satisfy a necessary condition for the Schottky lifting property. We find that all these groups have upper bound 12(g ? 1), where g ? 2 is the genus of the surface. We also describe a sequence of infinite genera g1 < g2 < · · · for which these upper bound is attained. Also lower bounds are found, for instance, (i) 4(g+1) for even genus and 8(g?1) for odd genus. Also, for cyclic groups in such a family sharp upper bounds are given
L-fuzzy closure operator
No full textThe aim of this paper is to study L-fuzzy closure operator in Lfuzzy topological spaces. We introduce two kinds of L-fuzzy closure operators from different point view and prove that both L-TFCS–the category of topological L-fuzzy closure spaces–and L-PTFCS–the category of topological pointwise L-fuzzy closure spaces–are isomorphic to L-FCTOP
On operator ideals defined by a reflexive Orlicz sequence space
No full textClassical theory of tensornorms and operator ideals studies mainly those defined by means of sequence spaces ℓp. Considering Orlicz sequence spaces as natural generalization of ℓp spaces, in a previous paper [12] an Orlicz sequence space was used to define a tensornorm, and characterize minimal and maximal operator ideals associated, by using local techniques. Now, in this paper we give a new characterization of the maximal operator ideal to continue our analysis of some coincidences among such operator ideals. Finally we prove some new metric properties of tensornorm mentioned above
On normal numbers
No full textA real number α is said to be normal to base 10 if, for every natural number L, each finite sequence of L digits appears in the decimals of α with frequency 1/10L. Even intuitive results concerning normal numbers presents complicated formalizations and to decide whether a given number is normal or not is sometimes almost impossible. In this paper we prove that if η = 0; a1a2a3a4... is a normal number, then = 0, a1a1a2a1a2a3a1a2a3a4... is also normal. On the other hand, if η fails to be normal, there are some technical difficulties in order to decide whether is normal or not, and we also discuss the normality (or not) of when η fails to be normal
Asymptotic equilibrium for certain type of differential equations with maximum
No full textIn this work we obtain asymptotic representations for the solutions of certain type of differential equations with maximum. We deduce the asymptotic equilibrium for this class of differential equations
On fuzzy weakly semiopen functions
No full textIn this paper, we introduce and characterize fuzzy weakly semiopen functions between fuzzy topological spaces as natural dual to the fuzzy weakly semicontinuous functions and also study these functions in relation to some other types of already known functions.