Majorana and the investigation of infrared spectra of ammonia

An account is given on the first studies on the physics of ammonia, focusing on the infrared spectra of that molecule. Relevant contributions from several authors, in the years until 1932, are pointed out, discussing also an unknown study by E.Majorana on this topic.Comment: 13 page

Some considerations on pitch

Pitch is an audible quality of sound which can be explained not only in terms of strong correlation with sound waves’ properties, but also by a neat correlation to the properties of the sounding object. This seems to be in favour of the theory of sound labelled “distal view”, according to which sound is the vibration of the sounding object

On multivariable cumulant polynomial sequences with applications

A new family of polynomials, called cumulant polynomial sequence, and its extensions to the multivariate case is introduced relied on a purely symbolic combinatorial method. The coefficients of these polynomials are cumulants, but depending on what is plugged in the indeterminates, either sequences of moments either sequences of cumulants can be recovered. The main tool is a formal generalization of random sums, also with a multivariate random index and not necessarily integer-valued. Applications are given within parameter estimations, L\'evy processes and random matrices and, more generally, problems involving multivariate functions. The connection between exponential models and multivariable Sheffer polynomial sequences offers a different viewpoint in characterizing these models. Some open problems end the paper.Comment: 17 pages, In pres

Polynomial traces and elementary symmetric functions in the latent roots of a non-central Wishart matrix

Hypergeometric functions and zonal polynomials are the tools usually addressed in the literature to deal with the expected value of the elementary symmetric functions in non-central Wishart latent roots. The method here proposed recovers the expected value of these symmetric functions by using the umbral operator applied to the trace of suitable polynomial matrices and their cumulants. The employment of a suitable linear operator in place of hypergeometric functions and zonal polynomials was conjectured by de Waal in 1972. Here we show how the umbral operator accomplishes this task and consequently represents an alternative tool to deal with these symmetric functions. When special formal variables are plugged in the variables, the evaluation through the umbral operator deletes all the monomials in the latent roots except those contributing in the elementary symmetric functions. Cumulants further simplify the computations taking advantage of the convolution structure of the polynomial trace. Open problems are addressed at the end of the paper

On a representation of time space-harmonic polynomials via symbolic L\'evy processes

In this paper, we review the theory of time space-harmonic polynomials developed by using a symbolic device known in the literature as the classical umbral calculus. The advantage of this symbolic tool is twofold. First a moment representation is allowed for a wide class of polynomial stochastic involving the L\'evy processes in respect to which they are martingales. This representation includes some well-known examples such as Hermite polynomials in connection with Brownian motion. As a consequence, characterizations of many other families of polynomials having the time space-harmonic property can be recovered via the symbolic moment representation. New relations with Kailath-Segall polynomials are stated. Secondly the generalization to the multivariable framework is straightforward. Connections with cumulants and Bell polynomials are highlighted both in the univariate case and in the multivariate one. Open problems are addressed at the end of the paper

The Method of Contrast and the Perception of Causality in Audition

The method of contrast is used within philosophy of perception in order to demonstrate that a specific property could be part of our perception. The method is based on two passages. I argue that the method succeeds in its task only if the intuition of the difference, which constitutes the core of the first passage, has two specific traits. The second passage of the method consists in the evaluation of the available explanations of this difference. Among the three outlined options, I will demonstrate that only in the third option – as we shall see, the case of the scenario that remains the same but is perceived in two different ways by the same perceiver – the intuition purports a difference that posses the necessary characteristics, namely being immediately evident and extremely complex and multifaceted, which determine its tensive nature. The application within auditory perception of this third option will generate two cases, a diachronic one and a synchronic one, which clearly show that we can auditorily perceive causality as a link between two sonorous episodes. The causal explanation is the only possible explanation among the many evaluated within the second passage of the method of contrast

Role of T-odd functions in high energy hadronic collisions

I propose a simple model for predicting the enegy behavior of T-odd, chiral odd function $h_1^{\perp}$. Furthermore I illustrate a method for extracting $h_1^{\perp}$ and the transversity function from Drell-Yan. The method may be applied also to other reactions.Comment: Talk given at Brookhaven, Spin-200