Self-similar solutions for a superdiffusive heat equation with gradient nonlinearity

This paper is devoted to global well-posedness, self-similarity and symmetries of solutions for a superdiffusive heat equation with superlinear and gradient nonlinear terms with initial data in new homogeneous Besov-Morrey type spaces. Unlike the heat equation, we need to develop an appropriate decomposition of the two-parametric Mittag-Leffler function in order to obtain Mikhlin-type estimates get our well-posedness theorem. To the best of our knowledge, the present work is the first one concerned with a well-posedness theory for a time-fractional partial differential equations of order $\alpha\in(1,2)$ with non null initial velocity

Testing the Markov property with ultra-high frequency financial data

This paper develops a framework to nonparametrically test whether discretevalued irregularly-spaced financial transactions data follow a Markov process. For that purpose, we consider a specific optional sampling in which a continuous-time Markov process is observed only when it crosses some discrete level. This framework is convenient for it accommodates not only the irregular spacing of transactions data, but also price discreteness. Under such an observation rule, the current price duration is independent of previous price durations given the current price realization. A simple nonparametric test then follows by examining whether this conditional independence property holds. Finally, we investigate whether or not bid-ask spreads follow Markov processes using transactions data from the New York Stock Exchange. The motivation lies on the fact that asymmetric information models of market microstructures predict that the Markov property does not hold for the bid-ask spread. The results are mixed in the sense that the Markov assumption is rejected for three out of the five stocks we have analyzed.Bid-ask spread, nonparametric testing, price durations, Markov property, ultra-high frequency data

The insurance industry in Brazil: a long-term view

This paper surveys the formation and development of insurance business in Brazil. It describes its very first steps, from the colonial times and imperial era to recent events. Particular attention is given to regulatory changes, showing how they evolved in response to macroeconomic shocks that affected the Brazilian economy during this period.Insurance, Brazil, Regulation. JEL Code: G22, G38, L50, N46.

Critical dialogues: slow readings of English literary texts

The reader will find gathered together in this volume a selection of articles and essays that have been separately published over the past three decades as a result of my teaching practice and research activity. In chronological terms, they span a period from 1985 until May 2008. These texts were chosen because they are considered to be representative of the type of work I usually do in my classes, undoubtedly as a result of my own academic background, based on a deliberate and specific form of approach to literary texts, my own choice of English authors and, lastly, my most recent interest in inter-art studies.Fundação para a Ciência e a Tecnologi

The insurance industry in Brazil: a long-term view

This paper surveys the formation and development of insurance business in Brazil. It describes its origins, from the colonial times and imperial era to recent events. Particular attention is given to regulatory changes, showing how they evolved in response to macroeconomic shocks that affected the Brazilian economy during this period.Insurance, Brazil, Regulation

Cooperative response and clustering : Consequences of membrane-mediated interactions among mechanosensitive channels

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