arXiv subjects
Publications and source records attributed to Maria K. Koleva.
General criterion for best efficiency of the interaction of a complex system with an ever-changing environment is derived. Its exclusive property, set by boundedness, is that the highly non-trivial interplay between parameters that participate in it renders the best survival strategy to go via non-extensive hierarchical super-structuring of the semantic-like response.
It is demonstrated that under the hypothesis of boundedness, the semantics appears as a property of spontaneous physical processes. It turns that both semantic structure and semantic meaning have their own physical agents each of which is represented trough generic for the state space property. The boundedness sets an exclusive two-fold representation of a semantic unit: as a specific sequence of letters and as a performance of a specific engine so that their interplay serves as grounds for building a multi-layer hierarchy of semantic structures. It is established that in this setting the semantics admits both non-extensivity, permutation sensitivity and Zipf`s law. The robustness of the hierarchical organization of semantic structures is maintained by new generic form of non-local feedback that appears as a result of the necessary for sustaining boundeness matter wave emitting.
A complex interplay between the academic issue about generalization of the thermodynamics and the practical matter about setting standards for a sustainable evolution of both tailored devices and natural systems is considered. It is established that the measure for a sustainable evolution in an ever-changing environment appears as a Boltzmann-Gibbs weight. At the same time, this measure performs as a local thermodynamical potential which, at the expense of being released from the condition of entropy maximization, serves as grounds for a fundamental development of the idea of banning perpetuum mobile. It is proven that the best efficiency of each engine that operates reversibly never exceeds the efficiency of corresponding Carnot heat engine where the engine is free from necessity of a physical coupling to two heat reservoirs.
A new approach to complex systems aimed to resolve their paradoxes is proposed. Yet, the major inference is the prohibition of informational perpetuum mobile
The problem of the insensitivity of the macroscopic behavior of any thermodynamical system to partitioning generates a bias between the reproducibility of its macroscopic behavior viewed as the simplest form of causality and its long-term stability. The overcoming of this controversy goes through certain modification of the dynamics that involves self-assembling of the boundary conditions. Subsequently the proposed approach justifies parity between the increase and the decrease of the entropy which provides the ground for holistic understanding of the thermodynamical systems through launching their ability to transmit and create information that is sensitive to coherent functioning of self-assembled logical landscapes. The obtained sensitivity gives the advantage of this new approach compared to that of Shannon. According to his definition, the information depends only on the overall probability for realization of a given state(s) and thus it does not distinguish between functionally different states provided the overall probability for the realization of each of them is equal.
Major revision of the thermodynamics is made in order to provide rigorous fundament for functional diversity of holistic type. It turns out that the new approach ensures reproducibility of the information as well.
The properties of the fluctuations large enough to induce bifurcations at open chemical systems at steady constraints are studied. The fluctuations that come from the diffusion-induced noise are considered. It is a generic for the surface reactions driving mechanism of fluctuations whose distinctive property is that it generates bounded fluctuations at any value of the control parameters. The range of boundedness is specific to a system but it is such that the system permanently stays within its thresholds of stability. This in turn ensures long-term stable evolution of the system. The frequency for occurrence of an induced bifurcation is carried out analytically. Its important property is that it gradually becomes insensitive to the reaction mechanism on increasing the excursion size.
The idea that the velocity of transmitting substance/energy trough space-time is to be bounded is a fundamental concept in the science. To the most surprise, it turns out that it is not always met. We demonstrate that the existing approaches to the self-organization, another major concept in the science, let the velocity of transmitting substance to be arbitrary. Further we prove that only the boundedness of the velocity is not enough to ensure the self-organization. That is why we develop radically novel approach to the macroscopic evolution that not only reconciles the self-organization and the velocity ansatz but in addition gives physically credible basis to phenomena like Feigenbaum cascade and fluctuation-assisted bifurcations.
Exerting fluctuations is a part of our daily life: traffic noise, heartbeat, opinion poll, currency exchange rate, electrical current, chemical reactions - they all permanently fluctuate. One of the most important questions is why the systems that exert fluctuations stay long-term stable. Is there any general functional relation that provides long-term stability despite the wide diversity of the fluctuations commence: emotions, economics, physical interactions etc? I assert that such functional relation does exist and reveal its specification: the route to the long-term stability is through coherence and boundedness as necessary conditions. It is demonstrated that the chaoticity is the hallmark of that relationship. The present contribution is a systematic study written as a book on the relation between long-term stability and exerting macroscopic fluctuations. Further attention is focused on the mechanism that guarantees the boundedness and the coherence of the local fluctuations in the physical systems. Crucial arguments that neither of the existing so far approaches to the behavior of the extended many-body systems provides boundedness and coherence of the fluctuations are put forward. It turns out that the mechanism that brings about macroscopic fluctuations has universal properties and entangles quantum decoherence, chaos and 1/f noise in a tricky interplay.
Two crucial for the breakdown of the master equation arguments are put forward. The first one is related to the violence of a fundamental requirement to the notion of state (thermodynamical) variable, namely: a state variable is defined provided it is insensitive to the particularities of the spatio-temporal configurations upon which the averaging over the dynamical variables proceeds. The second one is related to a ubiquitous divergence of the scattering length in the low-energy limit. In turn, it makes the rates of all the elementary processes divergent as well. Though radically novel viewpoints to the low-energy limit and to the evolution ensure the boundedness of the rates and hold the notion of a state variable available, the master equation remains inappropriate.
A local quantum phenomenon that gives rise to generic for all surface reactions macroscopic fluctuations is studied. The issue is viewed with respect to the necessary conditions for a long-term stable evolution of any natural and artificial system. It is shown that global coupling of the local fluctuations is necessary for providing a long-term stability of the system. A successful coupling mechanism is achieved on the grounds of new assumptions about the Hamiltonian response to certain perturbations. The coupling mechanism acts towards a global synchronisation, i.e. to a coherent response of the excited species to any further perturbation. It is proven that the synchronisation is a scale-free process that has universal properties, e.g. it is insensitive to the chemical identity of the reacting species and to the particularities of the surface reaction. Its hallmark is that the global adsorption rate exhibits permanent temporal variations whose amplitude is independent of the system size. The presence of these fluctuations fundamentally changes the temporal behavior of the system, namely it becomes pulse-like both on the quantum and the macro-level. The pulse-like behavior gives rise to a persistent continuous band at the quantum spectra whose major properties are: (I) it does not correspond to any real radiation; (ii) its presence is insensitive to the particularities of the system and the incident radiation; (iii) its shape and the infrared edge are typical for the -type noise. These properties give rise to its name: alias -type noise.
Our recent interest is focused on establishing the necessary and sufficient conditions that guarantee a long-term stable evolution of both natural and artificial systems. Two necessary conditions, called global and local boundedness, are that a system stays stable if and only if the amount and the rate of exchange of energy and/or matter currently involved in any transition do not exceed the thresholds of stability of the system. The relationship between the local and global boundedness and the stability of the system introduces two new general properties of the state space and the motion in it, namely: the state space is always bounded, the successive steps of motion are always finite and involve only nearest neighbors. An immediate consequence of the boundedness is that the invariant measure of the state space is the normal distribution. The necessary condition for the asymptotic stability of the invariant measure is derived. It is found out that the state space exhibits strong chaotic properties regardless to the particularities of the system considered. An example of kinetics that is compatible with both global and local boundedness is considered.
The major goal of the present paper is to find out the manifestation of the boundedness of fluctuations. Two different subjects are considered: (i) an ergodic Markovian process associated with a new type of large scaled fluctuations at spatially homogeneous reaction systems; (ii) simulated dynamical systems that posses strange attractors. Their common property is that the fluctuations are bounded. It is found out that the mathematical description of the stochasity at both types of systems is identical. Then, it is to be expected that it exhibits certain common features whose onset is the stochasticity, namely: (i) The power spectrum of a time series of length $T$ comprises a strictly decreasing band that uniformly fits the shape $1/f^α(f)$ where $α(1/T)=1$ and $α(f)$ strictly increases to the value $α(\inf)=p$ ($p>2$) as $f$ approaches infinity. Practically, at low frequencies this shape is $1/f$-like with high accuracy because the deviations of the non-constant exponent $α(f)$ from 1 are very small and become even smaller as the frequency tends to 1/T. The greatest advantage of the shape $1/α(f)$ is that it ensures a finite variance of the fluctuations. (ii) It is found out that the structure of a physical and strange attractor is identical and they are non-homogeneous. (iii) The Kolmogorov entropy is finite.
The structure of the physical and strange attractors is inherently associated with the boundedness of fluctuations. The idea behind the boundedness is that a stable long-term evolution of any natural and engineered system is possible if and only if the fluctuations that the system exerts are bounded so that the system permanently stays within its thresholds of stability. It has been established that the asymptotic structure of the physical and strange attractors is identical. Now it is found out that though the non-asymptotic behavior is universal it can be very different, namely: on coarse-graining the physical attractors can exhibit a variety of behavior while the strange attractors always have hyperuniversal properties. Yet, under certain levels of coarse-graining both physical and strange attractors match non-asymptotically a variety of noise type behavior.
It is found out that there are physical effects, typical of small metal clusters deposited on a non-adsorbing support, that cause a difference between the adsorption properties of sites at the metal cluster surface and those of sites at the boundary of metal-support. This difference gives rise to an extra band in the IR spectra of the adsorbate whose major property is that its intensity changes with cluster size. The migration of chemisorbed molecules (atoms, ions) and molecules (atoms, ions) in any excited state over adsorption sites of different type results in changes in the state of the molecule (atom, ion) since the latter adjusts its state to the set of levels of another type of site. This can be described figuratively as a transformation of the type of adsorption site. Thus, a single type of adsorption site, called next surface effective site (SES), is formed. The energy of desorption from SES site retains an explicit dependence on the metal cluster size. A simulation of TPD spectra of oxygen desorption from small Pt clusters deposited on NaX zeolite was carried out. A comparison to experimental TPD spectra obtained by Jaeger and co-workers for the same system is made.