Scielo RSS <![CDATA[Cubo (Temuco)]]> http://www.scielo.cl/rss.php?pid=0719-064620130003&lang=es vol. 15 num. 3 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[An Elementary Study of a Class of Dynamic Systems with Single Time Delay]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300001&lng=es&nrm=iso&tlng=es A complete eigenvalue analysis is given for a certain class of dynamic systems with a single delay. The stability region is determined and it is demonstrated that there is only one stability switch. Special cases from economics, biology and engineering illustrate the importance of such models.<hr/>Un análisis completo de los autovalores se entrega para una clase de sistemas dinámicos con retardo simple. La región de estabilidad se determina y se demuestra que existe solamente un switch de estabilidad. Casos especiales para Economía, Biología e Ingeniería ilustran la importancia de los modelos mencionados. <![CDATA[Approximating a solution of an equilibrium problem by Viscosity iteration involving a nonexpansive semigroup]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300002&lng=es&nrm=iso&tlng=es In this paper we have defined a new iteration in order to solve an equilibrium problem in Hilbert spaces. The iteration we have introduced is a viscosity type iteration and involves a semigroup of nonexpansive operators. We have established that depending on some control conditions, our iteration strongly converges to a solution of the equilibrium problem.<hr/>En este artículo hemos definido una iteración nueva para resolver un problema de equilibrio en espacios de Hilbert. La iteración que introducimos es de tipo viscoso e involucra un semigrupo de operadores no expansivos. Hemos establecido que dependiendo de las condiciones de control, nuestra iteración converge fuertemente a una solución de un problema de equilibrio. <![CDATA[Composition operators in hyperbolic general Besov-type spaces]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300003&lng=es&nrm=iso&tlng=es In this paper we introduce natural metrics in the hyperbolic α-Bloch and hyperbolic general Besov-type classes F*(p, q, s). These classes are shown to be complete metric spaces with respect to the corresponding metrics. Moreover, compact composition operators <img src="http:/fbpe/img/cubo/v15n3/art03-fig5.jpg" name="_x0000_i1038" width=26 height=24 border=0 id="_x0000_i1038">acting from the hyperbolic α-Bloch class to the class F*(p, q, s) are characterized by conditions depending on an analytic self-map <img src="http:/fbpe/img/cubo/v15n3/art03-fig6.jpg" name="_x0000_i1037" width=18 height=26 border=0 id="_x0000_i1037">: D<img src="http:/fbpe/img/cubo/v15n3/art03-fig1.jpg" name="_x0000_i1036" width=25 height=16 border=0 id="_x0000_i1036"> D.<hr/>En este artí­culo introducimos una métrica natural en las clases hiperbólicas α-Bloch y tipo Besov generales. Estas clases se muestra que son espacios métricos completos respecto de las métricas correspondientes. Además se caracterizan los operadores de composición compactos <img src="http:/fbpe/img/cubo/v15n3/art03-fig5.jpg" name="_x0000_i1035" width=26 height=24 border=0 id="_x0000_i1035">que actúan desde las clases hiperbólicas α-Bloch en la clase F*(p, q, s) por condiciones que dependen de la autoaplicación analí­tica <img src="http:/fbpe/img/cubo/v15n3/art03-fig6.jpg" name="_x0000_i1034" width=18 height=26 border=0 id="_x0000_i1034">: D<img src="http:/fbpe/img/cubo/v15n3/art03-fig1.jpg" name="_x0000_i1033" width=25 height=16 border=0 id="_x0000_i1033"> D. <![CDATA[Coincidence and common fixed point theorems in Non-Archimedean Menger PM-spaces]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300004&lng=es&nrm=iso&tlng=es The object of this work is to point out a fallacy in the proof of Theorem 1 contained in the recent paper of Khan et al. [Jordan J. Math. Stat. (JJMS) 5(2) (2012), 137-150] proved in Non-Archimedean Menger PM-space by using the notions of sub-compatibility and sub-sequential continuity. We show that the results of Khan et al. [Jordan J. Math. Stat. (JJMS) 5(2) (2012), 137-150] an be recovered in two ways. Further, we establish some illustrative examples to show the validity of the main results. Our results improve a multitude of relevant fixed point theorems of the existing literature.<hr/>El objetivo de este trabajo es señalar una falacia en la demostración del Teorema 1 contenido en un articulo reciente de Khan et al. [Jordan J. Math. Stat. (JJMS) 5(2) (2012), 137-150] probado en un espacio-PM No-Arquimedeano Menger usando nociones de continuidad subcompatible y sub secuencial. Mostramos que el resultado de Khan et al. [Jordan J. Math. Stat. (JJMS) 5(2) (2012), 137-150] puede recuperarse de dos maneras. Además, establecemos algunos ejemplos ilustrativos que muestran la validez de los resultados principales. Nuestro resultado mejora una gran cantidad de teoremas de punto fijo importantes existentes en la literatura. <![CDATA[On centralizers of standard operator algebras with involution]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300005&lng=es&nrm=iso&tlng=es The purpose of this paper is to prove the following result. Let <img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1106" width=18 height=25 border=0 id="_x0000_i1106">be a complex Hilbert space, let <img src="http:/fbpe/img/cubo/v15n3/art05-fig2.jpg" name="_x0000_i1105" width=19 height=24 border=0 id="_x0000_i1105">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1104" width=18 height=25 border=0 id="_x0000_i1104">) be the algebra of all bounded linear operators on <img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1103" width=18 height=25 border=0 id="_x0000_i1103">and let <img src="http:/fbpe/img/cubo/v15n3/art05-fig3.jpg" name="_x0000_i1102" width=22 height=24 border=0 id="_x0000_i1102">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1101" width=18 height=25 border=0 id="_x0000_i1101">) <img src="http:/fbpe/img/cubo/v15n3/art05-fig6.jpg" name="_x0000_i1100" width=17 height=18 border=0 id="_x0000_i1100"><img src="http:/fbpe/img/cubo/v15n3/art05-fig2.jpg" name="_x0000_i1099" width=19 height=24 border=0 id="_x0000_i1099">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1098" width=18 height=25 border=0 id="_x0000_i1098">) be a standard operator algebra, which is closed under the adjoint operation. Let <img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1097" width=15 height=21 border=0 id="_x0000_i1097">: <img src="http:/fbpe/img/cubo/v15n3/art05-fig3.jpg" name="_x0000_i1096" width=22 height=24 border=0 id="_x0000_i1096">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1095" width=18 height=25 border=0 id="_x0000_i1095">)<img src="http:/fbpe/img/cubo/v15n3/art03-fig1.jpg" name="_x0000_i1094" width=25 height=16 border=0 id="_x0000_i1094"> <img src="http:/fbpe/img/cubo/v15n3/art05-fig2.jpg" name="_x0000_i1093" width=19 height=24 border=0 id="_x0000_i1093">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1092" width=18 height=25 border=0 id="_x0000_i1092">) be a linear mapping satisfying the relation 2<img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1091" width=15 height=21 border=0 id="_x0000_i1091">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1090" width=18 height=21 border=0 id="_x0000_i1090"><img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1089" width=18 height=21 border=0 id="_x0000_i1089">*<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1088" width=18 height=21 border=0 id="_x0000_i1088">) = <img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1087" width=15 height=21 border=0 id="_x0000_i1087">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1086" width=18 height=21 border=0 id="_x0000_i1086">)<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1085" width=18 height=21 border=0 id="_x0000_i1085">*<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1084" width=18 height=21 border=0 id="_x0000_i1084"> + <img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1083" width=18 height=21 border=0 id="_x0000_i1083"><img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1082" width=18 height=21 border=0 id="_x0000_i1082">*<img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1081" width=15 height=21 border=0 id="_x0000_i1081">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1080" width=18 height=21 border=0 id="_x0000_i1080">) for all <img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1079" width=18 height=21 border=0 id="_x0000_i1079"><img src="http:/fbpe/img/cubo/v15n3/art05-fig7.jpg" name="_x0000_i1078" width=17 height=17 border=0 id="_x0000_i1078"><img src="http:/fbpe/img/cubo/v15n3/art05-fig3.jpg" name="_x0000_i1077" width=22 height=24 border=0 id="_x0000_i1077">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1076" width=18 height=25 border=0 id="_x0000_i1076">). In this case <img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1075" width=15 height=21 border=0 id="_x0000_i1075">is of the form <img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1074" width=15 height=21 border=0 id="_x0000_i1074">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1073" width=18 height=21 border=0 id="_x0000_i1073">) = λ<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1072" width=18 height=21 border=0 id="_x0000_i1072"> for all <img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1071" width=18 height=21 border=0 id="_x0000_i1071"><img src="http:/fbpe/img/cubo/v15n3/art05-fig7.jpg" name="_x0000_i1070" width=17 height=17 border=0 id="_x0000_i1070"><img src="http:/fbpe/img/cubo/v15n3/art05-fig3.jpg" name="_x0000_i1069" width=22 height=24 border=0 id="_x0000_i1069">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1068" width=18 height=25 border=0 id="_x0000_i1068">), where λ is some fixed complex number.<hr/>El propósito de este artí­culo es probar el siguiente resultado. Sea <img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1067" width=18 height=25 border=0 id="_x0000_i1067">un espacio de Hilbert complejo, sea <img src="http:/fbpe/img/cubo/v15n3/art05-fig2.jpg" name="_x0000_i1066" width=19 height=24 border=0 id="_x0000_i1066">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1065" width=18 height=25 border=0 id="_x0000_i1065">) el álgebra de todos los operadores lineales acotados sobre <img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1064" width=18 height=25 border=0 id="_x0000_i1064">y sea <img src="http:/fbpe/img/cubo/v15n3/art05-fig3.jpg" name="_x0000_i1063" width=22 height=24 border=0 id="_x0000_i1063">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1062" width=18 height=25 border=0 id="_x0000_i1062">) <img src="http:/fbpe/img/cubo/v15n3/art05-fig6.jpg" name="_x0000_i1061" width=17 height=18 border=0 id="_x0000_i1061"><img src="http:/fbpe/img/cubo/v15n3/art05-fig2.jpg" name="_x0000_i1060" width=19 height=24 border=0 id="_x0000_i1060">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1059" width=18 height=25 border=0 id="_x0000_i1059">) la álgebra de operadores clásica, la cual es cerrada bajo la operación adjunto. Sea <img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1058" width=15 height=21 border=0 id="_x0000_i1058">: <img src="http:/fbpe/img/cubo/v15n3/art05-fig3.jpg" name="_x0000_i1057" width=22 height=24 border=0 id="_x0000_i1057">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1056" width=18 height=25 border=0 id="_x0000_i1056">)<img src="http:/fbpe/img/cubo/v15n3/art03-fig1.jpg" name="_x0000_i1055" width=25 height=16 border=0 id="_x0000_i1055"><img src="http:/fbpe/img/cubo/v15n3/art05-fig2.jpg" name="_x0000_i1054" width=19 height=24 border=0 id="_x0000_i1054">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1053" width=18 height=25 border=0 id="_x0000_i1053">) una aplicación lineal satisfaciendo la relación 2<img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1052" width=15 height=21 border=0 id="_x0000_i1052">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1051" width=18 height=21 border=0 id="_x0000_i1051"><img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1050" width=18 height=21 border=0 id="_x0000_i1050">*<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1049" width=18 height=21 border=0 id="_x0000_i1049">) = <img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1048" width=15 height=21 border=0 id="_x0000_i1048">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1047" width=18 height=21 border=0 id="_x0000_i1047">)<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1046" width=18 height=21 border=0 id="_x0000_i1046">*<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1045" width=18 height=21 border=0 id="_x0000_i1045"> + <img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1044" width=18 height=21 border=0 id="_x0000_i1044"><img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1043" width=18 height=21 border=0 id="_x0000_i1043">*<img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1042" width=15 height=21 border=0 id="_x0000_i1042">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1041" width=18 height=21 border=0 id="_x0000_i1041">) para todo <img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1040" width=18 height=21 border=0 id="_x0000_i1040"><img src="http:/fbpe/img/cubo/v15n3/art05-fig7.jpg" name="_x0000_i1039" width=17 height=17 border=0 id="_x0000_i1039"><img src="http:/fbpe/img/cubo/v15n3/art05-fig3.jpg" name="_x0000_i1038" width=22 height=24 border=0 id="_x0000_i1038">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1037" width=18 height=25 border=0 id="_x0000_i1037">). En este caso, <img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1036" width=15 height=21 border=0 id="_x0000_i1036">es de la forma <img src="http:/fbpe/img/cubo/v15n3/art05-fig4.jpg" name="_x0000_i1035" width=15 height=21 border=0 id="_x0000_i1035">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1034" width=18 height=21 border=0 id="_x0000_i1034">) = λ<img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1033" width=18 height=21 border=0 id="_x0000_i1033"> para todo <img src="http:/fbpe/img/cubo/v15n3/art05-fig5.jpg" name="_x0000_i1032" width=18 height=21 border=0 id="_x0000_i1032"><img src="http:/fbpe/img/cubo/v15n3/art05-fig7.jpg" name="_x0000_i1031" width=17 height=17 border=0 id="_x0000_i1031"><img src="http:/fbpe/img/cubo/v15n3/art05-fig3.jpg" name="_x0000_i1030" width=22 height=24 border=0 id="_x0000_i1030">(<img src="http:/fbpe/img/cubo/v15n3/art05-fig1.jpg" name="_x0000_i1029" width=18 height=25 border=0 id="_x0000_i1029">), donde λ es un número complejo fijo. <![CDATA[Generalization of New Continuous Functions in Topological Spaces]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300006&lng=es&nrm=iso&tlng=es In this paper, ωα-closed sets and ωα-open sets are used to dene and investigate the new classes of functions namely somewhat ωα-continuous functions and totally ωα-continuous functions.<hr/>En este artículo conjuntos cerrados-ωα y abiertos-ωα se usan para definir e investigar las clases de nuevas funciones continuas ωα y totalmente ontinuas ωα. <![CDATA[On quasi-conformally flat and quasi-conformally semisymmetric generalized Sasakian-space-forms]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300007&lng=es&nrm=iso&tlng=es The object of the present paper is to study quasi-conformally flat and quasi-conformally semisymmetric generalized Sasakian-space-forms.<hr/>El objeto del artí­culo actual es estudiar formas de espacio Sasakian cuasi-conformacionales planas y cuasi-conformacionales generalizadas semisimétricas. <![CDATA[Convergence theorems for generalized asymptotically quasi-nonexpansive mappings in cone metric spaces]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300008&lng=es&nrm=iso&tlng=es The purpose of this paper is to study an Ishikawa type iteration process with errors to approximate the common fixed point of two generalized asymptotically quasinonexpansive mappings in the framework of cone metric spaces. Our results extend and generalize many known results from the existing literature.<hr/>El propósito de este artículo es estudiar el proceso de iteración del tipo Ishikawa con errores para aproximar el puto fijo común de dos aplicaciones cuasi-expansivas asintéticamente generalizadas en el marco de espacios métricos cónicos. Nuestro resultado extiende y generaliza muchos resultados de la literatura existente. <![CDATA[Approximate solution of fractional integro-differential equation by Taylor expansion and Legendre wavelets methods]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300009&lng=es&nrm=iso&tlng=es This paper, deals with the approximate solution of fractional integro-differential equations of the type <img src="http:/fbpe/img/cubo/v15n3/art09-fig1.jpg" name="_x0000_i1032" width=422 height=63 border=0 id="_x0000_i1032">t <img src="http:/fbpe/img/cubo/v15n3/art05-fig7.jpg" name="_x0000_i1031" width=17 height=17 border=0 id="_x0000_i1031">I = [0,1] by Taylor expansion and Legendre wavelet methods.In addition, illustrative example are presented to demonstrate the efficiency and accuracy of this methods.<hr/>Este artí­culo considera la solución aproximada de ecuaciones integro-diferenciales fraccionales del tipo <img src="http:/fbpe/img/cubo/v15n3/art09-fig1.jpg" name="_x0000_i1030" width=422 height=63 border=0 id="_x0000_i1030">t <img src="http:/fbpe/img/cubo/v15n3/art05-fig7.jpg" name="_x0000_i1029" width=17 height=17 border=0 id="_x0000_i1029">I = [0,1] por expansiones de Taylor y métodos de Ondeletas de Legendre. Además, un ejemplo ilustrativo se presenta para mostrar la eficiencia y precisión de este método. <![CDATA[Euler's constant, new classes of sequences and estimates]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300010&lng=es&nrm=iso&tlng=es We give two classes of sequences with the argument of the logarithmic term modified and also with some additional terms besides those in the denition sequence, and that converge quickly to <img src="http:/fbpe/img/cubo/v15n3/art10-fig1.jpg" name="_x0000_i1043" width=380 height=40 border=0 id="_x0000_i1043">, where a <img src="http:/fbpe/img/cubo/v15n3/art05-fig7.jpg" name="_x0000_i1042" width=17 height=17 border=0 id="_x0000_i1042">(0, + <img src="http:/fbpe/img/cubo/v15n3/art10-fig7.jpg" name="_x0000_i1041" width=18 height=13 border=0 id="_x0000_i1041">). We present the pattern in forming these sequences, expressing the coefficients that appear with the Bernoulli numbers. Also, we obtain estimates containing best constants for <img src="http:/fbpe/img/cubo/v15n3/art10-fig2.jpg" name="_x0000_i1040" width=507 height=41 border=0 id="_x0000_i1040">and <img src="http:/fbpe/img/cubo/v15n3/art10-fig3.jpg" name="_x0000_i1039" width=38 height=28 border=0 id="_x0000_i1039"><img src="http:/fbpe/img/cubo/v15n3/art10-fig4.jpg" name="_x0000_i1038" width=600 height=38 border=0 id="_x0000_i1038">, where <img src="http:/fbpe/img/cubo/v15n3/art10-fig5.jpg" name="_x0000_i1037" width=19 height=23 border=0 id="_x0000_i1037" > or = <img src="http:/fbpe/img/cubo/v15n3/art10-fig5.jpg" name="_x0000_i1036" width=19 height=23 border=0 id="_x0000_i1036">(1) is the Euler's onstant.<hr/>Mostramos dos clases de secuencias con el argumento del término logarítmico modificado y también con algunos términos adicionales además de los definidos en la secuencia y que convergen rápidamente a<img src="http:/fbpe/img/cubo/v15n3/art10-fig1.jpg" name="_x0000_i1035" width=380 height=40 border=0 id="_x0000_i1035"> , donde a <img src="http:/fbpe/img/cubo/v15n3/art05-fig7.jpg" name="_x0000_i1034" width=17 height=17 border=0 id="_x0000_i1034">(0, + <img src="http:/fbpe/img/cubo/v15n3/art10-fig7.jpg" name="_x0000_i1033" width=18 height=13 border=0 id="_x0000_i1033">). Presentamos el patrón que forma las secuencias expresando los coefientes que aparecen en los números de Bernoulli. Además, obtenemos estimaciones que contienen las mejores constantes para <img src="http:/fbpe/img/cubo/v15n3/art10-fig2.jpg" name="_x0000_i1032" width=507 height=41 border=0 id="_x0000_i1032">y <img src="http:/fbpe/img/cubo/v15n3/art10-fig6.jpg" name="_x0000_i1031" width=600 height=33 border=0 id="_x0000_i1031">, donde <img src="http:/fbpe/img/cubo/v15n3/art10-fig5.jpg" name="_x0000_i1030" width=19 height=23 border=0 id="_x0000_i1030" > o = <img src="http:/fbpe/img/cubo/v15n3/art10-fig5.jpg" name="_x0000_i1029" width=19 height=23 border=0 id="_x0000_i1029">(1) es la constante de Euler. <![CDATA[K-theory for the group C*-algebras of nilpotent discrete groups]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0719-06462013000300011&lng=es&nrm=iso&tlng=es We study the K-theory groups for the group C*-algebras of nilpotent discrete groups, mainly, without torsion. We determine the K-theory class generators for the K-theory groups by using generalized Bott projections.<hr/>Estudiamos los grupos de la K-teorí­a para el grupo de álgebras C* de grupos discretos nilpotentes principalmente sin torsión. Determinamos los generadores de la lase de K-teorí­a para los grupos de la K-teorí­a usando proyecciones generalizadas de Bott.