Structural stability for the splash singularities of the water waves problem

In this paper we show a structural stability result for water waves. The main motivation for this result is that we would like to exhibit a water wave whose interface starts as a graph and ends in a splash. Numerical simulations lead to an approximate solution with the desired behaviour. The stability result will conclude that near the approximate solution to water waves there is an exact solution.Comment: 50 pages, 2 figure

Modelos espaciales de riesgo de depredación de animales domésticos por grandes carnívoros en Brasil

El conflicto humano-fauna silvestre provocado por la depredación de los animales domésticos tiene un impacto significativo en las poblaciones de carnívoros. En Brasil, el puma y el jaguar son las especies más afectadas, por lo que es imperativo identificar los patrones espaciales del riesgo de depredación a nivel del bioma, a través del análisis cuantitativo y también con un enfoque predictivo. Se utilizó una base de datos de registros de depredación, variables antrópicas, topográficas y de vegetación para generar Modelos Espaciales de Riesgo de depredación utilizando Modelos de Nicho Ecológico. Los modelos de ensamble se generaron en cinco biomas para ambos depredadores. Las variables asociadas al riesgo de depredación fueron diferentes entre especies y biomas. El riesgo de depredación del puma es influenciado principalmente por variables antrópicas, mientras que para el jaguar se da por una combinación de variables de tipo antrópico y tipos de vegetación. La generación de modelos espaciales permite predecir e identificar áreas con alto riesgo de depredación, así como las variables que las caracterizan. El análisis de la información a escala de biomas, junto con la disponibilidad de datos confiables y la implementación de métodos estadísticamente robustos, proporciona una perspectiva más específica de los patrones espaciales de depredación. Tales resultados pueden ser utilizados en la aplicación de estrategias para mitigar la depredación de animales domésticos.Consejo Nacional de Ciencia y Tecnología (CONACYT) beca nacional con número de registro 585494 y la beca mixta para estancias en el extranjer

On the compensation for illiquidity in sovereign credit markets

This article analyzes the role of liquidity in the sovereign credit default swap (CDS) market. We employ a continuous-time specification to incorporate illiquidity as an additional pricing factor of default swap contracts for the most developed economies. The illiquidity discount process is identified as compensation to investors for the risk of unwinding their positions when trading in the less liquid part of the curve, and the information about illiquidity is directly extracted from the term structure of sovereign CDS spreads. Our empirical findings reveal that a positive time-varying illiquidity premium is embedded in sovereign default swaps. These risk premia exhibit substantial comovement across countries. Only unidirectional causality from default to liquidity is detected for the overall market.We are exceptionally grateful to Jonatan Groba for his valuable comments and suggestions. J.A. Lafuente acknowledges financial support from the Spanish Ministry of Economy and Competitiveness through grant ECO2012-31941, the Generalitat Valenciana through grant PrometeoII/2013/015 and the University Jaume I through grant P1.1A2012-09. P. Serrano acknowl- edges financial support from the Spanish Ministry of Economy and Competitiveness through grant ECO2012-34268 and from Junta de Andalucía project P12-SEJ-1733

Voluntary pre-trade anonymity and market liquidity

This paper analyses the effects on liquidity of voluntary pre-trade anonymity in the trading process. We confirm previous studies showing that market liquidity improves immediately after anonymous trading. Using the daily percentage of effective volume traded anonymously, we show that the anonymity–liquidity relationship presents a non-linear U-shape. We focus on the voluntary concealment of broker identification introduced by the Spanish Stock Exchange in October 2015. We conclude that, in our sample, anonymity increases stock liquidity but at a decreasing rate; when a considerable part of the effective volume is traded anonymously, additional percentages of anonymous trading deteriorates stock liquidity.This work was supported by the Comunidad de Madrid [S2015/HUM-3353 (EARLYFIN-CM)]; Ministerio de Ciencia y Tecnología [ECO2015-69205-P]; Ministerio de Economía y Competitividad [ECO2014-51914-P]; Fondos FEDER [UNC315-EE-3636]; Basque Government [IT1336-19]