Search results for "F36"
showing 8 items of 38 documents
From braid groups to mapping class groups
2005
This paper is a survey of some properties of the braid groups and related groups that lead to questions on mapping class groups.
On the classification of CAT(0) structures for the 4-string braid group
2005
This paper is concerned with the class of so-called CAT(0) groups, namely, those groups that admit a geometric (i.e., properly discontinuous, co-compact, and isometric) action on some CAT(0) space. More precisely, we are interested in knowing to what extent it is feasible to classify the geometric CAT(0) actions of a given group (up to, say, equivariant homothety of the space). A notable example of such a classification is the flat torus theorem, which implies that the minimal geometric CAT(0) actions of the free abelian group Z (n ≥ 1) are precisely the free actions by translations of Euclidean space E. Typically, however, a given group will have uncountably many nonequivalent actions, mak…
Integration of Capital Markets from Central and Eastern Europe: Implications for EU Investors
2014
Our paper investigates the extent of capital market co-movements between three emerging markets– Czech Republic, Hungary and Poland – and three developed markets from the European Union - Austria, France and Germany. We test whether an increase in correlations between the six markets took place in recent years, as revealing higher integration of capital markets in the region. We find a statistically significant positive trend in cross-market correlations between 1999 and 2008, before the emergence of the global financial crisis. Movements in national stock markets are not fully synchronized, but increases in market volatilities lead to increases in cross-country correlations. There is a lon…
Financial Fragmentation and Economic Growth in Europe
2015
Using industry data from Eurostat and applying the Rajan-Zingales methodology, we investigate the real growth effects of banking sector integration in the European Union. Our sample stretches from 2000 until 2012 and includes the phase of rapid financial integration before the global financial crisis as well as the following phase of financial fragmentation and bank deleveraging. We find evidence that banking sector integration had a more than four times stronger growth effect during the crisis than in normal times. Growth effects are also stronger in times of domestic bank deleveraging. We conclude that concerns of European policy makers about fragmentation in the European banking sector a…
Embeddings of graph braid and surface groups in right-angled Artin groups and braid groups
2003
We prove by explicit construction that graph braid groups and most surface groups can be embedded in a natural way in right-angled Artin groups, and we point out some consequences of these embedding results. We also show that every right-angled Artin group can be embedded in a pure surface braid group. On the other hand, by generalising to right-angled Artin groups a result of Lyndon for free groups, we show that the Euler characteristic -1 surface group (given by the relation x^2y^2=z^2) never embeds in a right-angled Artin group.
The Dynamics of Currency Substitution: Evidence from UK Foreign Currency Balances
2006
This study evaluates the magnitude of the permanent and the transitory components of currency substitution in the UK. The results indicate that the permanent component, the ratchet effect, accounted only for a small share while the aggregate temporary component, speculation, whose impact lasts about one month, was responsible for most of the dynamics of UK currency substitution. The findings thus lend support to the view that at worst currency substitution would only cause short-run problems for the UK economy.
The Euro and Monetary Policy Transparency
2002
This paper focuses on a possible explanation for the weakness of the euro, namely the lack of transparency of the European Central Bank's (ECB) monetary policy. In order to obtain a time-varying measure of monetary policy uncertainty in both the U.S. and Euroland, we estimate a Stochastic Volatility model using policy-adjusted short-term interest rates. We also analyze directly the impact of higher uncertainty on the euro-dollar exchange rate. The empirical findings are in line with those of other studies, and show that the U.S. Fed is more transparent than the ECB. This results in higher volatility of European interest rates, capital outflows, and a weaker euro vis-a-vis the U.S. dollar.
STATE AID POLICY BETWEEN COMPETITION AND ECONOMIC GROWTH: THE IMPACT OF STATE AID TO R&D ON GDP IN THE EU MEMBER STATES
2012
The paper focuses on the analysis of the relationship between state aid to R&D and economic growth, measured by GDP level, providing empirical evidence of a correlation between these variables. Using a methodology which combines the regression technique and Granger causality, we found that GDP represents a significant causal determinant of state aid, while the correlation the variables considered is positive and statistically significant, suggesting that, in spite of disparities between Member States, government support through state aid to R&D has evolved from maintaining undistorted competition to the possibility to act as an incentive for the economic growth in the EU.