15,030 research outputs found
Dynamics, Welfare and Migration in Open Economies
In this work we analyze the importance of dynamics in the determination of the distribution of gains from free trade and migration. Given a transition dynamic, free trade might worsen a country relatively to autarchy. Moreover, some individuals might lose welfare during the transition dynamics. In both case, individuals find incentives to migrating, given the lost in the welfare relatively to the autarchy; given the lost in welfare relatively to another country; or, given the intertemporal lost in welfare. Then, inequalities in the distribution of the benefits from free trade matters. Finally, we find out that population size and specialization in production matters in the determination of the distribution of gains from free trade and migration.Migration; free trade; welfare; transition dynamics
Self-consistent 2D models of fast rotating early-type star
This work aims at presenting the first two-dimensional models of an isolated
rapidly rotating star that include the derivation of the differential rotation
and meridional circulation in a self-consistent way.We use spectral methods in
multidomains, together with a Newton algorithm to determine the steady state
solutions including differential rotation and meridional circulation for an
isolated non-magnetic, rapidly rotating early-type star. In particular we
devise an asymptotic method for small Ekman numbers (small viscosities) that
removes the Ekman boundary layer and lifts the degeneracy of the inviscid
baroclinic solutions.For the first time, realistic two-dimensional models of
fast-rotating stars are computed with the actual baroclinic flows that predict
the differential rotation and the meridional circulation for intermediate-mass
and massive stars. These models nicely compare with available data of some
nearby fast-rotating early-type stars like Ras Alhague ( Oph), Regulus
( Leo), and Vega ( Lyr). It is shown that baroclinicity drives
a differential rotation with a slow pole, a fast equator, a fast core, and a
slow envelope. The differential rotation is found to increase with mass, with
evolution (here measured by the hydrogen mass fraction in the core), and with
metallicity. The core-envelope interface is found to be a place of strong shear
where mixing will be efficient.Two-dimensional models offer a new view of
fast-rotating stars, especially of their differential rotation, which turns out
to be strong at the core-envelope interface. They also offer more accurate
models for interpreting the interferometric and spectroscopic data of
early-type stars.Comment: 16 pages, 17 figures, to appear in Astronomy and Astrophysic
What is the upper limit on the lightest supersymmetric Higgs mass?
In this talk the question of what is the upper bound on the lightest
supersymmetric Higgs mass, m_h is addressed. This question is relevant since
experimental lower bounds on m_h might implement, in the near future, exclusion
of supersymmetry. By imposing (perturbative) unification of the gauge couplings
at some high scale \simgt 10^{17} GeV, we have found that for a top-quark mass
M_t=175 GeV, and depending on the supersymmetric parameters, this bound can be
as high as 205 GeV.Comment: 7 pages, 4 figures, Work presented at PASCOS-98, March 22-29 199
First Glimpses at Higgs' face
The 8 TeV LHC Higgs search data just released indicates the existence of a
scalar resonance with mass ~ 125 GeV. We examine the implications of the data
reported by ATLAS, CMS and the Tevatron collaborations on understanding the
properties of this scalar by performing joint fits on its couplings to other
Standard Model particles. We discuss and characterize to what degree this
resonance has the properties of the Standard Model (SM) Higgs, and consider
what implications can be extracted for New Physics in a (mostly)
model-independent fashion. We find that, if the Higgs couplings to fermions and
weak vector bosons are allowed to differ from their standard values, the SM is
~ 2 sigma from the best fit point to current data. Fitting to a possible
invisible decay branching ratio, we find BR_{inv} = 0.05\pm 0.32\ (95% C.L.) We
also discuss and develop some ways of using the data in order to bound or rule
out models which modify significantly the properties of this scalar resonance
and apply these techniques to the global current data set.Comment: 26 pages, 7 figures, v2 post ICHEP data updat
Composite Higgs under LHC Experimental Scrutiny
The LHC has been built to understand the dynamics at the origin of the
breaking of the electroweak symmetry. Weakly coupled models with a fundamental
Higgs boson have focused most of the attention of the experimental searches. We
will discuss here how to reinterpret these searches in the context of strongly
coupled models where the Higgs boson emerges as a composite particle. In
particular, we use LHC data to constrain the compositeness scale. We also
briefly review the prospects to observe other bosonic and fermionic resonances
of the strong sector.Comment: 6 pages. Contribution to the proceedings of Hadron Collider Physics
Symposium 2011, Paris Nov. 14-1
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