4,570 research outputs found
Central Banking and the Choice of Currency Regime in Accession Countries
The subject matter of this paper is the design of appropriate Central Banking arrangements and exchange rate regimes for those former centrally planned Central and East European countries that are candidates for full membership in the European Union. We give an overview of the existing arrangements and point out to which extent monetary arrangements are restricted by conditions for entry both into the European Union and eventually into the European Monetary Union. Furthermore we investigate to which degree countries are fulfilling the accession criteria and compare their performance with the performance of earlier EU joiners like the countries of the Iberian Peninsula, Ireland and Greece.
Torsional Newton-Cartan Geometry and Lifshitz Holography
We obtain the Lifshitz UV completion in a specific model for z=2 Lifshitz
geometries. We use a vielbein formalism which enables identification of all the
sources as leading components of well-chosen bulk fields. We show that the
geometry induced from the bulk onto the boundary is a novel extension of
Newton-Cartan geometry with a specific torsion tensor. We explicitly compute
all the vevs including the boundary stress-energy tensor and their Ward
identities. After using local symmetries/Ward identities the system exhibits
6+6 sources and vevs. The FG expansion exhibits, however, an additional free
function which is related to an irrelevant operator whose source has been
turned off. We show that this is related to a second UV completion.Comment: v2: 5 pages, matches version published in PR
Role of multiorbital effects in the magnetic phase diagram of iron-pnictides
We elucidate the pivotal role of the bandstructure's orbital content in
deciding the type of commensurate magnetic order stabilized within the
itinerant scenario of iron-pnictides. Recent experimental findings in the
tetragonal magnetic phase attest to the existence of the so-called charge and
spin ordered density wave over the spin-vortex crystal phase, the latter of
which tends to be favored in simplified band models of itinerant magnetism.
Here we show that employing a multiorbital itinerant Landau approach based on
realistic bandstructures can account for the experimentally observed magnetic
phase, and thus shed light on the importance of the orbital content in deciding
the magnetic order. In addition, we remark that the presence of a hole pocket
centered at the Brillouin zone's -point favors a magnetic stripe
rather than a tetragonal magnetic phase. For inferring the symmetry properties
of the different magnetic phases, we formulate our theory in terms of magnetic
order parameters transforming according to irreducible representations of the
ensuing D point group. The latter method not only provides
transparent understanding of the symmetry breaking schemes but also reveals
that the leading instabilities always belong to the subset
of irreducible representations, independent of their C or C nature.Comment: 11 pages, 6 figure
Direct observation of interface and nanoscale compositional modulation in ternary III-As heterostructure nanowires
Straight, axial InAs nanowire with multiple segments of GaInAs were grown.
High resolution X-ray energy-dispersive spectroscopy (EDS) mapping reveal the
distribution of group III atoms at the axial interfaces and at the sidewalls.
Significant Ga enrichment, accompanied by a structural change is observed at
the GaInAs/InAs interfaces and a higher Ga concentration for the early grown
GaInAs segments. The elemental map and EDS line profile infer Ga enrichment at
the facet junctions between the sidewalls. The relative chemical potentials of
ternary alloys and the thermodynamic driving force for liquid to solid
transition explains the growth mechanisms behind the enrichment.Comment: 12 Pages, 4 figure
Accurate DNA assembly and genome engineering with optimized uracil excision cloning
Simple
and reliable DNA editing by uracil excision (a.k.a. USER
cloning) has been described by several research groups, but the optimal
design of cohesive DNA ends for multigene assembly remains elusive.
Here, we use two model constructs based on expression of <i>gfp</i> and a four-gene pathway that produces β-carotene to optimize
assembly junctions and the uracil excision protocol. By combining
uracil excision cloning with a genomic integration technology, we
demonstrate that up to six DNA fragments can be assembled in a one-tube
reaction for direct genome integration with high accuracy, greatly
facilitating the advanced engineering of robust cell factories
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