2,448 research outputs found
NLO QCD corrections to the production of a weak boson pair associated by a hard jet
In this talk we discuss recent progress concerning precise predictions for
the LHC. We give a status report of an application of the GOLEM method to deal
with multi-leg one-loop amplitudes, namely the next-to-leading order QCD
corrections to the process pp to V V + jet, where V is a weak boson W,Z.Comment: Talk at 2008 Rencontres de Moriond, QCD session, La Thuile, March
2007. Four page
The Regulation of Residential Tenancy Markets in Post-War Western Europe: An Economic Analysis
This paper provides an economic analysis of the post-war regulation of European tenancy markets. Two representative types of market regulation are analyzed: the introduction of compulsory duration clauses in tenancy contracts (as a means of protecting the tenant against eviction); and rent control policies. First, the study describes and analyzes the recent history of such regulations in Spain, Italy, Finland and the UK, in order to draw some general conclusions about the evolution of European institutions in recent decades. Their effects are then explored by adapting a theoretical model of tenancy markets. The results show that both rent control and compulsory duration clauses potentially entail negative effects for European tenancy markets as they may drive some participants out of the market. These effects are consistent with the trends observed during the latter half of the 20th century in several European countries.Rent control, Tenancy contracts, Compulsory terms
NLO QCD corrections to ZZ+jet production at hadron colliders
A fully differential calculation of the next-to-leading order QCD corrections
to the production of Z-boson pairs in association with a hard jet at the
Tevatron and LHC is presented. This process is an important background for
Higgs particle and new physics searches at hadron colliders. We find sizable
corrections for cross sections and differential distributions, particularly at
the LHC. Residual scale uncertainties are typically at the 10% level and can be
further reduced by applying a veto against the emission of a second hard jet.
Our results confirm that NLO corrections do not simply rescale LO predictions.Comment: 15 pages, 4 figures, 4 tables; added 1 reference, version to appear
in Phys. Lett.
The effect of institutions on European housing markets : an economic analysis
Durante el siglo XX y en especial en su segunda mitad, el mercado de alquiler
ha ido perdiendo peso a favor de la vivienda en propiedad tanto en la economía
española como en la del resto de países europeos. El gráfico R.1 muestra esta tendencia
negativa en el peso del mercado del alquiler sobre el total de viviendas principales1 para
algunas economías europeas en los años más recientes.
En este contexto y si bien la reducción en el peso del mercado de alquiler (a
favor del mercado de vivienda en propiedad) es un hecho común a la práctica totalidad
de países, el caso español es especialmente extremo. El primer censo que recogió esta
información (1970) ya indicaba que la proporción de vivienda principal en propiedad
estaba en torno al 60% (tasa de propiedad del 63’4%). En el año 2008 era posible
encontrar provincias españolas en las que la tasa de vivienda principal en propiedad
superaba el 94% (Castellón, Soria o Lugo).
Desde un punto de vista puramente económico, una fortaleza excesiva de la
vivienda en propiedad genera algunas ineficiencias en el funcionamiento de la
economía. Entre otros factores este efecto se debe a que una reducida tasa de alquiler
puede acabar disminuyendo la movilidad de los trabajadores (Hardman e Ionnides, 1999, Barceló, 2006). De hecho se observa que las economías con una mayor tasa de
alquiler, como Francia o Alemania, también muestran una mayor movilidad
interregional (Maclennan et al. 1998, Barceló, 2006). Paralelamente, la literatura
económica relaciona una baja movilidad con un mayor desempleo (Layard et al. 1991).
Numerosos factores pueden haber afectado a los mercados inmobiliarios
impulsando al alza el mercado de la vivienda en propiedad. Entre ellos y sobre todo para
los últimos años cabe citar la reducción general de los tipos de interés (Blanco y Restoy,
2007) junto a la liberalización bancaria (Iacoviello y Minetti, 2003, Kumbhakar y
Lozano-Vivas, 2004) o los aumentos en la renta per capita.
Frente a estos factores, ampliamente estudiados en la literatura, otros factores
que se podrían englobar como “institucionales” pueden también haber influenciado las
tasas de alquiler y propiedad. Entre ellos, cabría citar la regulación de los mercados (las llamadas “instituciones formales”) y el funcionamiento del sistema judicial como medio de ejecución de los contratos y pactos realizados en esos mercados (las llamadas
“instituciones de ejecución”). En ambos casos se puede afirmar que no han sido
suficientemente estudiadas en cuanto a sus efectos en los mercados inmobiliarios. En
consecuencia, esta tesis doctoral se centra en el análisis de los efectos de la regulación de los mercados inmobiliarios, en especial las normativas vigentes en los mercados de
alquiler, que podrían haber introducido desincentivos relativamente importantes para los arrendadores de vivienda así como el efecto del buen o mal funcionamiento del sistema
judicial a la hora de hacer cumplir los pactos y contratos efectuados en esos mercado
Is judicial inefficiency increasing the house property market weight in Spain? : evidence at the local level
Compared with the rest of the European countries the weight of the house property market in Spain is very high, which is consistent with the weakness of the tenancy market. In this context, it has often been argued that an inefficient judicial system, implying a cumbersome procedure to evict a non-paying tenant or simply needing a long period to execute a decision, may be an important determinant of the tenancy market weakness, as it constrains the effective supply by reducing the profitability of landlords. This research has studied this effect econometrically using a panel data approach and exploiting the differences in the judicial efficiency that exists among the Spanish provinces. After controlling for several other factors, this study concludes that the degree of inefficiency of the judicial system has a positive, although minor, impact on the differences in the property share among provinces in Spai
The impact of the efficacy of justice on business investment in Spain
Artículo de revistaOne of the main determinants of the level of dynamism of business investment is the efficacy of the legal system, as an essential element of the institutional framework of an economy. This article sets out an empirical approach to the impact of the efficacy of justice on the investment decisions of a sample of Spanish firms. Drawing on the cross-provincial heterogeneity in the court congestion rate, and how it changes over time, this analysis suggests there is a positive and significant correlation between efficacy in the civil justice system and business investment in Spain
32 Bin Near-Infrared Time-Multiplexing Detector with Attojoule Single-Shot Energy Resolution
We present two implementations of photon counting time-multiplexing detectors
for near-infrared wavelengths, based on Peltier cooled InGaAs/InP avalanche
photo diodes (APDs). A first implementation is motivated by practical
considerations using only commercially available components. It features 16
bins, pulse repetition rates of up to 22 kHz and a large range of applicable
pulse widths of up to 100 ns. A second implementation is based on rapid gating
detectors, permitting deadtimes below 10 ns. This allows one to realize a high
dynamic-range 32 bin detector, able to process pulse repetition rates of up to
6 MHz for pulse width of up to 200 ps. Analysis of the detector response at
16.5% detection efficiency, reveals a single-shot energy resolution on the
attojoule level.Comment: 7 pages, 7 figure
Comparison of Bond Character in Hydrocarbons and Fullerenes
We present a comparison of the bond polarizabilities for carbon-carbon bonds
in hydrocarbons and fullerenes, using two different models for the fullerene
Raman spectrum and the results of Raman measurements on ethane and ethylene. We
find that the polarizabilities for single bonds in fullerenes and hydrocarbons
compare well, while the double bonds in fullerenes have greater polarizability
than in ethylene.Comment: 7 pages, no figures, uses RevTeX. (To appear in Phys. Rev. B.
Centralized and Distributed Power Allocation for Max-Min Fairness in Cell-Free Massive MIMO
Cell-free Massive MIMO systems consist of a large number of geographically distributed access points (APs) that serve users by coherent joint transmission. Downlink power allocation is important in these systems, to determine which APs should transmit to which users and with what power. If the system is implemented correctly, it can deliver a more uniform user performance than conventional cellular networks. To this end, previous works have shown how to perform system-wide max-min fairness power allocation when using maximum ratio precoding. In this paper, we first generalize this method to arbitrary precoding, and then train a neural network to perform approximately the same power allocation but with reduced computational complexity. Finally, we train one neural network per AP to mimic system-wide max-min fairness power allocation, but using only local information. By learning the structure of the local propagation environment, this method outperforms the state-of-the-art distributed power allocation method from the Cell-free Massive MIMO literature
Litigation in Spain 2001-2010 : exploring the market for legal services
Existe evidencia empírica de que se da una asociación positiva entre el número de abogados por habitante y el número de litigios entre países. Por ejemplo, España cuenta con más litigios y más abogados por habitante que la mayoría de los países de la OCDE. ¿Cómo interpretar esta asociación? En este trabajo se analiza la variación de ambas variables en las provincias españolas durante el período 2001-2010 y, por medio de un enfoque econométrico de variables instrumentales, se ilustran algunas de las causas de la asociación estadística entre ellas y se comentan ciertas implicaciones de los resultadosThere is empirical evidence of a cross-country positive association between the number of lawyers per capita and the extent of litigation. For instance, Spain has more litigation and more lawyers per capita than most OECD countries. How should this association be interpreted? In this paper we analyse the variation in both variables across Spanish provinces during the period 2001-2010, by means of an instrumental variable approach, to shed some light on the sources of the statistical association between them. Finally, implications of the results are discusse
- …