85,426 research outputs found
Modified Special Relativity on a fluctuating spacetime
No full textIt was recently proposed that deformations of the relativistic symmetry, as those considered in deformed special relativity (DSR), can be seen as the outcome of a measurement theory in the presence of non-negligible (albeit small) quantum gravitational fluctuations [S. Liberati, S. Sonego, and M. Visser, Phys. Rev. D 71, 045001 (2005).][R. Aloisio, A. Galante, A. Grillo, S. Liberati, E. Luzio, and F. Mendez, Phys. Rev. D 73, 045020 (2006).]. In this paper we explicitly consider the case of a spacetime described by a flat metric endowed with stochastic fluctuations and, for a free particle, we show that DSR-like nonlinear relations between the spaces of the measured and classical momenta, can result from the average of the stochastic fluctuations over a scale set to be the de Broglie wavelength of the particle. As illustrative examples we consider explicitly the averaging procedure for some simple stochastic processes and discuss the physical implications of our results
Modified special relativity on a fluctuating spacetime
No full textIt was recently proposed that deformations of the relativistic symmetry, as those considered in deformed
special relativity (DSR), can be seen as the outcome of a measurement theory in the presence of nonnegligible
(albeit small) quantum gravitational fluctuations [S. Liberati, S. Sonego, and M. Visser, Phys.
Rev. D 71, 045001 (2005).][R. Aloisio, A. Galante, A. Grillo, S. Liberati, E. Luzio, and F. Mendez, Phys.
Rev. D 73, 045020 (2006).]. In this paper we explicitly consider the case of a spacetime described by a flat
metric endowed with stochastic fluctuations and, for a free particle, we show that DSR-like nonlinear
relations between the spaces of the measured and classical momenta, can result from the average of the
stochastic fluctuations over a scale set to be the de Broglie wavelength of the particle. As illustrative
examples we consider explicitly the averaging procedure for some simple stochastic processes and discuss
the physical implications of our results
Millerandage and flower abscission in ‘Grillo’, ‘Frappato’ and ‘Nero d’Avola’ grapevines: Some probable causes
No full textSome Sicilian cultivars, in particular vintage, showed a high percentage of flower abscissions and shot berries. In this paper, to understand these phenomena, some aspects of the flower morphology of three Sicilian cultivars (two black: ‘Nero d’Avola’ and ‘Frappato’; and one white: ‘Grillo’) was studied. The number of stamens, ovule adherence to the ovary wall and pollen germination were evaluated using standard light microscopy. At harvest, seed number was counted on 30 berries per cultivar. The percentage of six stamens was lowest in ‘Frappato’ and highest in ‘Grillo’. The ovule adherence to the ovary wall was highest in ‘Frappato’ and lowest in ‘Nero d’Avola’. The percentage of pollen germination and seed number was high in ‘Frappato’ while low in ‘Grillo’. Five or six stamens were found in all cultivars. These results could partially explain the different bunch density in ‘Nero d’Avola’, ‘Grillo’ and ‘Frappato’
"Pace, pace, morte ai dazi e alle gabelle" : il peso della guerra nella Lombardia del primo Trecento
No full textFor more than a quarter of a century, between 1311 and 1338, Lombardy was
shaken by civil clashes and major international conflicts, but the paper shows that
we must not overestimate the destructive power of these wars, because most of the
wages of mercenaries and booties were reintroduced into local economic circuits.
Indirect damage, such as the increase in taxes or the insecurity of trade, were
more serious problems, but after the early consolidation of the signoria of Azzone
Visconti, between 1329 and 1339, the region experienced a period of relative peace,
which made it possible to quickly recover the losses sustained in the previous years
and to avoid any long-term consequences
Fractional porous media equations: existence and uniqueness of weak solutions with measure data
No full textWe prove existence and uniqueness of solutions to a class of porous media equations driven by the fractional Laplacian when the initial data are positive finite Radon measures on the Euclidean space Rd. For given solutions without a prescribed initial condition, the problem of existence and uniqueness of the initial trace is also addressed. By the same methods we can also treat weighted fractional porous media equations, with a weight that can be singular at the origin, and must have a sufficiently slow decay at infinity (power-like). In particular, we show that the Barenblatt-type solutions exist and are unique. Such a result has a crucial role in Grillo et al. (Discret Contin Dyn Syst 35:5927–5962, 2015), where the asymptotic behavior of solutions is investigated. Our uniqueness result solves a problem left open, even in the non-weighted case, in Vázquez (J Eur Math Soc 16:769–803, 2014)
L’ecfrasi mistica nei «Pietosi affetti» di Angelo Grillo
No full textAnalisi del rapporto tra testo e immagine (nelle sue varie declinazioni) all'interno dei "Pietosi affetti" di Angelo Grillo, principale lirico sacro nell'età compresa tra Tasso e Marino
Le entrate signorili dei Mandelli a Maccagno: fine XIII-inizi XIV secolo
No full textIl saggio esamina la signoria esercitata dalla famiglia milanese dei Mandelli sul villaggio di Maccagno Inferiore, sul Lago Maggiore, a cavallo fra XIII e XIV secolo. Ne emerge il limitato rientro economico di questo territorio periferico, compensato però dal valore simbolico del potere ivi esercitato.The essay examines the lordship exercised by the Milanese Mandelli family over the village of Maccagno Inferiore, on the Lake Maggiore, between 13th and 14th centuries. This peripheral territory provided little wealth to the family, but this was compensated by the symbolic value of the power exercised
Le ragioni teoriche delle politiche di tutela della concorrenza
No full textIl lavoro analizza il ruolo ambito della politica di tutela della concorrenza nell'ambito del disegno di politica industrial
Indices-based Voltage Stability Monitoring of the Italian HV Transmission System
No full textIn liberalized electricity markets the need for an increasingly flexible and economic exploitation of the grid determines more and more stressed operating conditions. The on-line assessment of system security becomes a topic of paramount importance in control centers. In this context fast indices to quickly assess system security represent a valuable support for Transmission System Operators (TSOs). This paper presents the application of some (both node-oriented and line-oriented) indicators for the on-line voltage stability monitoring in the Italian HV transmission system. The implemented analysis tool is based on a procedure written in MATLAB which both retrieves the transients of the variables of interest from a time-domain simulator and composes these variables to calculate the monitoring indices. The combination of the information derived from the utilization of these indices allows to improve operators’ situational awareness concerning voltage stability issues. A dynamic model of the Italian HV transmission grid is presented and some simulation results concerning the indices application are illustrated and commented
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