Instability and Trade in Currency Areas

In a currency area, when a country faces a positive shock inflation goes up, real interest rate decreases and competitiveness deteriorates. We show that the stability of equilibrium depends on the rationality of expectations and budget balance of the public sector.Publicad

Instability and trade in currency areas

We present a model of a currency area in which labor markets of country members are isolated but there is trade among these countries. When a country experiences a negative (resp. positive) shock, inflation goes down (up). This causes two effects. On the one hand the real interest rate of this country increases (decreases). On the other hand the goods produced in this country become more (less) competitive. We show that the stability of the system depends on several factors, including a large competitive effect, how inflation expectations are formed and fiscal policy. In general, stability requires a trade-off between the rationality of expectations and budget balance

Helico-conical optical beams self-heal

An optical beam is said to be self-healing when, distorted by an obstacle, the beam corrects itself upon propagation. In this letter, we show through experiments supported by numerical simulations, that Helico-conical optical beams (HCOBs) self-heal. We observe the strong resilience of these beams with different types of obstructions, and relate this to the characteristics of their transverse energy flow.Comment: 4 pages, 5 figure

Field squeeze operators in optical cavities with atomic ensembles

We propose a method of generating unitarily single and two-mode field squeezing in an optical cavity with an atomic cloud. Through a suitable laser system, we are able to engineer a squeeze field operator decoupled from the atomic degrees of freedom, yielding a large squeeze parameter that is scaled up by the number of atoms, and realizing degenerate and non-degenerate parametric amplification. By means of the input-output theory we show that ideal squeezed states and perfect squeezing could be approached at the output. The scheme is robust to decoherence processes.Comment: Four pages and one figure. Accepted in Physical Review Letter

Presentación de modelos de propagación de fisuras por acumulación de daño por fatiga

Se presenta un estudio de diferentes modelos de propagación de fisuras por fatiga que utilizan el concepto de daño . En particular se presentan y desarrollan tres modelos específicos. El modelo de Antolovich, el modelo de Duggan y el modelo de acumulación de daño plástico de Font Filax. Se hace hincapié en la fundamentación física de éstos, y en los parámetros que los gobiernan, así como en su rango de aplicabilidad