Hermite Calculus

We develop a new method of umbral nature to treat blocks of Her mite and of Hermite like poly- nomials as independent algebraic quantities. The Calculus we propose allows the formulation of a number of ”practical rules” allowing significant simplific ations in computational problem

New and interesting records of Brazilian bryophytes

This paper presents data on morphology, ecology and distribution of 16 species of bryophytes collected in Pernambuco, Brazil, that are interesting floristic records. Notothylasorbicularis (Schwein.) Sull. is new to Brazil, 11 species are new to the Northeast region of Brazil and 4 species are new to Pernambuco.Dados morfológicos, ecológicos e de distribuição geográfica são apresentados para 16 espécies de briófitas coletadas no Estado de Pernambuco, Brasil. Notothylas orbicularis (Schwein.) Sull. é registrada pela primeira vez para o Brasil, 11 espécies são novas para a região Nordeste e 4 para o Estado de Pernambuco

Ergodic transition in a simple model of the continuous double auction

We study a phenomenological model for the continuous double auction, whose aggregate order process is equivalent to two independent M/M/1 queues. The continuous double auction defines a continuous-time random walk for trade prices. The conditions for ergodicity of the auction are derived and, as a consequence, three possible regimes in the behavior of prices and logarithmic returns are observed. In the ergodic regime, prices are unstable and one can observe a heteroskedastic behavior in the logarithmic returns. On the contrary, non-ergodicity triggers stability of prices, even if two different regimes can be seen

Integrals of Special Functions and Umbral Methods

We derive integrals of combination of Gauss and Bessel functions, by the use of umbral techniques. We show that the method allows the possibility of pursuing new and apparently fruitful avenues in the theory of special functions, displaying interesting links with the theory and the formalism of integral transforms

Integrals of Special Functions and Umbral Methods

AbstractWe derive integrals of combination of Gauss and Bessel functions, by the use of umbral techniques. We show that the method allows the possibility of pursuing new and apparently fruitful avenues in the theory of special functions, displaying interesting links with the theory and the formalism of integral transforms