843 research outputs found
Unemployment hysteresis, structural changes, non-linearities and fractional integration in European transition economies
In this paper we aim to analyse the dynamics of unemployment in a group of Central and Eastern European Countries (CEECs). The CEECs are of special importance for the future of the European Union, given that most of them have recently become member states, and labour flows have been seen to rise with their accession. By means of unit root tests incorporating structural changes and nonlinearities, as well as fractional integration, we find that the unemployment
rates for the CEECs are mean reverting processes, which is consistent with the NAIRU hypothesis, although shocks tend to be highly persistent
Semipurity of tempered Deligne cohomology
In this paper we define the formal and tempered Deligne cohomology groups,
that are obtained by applying the Deligne complex functor to the complexes of
formal differential forms and tempered currents respectively. We then prove the
existence of a duality between them, a vanishing theorem for the former and a
semipurity property for the latter. The motivation of these results comes from
the study of covariant arithmetic Chow groups. The semi-purity property of
tempered Deligne cohomology implies, in particular, that several definitions of
covariant arithmetic Chow groups agree for projective arithmetic varieties
A note on inflation and transplanckian physics
In this paper we consider the influence of transplanckian physics on the CMBR
anisotropies produced by inflation. We consider a simple toy model that allows
for analytic calculations and argue on general grounds, based on ambiguities in
the choice of vacuum, that effects are expected with a magnitude of the order
of , where is the Hubble constant during inflation and
the scale for new physics, e.g. the Planck scale.Comment: 12 pages. v2: typos corrected and references added. v3: final version
accepted for publication by PRD. Improved discussion of adiabatic vacuu
The sustainability of European external debt: What have we learned?
In this paper we aim to analyse the level of sustainability of external debt and, more importantly, how it has changed for a number of European economies. Given the severity of the crisis since 2008, we argue that the path of external debt burdens may have changed since the start of the crisis, given the concerns about debt accumulation in most countries. We follow the advice of Bohn (2007) and analyse the reaction of present debt accumulation to past debt stock, incorporating the possibility of endogenously determined structural breaks in this reaction function. We find that structural breaks happen in most cases after 2008, highlighting the importance of the policy measures taken by most governments
Chapter 19. The Blackspot seabream fishery in the Strait of Gibraltar: lessons and future perspectives of shared marine resource
The Blackspot seabream (Pagellus bogaraveo) is one of the most important commercially-exploited fish species for the Spanish and Moroccan fleets which operate in the Strait of Gibraltar. In recent years, landings of Blackspot seabream in the main ports have decreased significantly respect previous periods of maximum catches, which makes it necessary to properly assess the abundance before establishing a management plan to make the fishery sustainable over time. In this chapter, we describe three different approaches to assess the abundance of this species in the Strait of Gibraltar. The results of three approaches tested (LCA/VPA, Gadget model and SimFish model) point out that from the 2010 the stock is kept at very low levels that oscillate between 900 and 1600 t, which supposes that the total biomass is between a 16% and 29% of the potential biomass. Additionally, the reference point values estimated by LCA/VPA and Gadget (F0.1 = 0.12-0.17) imply a clear overexploitation of the resource what is reinforced by the SimFish model results indicating that at least the 64% of abundance variation is a consequence of the fishery component.En prens
Tachyon warm inflationary universe model in the weak dissipative regime
Warm inflationary universe model in a tachyon field theory is studied in the
weak dissipative regime. We develop our model for an exponential potential and
the dissipation parameter =constant. We describe scalar and
tensor perturbations for this scenario.Comment: 9 pages, accepted by European Physical Journal
The Blackspot seabream Spanish target fishery of the Strait of Gibraltar: updating the available information
This paper includes the available information of the Blackspot seabream
(Pagellus bogaraveo) Spanish target fishery in the Strait of Gibraltar updating
the documents presented in previous years with the information from 2019. So,
data about landings, fishing effort, CPUEs and landings length frequencies are
presented to its discussion within the 2020 WGDEEP
Hipodoncia: utilidad de hallazgos dentales en la determinación de patologías y parentesco en poblaciones antiguas. Estudio de dos casos en la necrópolis oriental de Carthago Spartaria
The use of forensic techniques when studying partial or badly-conserved human remains is very important when we want to determine age, sex, and race, as well as parental relation between two or more individuals. Of these techniques, some of the simplest but most reliable are those related to the dental studies of the retrieved remains. Finding dental anomalies may give useful information about diseases suffered by the individual (congenital or infecto-contagious) and possible family relation between several individuals. This study describes several cases of dental agenesia (absence of teeth caused by lack of formation of these teeth) found in populations living during the fi fth to seventh centuries (a.D.), retrieved in the oriental necropolis of Carthago Spartaria, in the neighborhood of the present University (Cartagena, Murcia).La utilización de técnicas forenses a la hora de estudiar restos humanos parciales o en mal estado de conservación son muy importantes cuando queremos determinar la edad, sexo y raza, así como el parentesco entre dos o más individuos. De estas técnicas, algunas de las más sencillas pero de resultados bastante fi ables son aquellas relacionadas con el estudio dental de los restos encontrados. El hallazgo de anomalías dentarias puede facilitar información acerca de enfermedades padecidas por el individuo (tanto infectocontagiosas como congénitas) y de posibles relaciones familiares entre varios individuos. El presente estudio describe varios casos de agenesias dentales (ausencia dental debida a la falta de formación de algún diente) encontradas en una población de los siglos V-VII d.C., recuperados en la necrópolis oriental de Carthago Spartaria, en la zona del actual Barrio Universitario. (Cartagena, Murcia
Modification to the power spectrum in the brane world inflation driven by the bulk inflaton
We compute the cosmological perturbations generated in the brane world
inflation driven by the bulk inflaton. Different from the model that the
inflation is a brane effect, we exhibit the modification of the power spectrum
of scalar perturbations due to the existence of the fifth dimension. With the
change of the initial vacuum, we investigate the dependence of the correction
of the power spectrum on the choice of the vacuum.Comment: replaced with the revised version, accepted for publication in PR
Force-free magnetosphere of an aligned rotator with differential rotation of open magnetic field lines
Here we briefly report on results of self-consistent numerical modeling of a
differentially rotating force-free magnetosphere of an aligned rotator. We show
that differential rotation of the open field line zone is significant for
adjusting of the global structure of the magnetosphere to the current density
flowing through the polar cap cascades. We argue that for most pulsars
stationary cascades in the polar cap can not support stationary force-free
configurations of the magnetosphere.Comment: 5 pages, 4 figures. Presented at the conference "Isolated Neutron
Stars: from the Interior to the Surface", London, April 24-28, 2006; to
appear in Astrophysics and Space Science. Significantly revised version, a
mistake found by ourselfs in the numerical code was corrected, all presented
results are obtained with the correct version of the cod
- …