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Introduction to the modern theory of Dynamical Systems

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... The purpose of this paper is to present a convergence analysis for Carleman linearization without the dissipative condition. One of our key contributions is the identification of another type of condition, called the no-resonance condition, motivated by the theory of dynamical systems [25]. Roughly speaking, this condition states that any one eigenvalue can not coincide with an integer combination of other eigenvalues. ...
... Therefore, for non-dissipative systems, ∆ in Eq. (3) plays a similar role to |σ| in the convergence rate in the dissipative regime Eq. (2). Resonance properties play a crucial role in the long-time behavior of dynamical systems, including phenomena such as bifurcation, chaos, and energy transport [10,25]. Important examples include Fermi-Pasta-Ulam (FPU) chains [34], the nonlinear Schrödinger equation [4], and the Korteweg-de Vries (KdV) equation [18]. ...
... In the theory of dynamical systems [25], the first part of the assumption comes from stability consideration, but we do not rule out non-hyperbolic equilibrium points. Meanwhile, the condition in Eq. (9) is known as the no-resonance condition. ...
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In this paper, we explore the embedding of nonlinear dynamical systems into linear ordinary differential equations (ODEs) via the Carleman linearization method. Under dissipative conditions, numerous previous works have established rigorous error bounds and linear convergence for Carleman linearization, which have facilitated the identification of quantum advantages in simulating large-scale dynamical systems. Our analysis extends these findings by exploring error bounds beyond the traditional dissipative condition, thereby broadening the scope of quantum computational benefits to a new class of dynamical regimes. This novel regime is defined by a resonance condition, and we prove how this resonance condition leads to a linear convergence with respect to the truncation level $N$ in Carleman linearization. We support our theoretical advancements with numerical experiments on a variety of models, including the Burgers' equation, Fermi-Pasta-Ulam (FPU) chains, and the Korteweg-de Vries (KdV) equations, to validate our analysis and demonstrate the practical implications.
... The aim of this paper is the investigation of the topological dynamics of automorphisms on a 6-dimensional torus generated by an integer symplectic transformation of R 6 in the case of partial hyperbolicity. The hyperbolic case is rather well understood already [1,10,26,18]. ...
... Since the linear mapping L A : x → Ax maps the subgroup Z n onto itself, such a matrix generates a diffeomorphism f A of the torus T n called an automorphism of the torus [1,2,10]. Topological properties of such maps are the classical object of research (see, for example, [1,10,18,26]). Because this toral automorphism also preserves the standard volume element dx 1 ∧ · · · ∧ dx n on the torus carried over from R n , its ergodic properties have also been the subject of research [5,12,28]. ...
... [21,Ch. XIX], [19, ch. 8 & 9], [20], and [30]). ...
... So we have two different representations of trajectories, σ in (15) and α tr (σ) in (17), this second representation being closer to the time-evolution law of the theory of dynamical systems [20]. Notice that α tr (σ) is a function defined by parts on the timeline abstraction α tl (σ) of the trajectory σ so the time-evolution law α tr (σ) is not simpler that the trajectory σ to reason upon, in particular because the timeline information is abstracted away. ...
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We formalize the semantics of hybrid systems as sets of hybrid trajectories, including those generated by an hybrid transition system. We study the abstraction of hybrid trajectory semantics for verification, static analysis, and refinement. We mainly consider abstractions of hybrid semantics which establish a correspondence between trajectories derived from a correspondence between states such as homomorphisms, simulations, bisimulations, and preservations with progress. We also consider abstractions that cannot be defined stepwise like discretization. All these abstractions are Galois connections between concrete and abstract hybrid trajectory or discrete trace semantics. In contrast to semantic based abstractions, we investigate the problematic trace-based composition of abstractions.
... The study of MAP systems dynamics is also related to the areas of Dynamical Systems (e.g. [20]) and Statistical Physics (e.g. [21,22,23]). ...
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A large number of real and abstract systems involve the transformation of some basic resource into respective products under the action of multiple processing agents, giving rise to multiple-agent production systems (MAP). At each discrete time instant, for each agent, a fraction of the resources is assumed to be kept, forwarded to other agents, or converted into work/wasted. The present work describes a systematic study of nine basic MAP architectures subdivided into two main groups, namely parallel and sequential distribution of resources from a single respective source. Several types of interconnec-tions among the involved processing agents are also considered. The resulting MAP architectures are studied in terms of the total amount of work, the dispersion of the resources (states) among the agents, and the transition times from the start of operation until the respective steady state. Several interesting results are obtained and discussed, including the observation that some of the parallel designs have were able to yield maximum work and minimum states dispersion, achieved at the expense of the transition time and use of several interconnec-tions between the source and the agents. The performance obtained for the sequential designs indicated that relatively high performance can be obtained for some specific cases.
... Therefore, weak perturbations of the system from external sources may 40 cause a state of change due to the critical point, where the system will evolve into the 41 new stable or unstable state. The proposed mechanism of control ensures that the 42 system remains stable, in the Lyapunov sense [9], but with uniquely different stable 43 states. 44 Small interactions within the components of a SOC system are not significantly 45 large with respect to the scale of each element, but they contribute to the global 46 critical state due to nonlinear behaviour. ...
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The control of extensive complex biological systems is considered to depend on feedback mechanisms. Reduced systems modelling has been effective to describe these mechanisms, but this approach does not sufficiently encompass the required complexity that is needed to understand how localised control in a biological system can provide global stable states. Self-Organised Criticality (SOC) is a characteristic property of locally interacting physical systems which readily emerges from changes to its dynamic state due to small nonlinear perturbations. Small changes in the local states, or in local interactions, can greatly affect the total system state of critical systems. It has long been conjectured that SOC is cardinal to biological systems that show similar critical dynamics and also may exhibit near power-law relations. Rate Control of Chaos (RCC) provides a suitable robust mechanism to generate SOC systems which operates at the edge of chaos. The bio-inspired RCC method requires only local instantaneous knowledge of some of the variables of the system, and is capable of adapting to local perturbations. Importantly, connected RCC controlled oscillators can maintain global multi-stable states, and domains with power-law relations may emerge. The network of oscillators deterministically stabilises into different orbits for different perturbations and the relation between the perturbation and amplitude can show exponential and power-law correlations. This is representative of a basic mechanism of protein production and control, that underlies complex processes such as homeostasis. Providing feedback from the global state, the total system dynamic behaviour can be boosted or reduced. Controlled SOC can provide much greater understanding of biological control mechanisms, that are based on distributed local producers, remote consumers of biological resources, with globally defined control. Author summary Using a nonlinear control method inspired by enzymatic control, which is capable of stabilising chaotic systems into periodic orbits or steady-states, it is shown that a controlled system can be created that is scale-free and in a critical state. This means that the system can easily move from one stable orbit to another using only a small local perturbation. Such a system is known as self-organised criticality, and is shown in this system to be deterministic. Using a known perturbation, it will result in a scale-free response of the system that can be in a power law relation. It has been conjectured that biosystems are in a self-organised critical state, and these models show that this is a suitable approach to allow local systems to control a global state, such as homeostatic control. The underlying principle is based on rate control of chaos, and can be used to understand how biosystems can use localised control to ensure stability at different dynamic scales without supervising mechanisms.
... Let T be an orientation-preserving circle homeomorphism. If the rotation number ρ of T is rational, then every orbit of T converges to a periodic orbit (see for instance [70,Proposition 11.2.2]). By Theorem 1 in [38], the oscillating sequence (c n ) n∈N is orthogonal to the system (S 1 , T ). ...
Thesis
In this thesis, we solve Fuglede's conjecture on the field of p-adic numbers, and study some randomness and the oscillating properties of sequences related to Sarnak's conjecture. In the first part, we first prove Fuglede's conjecture for compact open sets in the field Q_p which states that a compact open set in Q_p is a spectral set if and only if it tiles Q_p by translation. It is also proved that a compact open set is a spectral set (or a tile) if and only if it is p-homogeneous. We characterize spectral sets in Z/p^n Z (p>1 prime, n>0 integer) by tiling property and also by homogeneity. Finally, we prove Fuglede's conjecture in Q_p without the assumption of compact open sets and also show that the spectral sets (or tiles) are the sets which differ by null sets from compact open sets. In the second part, we first give several equivalent definitions of oscillating sequences in terms of their disjointness from different dynamical systems on tori. Then we define Chowla property and Sarnak property for numerical sequences taking values 0 or complex numbers of modulus 1. We prove that Chowla property implies Sarnak property. It is also proved that for Lebesgue almost every b>1, the sequence (e^{2 pi b^n})_{n in N} shares Chowla property and consequently is orthogonal to all topological dynamical systems of zero entropy. We also discuss whether the samples of a given random sequence have almost surely Chowla property. Some dependent random sequences having almost surely Chowla property are constructed
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Based on the Schweiger’s smooth fibered approach and the related Bernoulli shift transformation scheme, we prove the ergodicity of the two-dimensional Boole-type transformations. New multidimensional Boole-type transformations invariant with respect to the Lebesgue measure and their ergodicity properties are also discussed.
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This work offers a comprehensive and fresh perspective on the bonding evolution theory (BET) framework, originally proposed by Silvi and collaborators [X. Krokidis, S. Noury and B. Silvi, Characterization of elementary chemical processes by catastrophe theory, J. Phys. Chem. A, 1997, 101, 7277-7282]. By underscoring Thom's foundational work, we identify the parametric function characterizing bonding events along a reaction pathway through a three-step sequence to establish such association rigorously, namely: (a) computing the determinant of the Hessian matrix at all potentially degenerate critical points, (b) computing the relative distance between these points, and (c) assigning the unfolding based on these computations and considering the maximum number of critical points for each unfolding. In-depth examination of the ammonia inversion and the dissociation of ethane and ammonia borane molecules yields a striking discovery: no elliptic umbilic flag is detected along the reactive coordinate for any of the systems, contradicting previous reports. Our findings indicate that the core mechanisms of these chemical reactions can be understood using only two folds, the simplest polynomial of Thom's theory, leading to considerable simplification. In contrast to previous reports, no signatures of the elliptic umbilic unfolding were detected in any of the systems examined. This finding dramatically simplifies the topological rationalization of electron rearrangements within the BET framework, opening new approaches for investigating complex reactions.
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