arXiv subjects

Silvia Morlacchi

Publications and source records attributed to Silvia Morlacchi.

7 recordsLinked to original sources

arXiv2026

Understanding the householder solar panel consumer: A Markovian model and its societal implications

Household adoption of rooftop photovoltaic (PV) systems is central to the green energy transition, yet diffusion depends on social influence and behavioral biases, as well as payback economics. This study develops a parsimonious Markovian model in which households move sequentially from being unengaged (Carbon) to informed, to planning, and finally to adoption (Green). Transition rates are micro-founded by two mechanisms: (i) social contagion/communication, proxied by the current share of adopters, and (ii) economic profitability, proxied by payback time computed from a Net Present Value framework. Novel to this diffusion setting, bounded rationality is introduced via hyperbolic discounting, creating a procrastination loop that delays adoption even when PV is economically attractive in a long-run perspective. Calibrated on the Italian residential PV diffusion path (2006-2020) and assessed in national and regional applications, the model reproduces observed trajectories and enables forward-looking scenario analysis (2020-2026). Results show that policies yielding similar payback improvements can produce different outcomes once present bias is accounted for and that behaviorally informed intervention are stronger. The findings contribute a micro-to-macro bridge between behavioral economics and technology diffusion modeling and imply that effective policy portfolios (and PV business models) should complement incentives with commitment devices and social-norm peer strategies to accelerate PV uptake and its spillover emissions benefits.

physics.soc-ph↗

arXiv2025

Homogenisation of a Passive Scalar Transported by Locally Supported White Noise

Stochastic perturbations of transport type are a common and widely accepted way of representing turbulent effects in fluid dynamics models. In many known examples, it even leads to improved solution theory, a phenomenon known as \emph{regularization by noise}. A common thread in the recent literature on the topic is the so-called \emph{Itô-Stratonovich diffusion limit}. By selecting Stratonovich transport noise with carefully arranged vector fields, one can show that the solution of certain SPDEs are close, in an appropriate topology, to an effective, deterministic, equation with a new effective second order elliptic operator, linked to the Ito-Stratonovich corrector. In this work, we deal with a passive scalar model with molecular diffusivity $κ$. Starting from the results in [Flandoli \emph{et al.}, 2022, \emph{Philos. Trans. Roy. Soc. A}, 380(2219)], we consider a transport noise made by a sum of independent and compactly supported vector fields. This setting is relevant for models of stratified turbulence which naturally occur in boundary layers and Boussinesq models. Due to the anisotropic nature of the noise, the identification of the limit equation is not straightforward as in all other examples known in literature, as the Ito-Stratonovich corrector is a generic second order elliptic operator with non-constant coefficients. Using tools from Homogenisation theory, we obtain a representation for the limiting effective diffusivity matrix. Exploiting this representation, we study asymptotics, in the $κ\rightarrow 0$ regime, of the effective diffusivity across a number of vector field regimes parametrised by the radius of their support. Finally, we provide a careful numerical analysis of the effective diffusivity, discovering a nonlinear behavior for $κ\rightarrow 0$, in some regimes.

math.AP↗

arXiv2025

Structural properties in the diffusion of the solar photovoltaic in Italy: individual people/householder vs firms

This paper develops two mathematical models to understand subjects' behavior in response to the urgency of a change and inputs from governments e.g., (subsides) in the context of the diffusion of the solar photovoltaic in Italy. The first model is a Markovian model of interacting particle systems. The second one, instead, is a Mean Field Game model. In both cases, we derive the scaling limit deterministic dynamics, and we compare the latter to the Italian solar photovoltaic data. We identify periods where the first model describes the behavior of domestic data well and a period where the second model captures a particular feature of data corresponding to companies. The comprehensive analysis, integrated with a philosophical inquiry focusing on the conceptual vocabulary and correlative implications, leads to the formulation of hypotheses about the efficacy of different forms of governmental subsidies.

physics.soc-ph↗

arXiv2025

Decay of Time Correlations in Point Vortex Systems

The dynamics of a large point vortex system whose initial configuration consists in uniformly distributed independent positions is investigated. Time correlations of local observables of the vortex configuration are shown to be compatible with power law decay 1/t, providing additional insight on ergodicity and mixing properties of equilibrium dynamics in point vortex models.

physics.flu-dyn↗

arXiv2023

Effect of Transport Noise on Kelvin-Helmholtz instability

The effect of transport noise on a 2D fluid may depend on the space-scale of the noise. We investigate numerically the dissipation properties of very small-scale transport noise. As a test problem we consider the Kelvin-Helmholtz instability and we compare the inviscid case, the viscous one, both without noise, and the inviscid case perturbed by transport noise. We observe a partial similarity with the viscous case, namely a delay of the instability.

physics.flu-dyn↗

arXiv2021

The unreasonable effectiveness of effective string theory: the case of the 3d SU(2) Higgs model

We study string breaking in the three dimensional SU(2) Higgs model, using values of the gauge coupling for which the confinement-like and Higgs-like regions of the phase diagram are separated just by a smooth crossover. We show that even in the presence of string breaking, the confining part of the interquark potential is well described by the Effective String Theory and that also the fine details of the effective string, like the higher order terms of the Nambu-Goto action or the boundary correction, can be precisely extracted from the fits and agree with the effective string predictions. We comment on the implications of these results for QCD simulations with dynamical quarks.

hep-lat↗

arXiv2020

Flux tubes and string breaking in three dimensional SU(2) Yang-Mills theory

We consider the three dimensional SU(2) Yang-Mills theory with adjoint static color sources, studying by lattice simulations how the shape of the flux tube changes when increasing the distance between them. The disappearance of the flux tube at string breaking is quite abrupt, but precursors of this phenomenon are present already when the separation between the sources is smaller than its critical value, a fact that influences also some details of the static potential.

hep-lat↗