5,687 research outputs found
On localizations of quasi-simple groups with given countable center
A group homomorphism is a localization of if for every
homomorphism there exists a unique endomorphism
, such that (maps are acting on the
right). G\"{o}bel and Trlifaj asked in \cite[Problem 30.4(4), p. 831]{GT12}
which abelian groups are centers of localizations of simple groups. Approaching
this question we show that every countable abelian group is indeed the center
of some localization of a quasi-simple group, i.e. a central extension of a
simple group. The proof uses Obraztsov and Ol'shanskii's construction of
infinite simple groups with a special subgroup lattice and also extensions of
results on localizations of finite simple groups by the second author and
Scherer, Th\'{e}venaz and Viruel.Comment: 21 page
Generators and closed classes of groups
We show that in the category of groups, every singly-generated class which is
closed under isomorphisms, direct limits and extensions is also
singly-generated under isomorphisms and direct limits, and in particular is
co-reflective. We also establish several new relations between singly-generated
closed classes.Comment: 22 page
Distortion of boundary sets under inner functions. II
33 pages, no figures.-- MSC2000 codes: 32A30, 30C85, 30D50.MR#: MR1379286 (97b:30035)Zbl#: Zbl 0847.32005We present a study of the metric transformation properties of inner functions of several complex variables. Along the way we obtain fractional dimensional ergodic properties of classical inner functions.Publicad
Demand shocks and trade balance dynamics
This paper studies the current account dynamics in the G-7 countries plus Spain. We estimate a SVAR model which allows us to identify three different shocks: supply shocks, real demand shocks and nominal shocks. We use a different identification procedure from previous work based on a microfounded stochastic open-economy model in which the real exchange rate is a determinant of the Phillips curve. Estimates from a structural VAR show that real demand shocks explain most of the variability of current account imbalances, whereas, contrary to previous findings, nominal shocks play no role. The results we obtain are consistent with the predictions of a widely set of open-economy models and illustrate that demand policies are the main responsible of trade imbalances.Current account, SVAR
Productivity growth and technological change in Europe and the U.S.
This paper presents an evaluation on the technological sources of labor productivity growth across European countries and the US economy for the period 1980-2004. Assets of capital are divided into those related to the information and communication technologies (ICT), and non-ICT assets. Technological progress is divided into neutral change and investment specific change. Previous exercises have aimed at ICT as a serious contributor to the upsurge of US productivity from 1995 on. Contribution to productivity growth from each type of technological progress for the US and EU-15 countries is computed using two different approaches: a growth accounting and a general equilibrium. The US and Denmark are the countries with the larger contribution from ICT-technological progress. Overall, we find that Europe is well behind the US in terms of the effects of ICT technological change.Productivity growth, Investment-specific technological change, Neutral technological change
Non-simple localizations of finite simple groups
Often a localization functor (in the category of groups) sends a finite
simple group to another finite simple group. We study when such a localization
also induces a localization between the automorphism groups and between the
universal central extensions. As a consequence we exhibit many examples of
localizations of finite simple groups which are not simple.Comment: 10 page
Los prisioneros de guerra españoles en la URSS: el relato de embajadores en el infierno y la narración histórica
I Congreso Internacional de Historia y Cine: 5, 6, 7 y 8 de Septiembre de 2007
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