990 research outputs found
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
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