12,848 research outputs found
Exceptional theories
We present a new construction of four dimensional theories,
given by M5 branes wrapping a in an M-theory U-fold background. The
resulting setup generalizes the one used in the usual class
construction of four dimensional theories by using an extra discrete symmetry
on the M5 worldvolume. Together with the M-theory U-fold description of
-type six-dimensional SCFTs, this allows to construct new, exceptional,
theories.Comment: v2: Minor modifications, version to appear in JHE
Noise and aggregation of information in large markets
We study a novel class of noisy rational expectations equilibria in markets with large number of agents. We show that, as long as noise increases with the number of agents in the economy, the limiting competitive equilibrium is well-defined and leads to non-trivial information acquisition, perfect information aggregation, and partially revealing prices, even if per capita noise tends to zero. We find that in such equilibrium risk sharing and price revelation play dierent roles than in the standard limiting economy in which per capita noise is not negligible. We apply our model to study information sales by a monopolist, information acquisition in multi-asset markets, and derivatives trading. The limiting equilibria are shown to be perfectly competitive, even when a strategic solution concept is used.Partially revealing equilibria, competitive equilibrium, rational expectations, information acquisition, markets for information, derivatives trading, multi-asset markets, share auctions
AGN spiral galaxies in groups: effects of bars
We explore properties of barred active spiral galaxies in groups selected
from the SDSS-DR7, with the aim of assessing the effects of bars on AGN and the
role of the high density environment. We identified barred active galaxies that
reside in groups from SDSS-DR7 group catalog. To provide a suitable
quantification of the effects of bars, a reliable control sample of unbarred
active galaxies in high density environments with similar redshift, magnitude,
morphology, and bulge size distributions was constructed. We found that the
fraction of barred AGN galaxies in groups (~ 38 %) is higher than those in the
total barred AGN sample ( ~ 28 %), indicating that AGN spiral galaxies in
groups are more likely to be barred than those in the field. We also found that
barred AGN galaxies are more concentrated towards the group centers than the
other unbarred AGN group members. In addition, barred AGN host galaxies show an
excess of population dominated by red colors suggesting that bars produce an
importanteffect on galaxy colors of AGN hosts. The host groups of the barred
AGN exhibit a larger fraction of red colors than the host groups of the
corresponding unbarred active galaxies. Color-magnitude relations of both host
groups of AGN differ significantly: the host group colors of barred active
galaxies display distributions spreading toward red populations, with respect
to the host groups of the unbarred AGN objects. Barred active galaxies show an
excess of nuclear activity compared to galaxies without bars. We found that
barred active galaxies located farther from the group-center have stronger
Lum[OIII]. Our findings suggest that the efficiency of bars to transport
material towards the more central regions of the AGN galaxies in high density
environments reveals an important dependence on the localization of objects
within the group and on the host group colors.Comment: 10 pages, 10 figures. Accepted for Astronomy & Astrophysic
Thermodynamic, economic and environmental assessment of energy systems including the use of gas from manure fermentation in the context of the Spanish potential
One of the prospective technologies that can be used for energy generation in distributed systems is based on biogas production, usually involving fermentation of various types of biomass and waste. This article aims to bring novelty on the analysis of this type of systems, joining together thermodynamic, economic and environmental aspects for a cross-cutting evaluation of the proposed solutions. The analysis is made for Spain, for which such a solution is very promising due to availability of the feedstock. A detailed simulation model of the proposed system in two different cases was built in Aspen Plus software and Visual Basic for Applications. Case 1 involves production of biogas in manure fermentation process, its upgrading (cleaning and removal of CO2 from the gas) and injection to the grid. Case 2 assumes combustion of the biogas in gas engine to produce electricity and heat that can be used locally and/or sold to the grid. Thermodynamic assessment of these two cases was made to determine the most important parameters and evaluation indices. The results served as input values for the economic analysis and environmental evaluation through Life Cycle Assessment of the energy systems. The results show that the analysed technologies have potential to produce high-value products based on low-quality biomass. Economic evaluation determined the break-even price of biomethane (Case 1) and electricity (Case 2), which for the nominal assumptions reach the values of 16.77 €/GJ and 28.92 €/GJ, respectively. In terms of environmental assessment the system with the use of biogas in gas engine presents around three times better environmental profile than Case 1 in the two categories evaluated, i.e., carbon and energy footprint.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie SkĹ‚odowska-Curie grant agreement No 799439. Dr. MartĂn-Gamboa states that thanks are due to FCT/MCTES for the financial support to CESAM (UID/AMB/50017/2019), through national funds
El carácter ganancial o privativo de la indemnización por despido: Criterios delimitadores
No siempre ha sido pacĂfica la consideraciĂłn como bien ganancial o privativo de las indemnizaciones por
despido percibidas por uno de los cĂłnyuges. A partir de 2007 en adelante la doctrina del Tribunal Supremo generaliza
una serie de criterios a tener en cuenta para determinar si dicha indemnizaciĂłn puede considerarse como bien
privativo o ganancial y cuyas directrices han tratado de seguir las Audiencias ProvincialesIt hasn’t always peaceful the considerations as community property or privative of the compensation for
dismissal received by one of spouses. From 2007 until now the doctrine of the Supreme Court generalizes a number
of criteria to consider in determining if such compensation can be considered as a privative good or community
property good and whose underlines have tried to follow the provincial courts
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