Stefano Galatolo

ORCID: 0000-0003-3934-5412
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About
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Research Areas
  • Mathematical Dynamics and Fractals
  • Quantum chaos and dynamical systems
  • Chaos control and synchronization
  • Computability, Logic, AI Algorithms
  • Stochastic processes and statistical mechanics
  • Markov Chains and Monte Carlo Methods
  • Nonlinear Dynamics and Pattern Formation
  • Cellular Automata and Applications
  • Advanced Topology and Set Theory
  • Advanced Thermodynamics and Statistical Mechanics
  • Theoretical and Computational Physics
  • Statistical Mechanics and Entropy
  • Complex Systems and Time Series Analysis
  • Stochastic processes and financial applications
  • Fractal and DNA sequence analysis
  • Advanced Differential Equations and Dynamical Systems
  • Functional Equations Stability Results
  • Stability and Controllability of Differential Equations
  • Probabilistic and Robust Engineering Design
  • Mathematical and Theoretical Analysis
  • Algorithms and Data Compression
  • Topological and Geometric Data Analysis
  • Advanced Mathematical Modeling in Engineering
  • Muscle activation and electromyography studies
  • stochastic dynamics and bifurcation

University of Pisa
2015-2025

London Mathematical Laboratory
2022

Hokkaido University
2022

Huazhong University of Science and Technology
2020

University of Exeter
2020

Lund University
2020

Centre de Physique Théorique
2020

Centre de Développement des Technologies Avancées
2018

Laboratoire de Mathématiques de Bretagne Atlantique
2015

Laboratoire de Mathématiques d'Orsay
2015

Hardware security for an Internet of Things or cyber physical system drives the need ubiquitous cryptography to different sensing infrastructures in these fields. In particular, generating strong cryptographic keys on such resource-constrained device depends a lightweight and cryptographically secure random number generator. this research work, we have introduced new hardware chaos-based pseudorandom generator, which is mainly based deletion Hamilton cycle within N-cube (or vectorial...

10.1109/tii.2018.2815985 article EN IEEE Transactions on Industrial Informatics 2018-03-15

Abstract It is well known that a family of tent-like maps with bounded derivatives has no linear response for typical deterministic perturbations changing the value turning point. In this note we prove following result: if consider cusp at point, recover response. More precisely, let T ɛ be such generated by point 0 perturbation and h corresponding invariant density. We <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>ε</mml:mi> <mml:mo...

10.1088/1361-6544/ad4946 article EN cc-by Nonlinearity 2024-05-23

In a uniformly hyperbolic system, we consider the problem of finding optimal infinitesimal perturbation to apply from certain set $P$ feasible ones, maximally increase expectation given observation function. We perturb system both by composing with diffeomorphism near identity or adding deterministic dynamics. cases, using fast adjoint response formula, show that linear operator, which associates on dynamics, is bounded in terms $C^{1,\alpha}$ norm perturbation. Under assumption strictly...

10.48550/arxiv.2501.02395 preprint EN arXiv (Cornell University) 2025-01-04

We prove that if a non-autonomous system has in certain sense fast convergence to equilibrium (faster than any power law behavior), then the time τr(x,y) needed for typical point x enter first ball B(y,r) centered at y, with small radius r, scales as local dimension of measure μ i.e., limr→0log⁡τr(x,y)−log⁡r=dμ(y). apply general result concrete systems different kinds, showing such logarithm asymptotically autonomous solenoidal maps and mean field coupled expanding maps.

10.1063/5.0221721 article EN Chaos An Interdisciplinary Journal of Nonlinear Science 2025-02-01

Abstract We consider the problem of optimal linear response for deterministic expanding maps circle. To each infinitesimal perturbation <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mover> <mml:mi>T</mml:mi> <mml:mo>˙</mml:mo> </mml:mover> </mml:mrow> </mml:math> a circle map T we (i) expectation an observation function and (ii) isolated spectral points transfer operator . In case, under mild conditions on set feasible perturbations show there is...

10.1088/1361-6544/adac9c article EN Nonlinearity 2025-02-03

We consider a random dynamical system on $\mathbb{R}^d$, whose dynamics is defined by stochastic differential equation. The annealed transfer operator associated with such systems kernel operator. Given set of feasible infinitesimal perturbations $P$ to this kernel, support in certain compact set, and specified observable function $\phi: \mathbb{R}^d \to \mathbb{R}$, we study which perturbation produces the greatest change expectation $\phi$. establish conditions under optimal uniquely...

10.48550/arxiv.2502.09300 preprint EN arXiv (Cornell University) 2025-02-13

Abstract In this paper we prove that the Poincaré map associated to a Lorenz-like flow has exponential decay of correlations with respect Lipschitz observables. This implies hitting time satisfies logarithm law. The τ r ( x , 0 ) is needed for orbit point enter ball B centered at small radius first time. As decreases its asymptotic behavior power law whose exponent related local dimension physical measure : each such d μ exists, holds almost . similar way, it possible consider quantitative...

10.1017/s0143385709000856 article EN Ergodic Theory and Dynamical Systems 2009-12-11

We consider the question of computing invariant measures from an abstractpoint view. Here, a measure means finding algorithm which canoutput descriptions up to any precision. work in general framework (computable metric spaces) where this problem can be posed precisely. will find as fixed points transfer operator. In case, result ensures computability isolated computable map. give conditions under operator is on suitable set. This implies many 'regular enough' and among them physical...

10.3934/dcds.2011.29.193 article EN cc-by Discrete and Continuous Dynamical Systems 2010-09-24

We describe a framework in which it is possible to develop and implement algorithms for the approximation of invariant measures dynamical systems with given bound on error approximation. Our approach based general statement fixed points operators between normed vector spaces, allowing an explicit estimation error. show flexibility our by applying piecewise expanding maps indifferent points. how required estimations can be implemented compute densities up $L^{1}$ or $L^\infty $ distance. also...

10.1137/130911044 article EN SIAM Journal on Applied Dynamical Systems 2014-01-01

We prove the existence of noise induced order in Matsumoto–Tsuda model, where it was originally discovered 1983 by numerical simulations. This is a model famous Belousov–Zhabotinsky reaction, chaotic chemical and consists one dimensional random dynamical system with additive noise. The simulations showed that an increase amplitude causes Lyapunov exponent to decrease from positive negative; we give mathematical proof this transition. method use relies on some computer aided estimates...

10.1088/1361-6544/ab86cd article EN Nonlinearity 2020-07-22

We prove that if a system has superpolynomial (faster than any power law) decay of correlations then the time τ r (x, x 0 ) needed for typical point to enter first ball B(x , r) centered in with small radius scales as local dimension at i.e.This result is obtained by proving kind dynamical Borel-Cantelli lemma wich holds also systems having polinomial correlations.

10.4310/mrl.2007.v14.n5.a8 article EN Mathematical Research Letters 2007-01-01

We present a general setting in which the formula describing linear response of physical measure perturbed system can be obtained. In this we obtain an algorithm to rigorously compute response. apply our results expanding circle maps. particular, examples where compute, up pre-specified error -norm, maps under stochastic and deterministic perturbations. Moreover, example L1-norm, intermittent family at boundary; i.e. when unperturbed is doubling map.

10.1088/1361-6544/aa9a88 article EN Nonlinearity 2018-02-12

We consider transformations preserving a contracting foliation, such that the associated quotient map satisfies Lasota-Yorke inequality. prove transfer operator, acting on suitable normed spaces, has spectral gap (on which we have quantitative estimation). As an application Lorenz-like two dimensional maps (piecewise hyperbolic with unbounded contraction and expansion rate): those systems show estimate for their statistical stability. Under deterministic perturbations of system size...

10.3934/dcds.2020079 article EN Discrete and Continuous Dynamical Systems 2019-12-23

10.1016/s0019-3577(07)80031-0 article EN publisher-specific-oa Indagationes Mathematicae 2007-09-01

This paper introduces a method for detecting joint angles by using piezoresistive strain sensitive materials, as carbon loaded rubbers are. Materials used can be screen-printed onto fabrics to provide garments with sensing apparatus able reconstruct human postures and gestures. The main differences between this approach the previous ones, core of work, is rigorous proof that small local curvatures layers constituting electrogoniometers, resistance depends only on total curvature not...

10.1109/jsen.2009.2024867 article EN IEEE Sensors Journal 2009-07-29

We consider toral extensions of hyperbolic dynamical systems. prove that its quantitative recurrence (also with respect to given observables) and hitting time scale behavior depend on the arithmetical properties extension. By this we show those systems have a polynomial decay correlations $C^{r}$ observables, give estimations for exponent, which $r$ system. also examples kind having not shrinking target property, trivial limit distribution return statistics.

10.1017/etds.2014.10 article EN Ergodic Theory and Dynamical Systems 2014-07-03

We consider a general relation between fixed point stability of suitably perturbed transfer operators and convergence to equilibrium (a notion which is strictly related decay correlations). apply this deterministic perturbations class (piecewise) partially hyperbolic skew products whose behavior on the preserved fibration dominated by expansion base map. In particular, we results power law mixing toral extensions. It turns out that in case, dependence physical measure small perturbations,...

10.5802/jep.73 article EN cc-by Journal de l’École polytechnique — Mathématiques 2018-01-01

We show a linear response statement for fixed points of family Markov operators, which are perturbations mixing and regularizing operators. apply the to random dynamical systems on interval given by deterministic map T with additive noise (distributed according bounded variation kernel). prove these systems, also providing explicit formulas both changes in kernel. The holds mild assumptions system, allowing have critical points, contracting expanding regions. our theory topological maps...

10.1088/1361-6544/ab0c2e article EN Nonlinearity 2019-05-15

Quantitative recurrence indicators are defined by measuring the first entrance time of orbit a point x in decreasing sequence neighborhoods another y.It is proved that these a.e.greater or equal to local dimension at y.Moreover, estimation sharph if some mild assumptions on statistic return times satisfied.These can hence be used have an efficient numerical invariant measure.

10.4310/mrl.2005.v12.n3.a8 article EN Mathematical Research Letters 2005-01-01

We show an elementary method to obtain (finite time and asymptotic) computer assisted explicit upper bounds on convergence equilibrium (decay of correlations) escape rates for systems satisfying a Lasota Yorke inequality. The are deduced from the ones suitable approximations system's transfer operator. also present some rigorous experiments nontrivial example.

10.3934/jcd.2015.2.51 article EN Journal of Computational Dynamics 2015-01-01

We consider a class of maps from the unit square to itself preserving contracting foliation and inducing one-dimensional map having an absolutely continuous invariant measure. show how physical measure those systems can be rigorously approximated with explicitly given bound on error respect Wasserstein distance. present rigorous implementation our algorithm using interval arithmetics, result computation non-trivial example Lorenz-like two-dimensional its attractor, obtaining statement local...

10.1017/etds.2014.145 article EN Ergodic Theory and Dynamical Systems 2015-04-13
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