The jet-disc connection: evidence for a reinterpretation in radio loud and radio quiet active galactic nuclei

To constrain models of the jet-disc connection, we explore Eddington ratios reported in Foschini (2011) and interpret them in relation to the values in Sikora et al. across the active galactic nuclei population from radio loud quasars, their flat spectrum radio quasar subclass, the recently discovered gamma-ray loud narrow-line type 1 Seyfert galaxies, Fanaroff-Riley type I (FRI) radio galaxies and radio quiet quasars of the Palomar Green survey. While appeal to disc truncation in radiatively inefficient flow appears to explain the observed inverse relation between radio loudness and Eddington ratio in radio loud and radio quiet quasars, FR I objects, scale invariance and recent data on powerful jets in narrow-line Seyfert 1 galaxies offer compelling arguments in favour of a reinterpretaion of the jet-disc connection

On the methodologies for the assessment of the impact of parameters in acoustophoretic separation devices

In this communication I reconcile the kinematic method illustrated by some authors~\cite{yang2018,vitali2018} in studying the impact of system and suspension parameters on acoustophoretic separations with the statistical method formerly proposed by Garofalo~\cite{garofalo2014,garofalo2014_2} and lately extended to particle populations by the same author~\cite{garofalo2017,garofalo2018}. The connection between these two methods is established by (i)~reinterpreting the kinematic method in terms of tangent space dynamics, and (ii)~transforming the dynamics in the tangent space into the dynamics of the area elements. The dynamics of the area elements is equivalent to the dynamics of the covariance matrix derived by moment analysis and associated with the dispersion problem during microparticle acoustophoresis. The similarities and the differences between the kinematic based method and the stochastic method proposed by the present auuthor are illustrated and discussed in the light of the numerical results for a prototypical model of acoustophoretic separation. \keywords{Acoustof

Reading the Transformations of an Urban Edge: From Liberty Era Palermo to the City of Today

To honour the battle of 27 May 1860, in 1910 the Palermo City Government decided to realise a commemorative monument. A position at the centre of a large circular plaza was of have afforded the monument a greater solemnity. The commission for the Monument was awarded to Ernesto Basile. In 1927 the City Government decided to dedicate the monument to the Fallen and asked Basile to complete the monument adding an architectural backdrop. The first version of the new project was a fence that enveloped the entire square and the ring road, interrupted only by entrances near the streets flowing into the square, and dividing it into four sectors. The final design instead called for the realisation of a semi-circular exedra of columns interrupted at the centre by a large gate that allows access to the square and to the back of the monument. The successive development of the city engulfed the square in the midst of tall and anonymous buildings realised, beginning in the 1960s, without any order of relations, stripping the surrounding fabric of its identity. Through the survey of the today‘s configuration, the analysis of Basile‘s original drawings and the representation of the modifications made over time, this text proposes an original reading of the configuration of Piazza Vittorio Veneto and the Monument to the Fallen, in relation to important moments in its history, from its design to the present day. The three-dimensional models reproduce the monument and its surroundings at the time of its construction in 1910, based on the first version for its expansion (unbuilt), with the addition of the exedra from 1930 and in its current condition. The redesign and extrapolation of different views of the digital models also provided original images of use to new readings of the perception of this space

Gradient bounds and monotonicity of the energy for some nonlinear singular diffusion equations

We construct viscosity solutions to the nonlinear evolution equation \eqref{p} below which generalizes the motion of level sets by mean curvature (the latter corresponds to the case $p = 1$) using the regularization scheme as in \cite{ES1} and \cite{SZ}. The pointwise properties of such solutions, namely the comparison principles, convergence of solutions as $p\to 1$, large-time behavior and unweighted energy monotonicity are studied. We also prove a notable monotonicity formula for the weighted energy, thus generalizing Struwe's famous monotonicity formula for the heat equation ($p =2$)

Asset Price Dynamics in a Financial Market with Heterogeneous Trading Strategies and Time Delays

In this paper we present a continuous time dynamical model of heterogeneous agents interacting in a financial market where transactions are cleared by a market maker. The market is composed of fundamentalist, trend following and contrarian agents who process information from the market with different time delays. Each class of investor is characterized by path dependent risk aversion. We also allow for the possibility of evolutionary switching between trend following and contrarian strategies. We find that the system shows periodic, quasi-periodic and chaotic dynamics as well as synchronization between technical traders. Furthermore, the model is able to generate time series of returns that exhibit statistical properties similar to those of the S&P500 index, which is characterized by excess kurtosis, volatility clustering and long memoryComment: 14 pages, 5 figure