Lichnerowicz-type equations on complete manifolds

Under appropriate spectral assumptions we prove two existence results for positive solutions of Lichnerowicz-type equations on complete manifolds. We also give a priori bounds and a comparison result that immediately yields uniqueness for certain classes of solutions. No curvature assumptions are involved in our analysis.Comment: 33 pages, submitte

Lichnerowicz-type equations with sign-changing nonlinearities on complete manifolds with boundary

We prove an existence theorem for positive solutions to Lichnerowicz-type equations on complete manifolds with boundary and nonlinear Neumann conditions. This kind of nonlinear problems arise quite naturally in the study of solutions for the Einstein-scalar field equations of General Relativity in the framework of the so called Conformal Method

The Euro Changeover and Price Adjustments in Italy

By estimating a staggered price model over the period 1980q1-2010q2, this paper documents that, after the euro changeover, Italian retailers have increased the number of price adjustments, which has translated into a higher inflation rate, with a detrimental effect on the competitiveness of the Italian economy.Euro changeover, staggered price adjustments, inflation

The Euro Changeover and Price Adjustments in Italy

By estimating a staggered price model over the period 1980q1-2010q2, this paper documents that, after the euro changeover, Italian retailers have increased the number of price adjustments, which has translated into a higher inflation rate, with a detrimental effect on the competitiveness of the Italian economyEuro changeover, staggered price adjustments, inflation

Whitney stratifications are conically smooth

In their paper "Local structures on stratified spaces", Ayala, Francis and Tanaka introduced the notion of conically smooth structure on stratified spaces. This is a very well behaved analogous of a differential structure in the context of manifold stratified topological spaces, satisfying good properties such as the existence of resolutions of singularities and handlebody decompositions. In this paper we prove that any Whitney stratified space admits a conically smooth structure, as conjectured by Ayala, Francis and Tanaka themselves, thus establishing a connection between this new theory and the classical examples of stratified spaces from differential topology.Comment: 15 page

A portable laser system for high precision atom interferometry experiments

We present a modular rack-mounted laser system for the cooling and manipulation of neutral rubidium atoms which has been developed for a portable gravimeter based on atom interferometry that will be capable of performing high precision gravity measurements directly at sites of geophysical interest. This laser system is constructed in a compact and mobile design so that it can be transported to different locations, yet it still offers improvements over many conventional laboratory-based laser systems. Our system is contained in a standard 19" rack and emits light at five different frequencies simultaneously on up to 12 fibre ports at a total output power of 800 mW. These frequencies can be changed and switched between ports in less than a microsecond. The setup includes two phase-locked diode lasers with a phase noise spectral density of less than 1 \mu rad/sqrt(Hz) in the frequency range in which our gravimeter is most sensitive to noise. We characterize this laser system and evaluate the performance limits it imposes on an interferometer.Comment: 8 pages, 11 figures; The final publication is available at http://www.springerlink.co

Coherent control of quantum transport: modulation-enhanced phase detection and band spectroscopy

Amplitude modulation of a tilted optical lattice can be used to steer the quantum transport of matter wave packets in a very flexible way. This allows the experimental study of the phase sensitivity in a multimode interferometer based on delocalization-enhanced Bloch oscillations and to probe the band structure modified by a constant force.Comment: 8 pages, 3 figures, Submitted to EPJ Special Topics for the special issue on "Novel Quantum Phases and Mesoscopic Physics in Quantum Gases