arXiv subjects

Ignazio Licata

Publications and source records attributed to Ignazio Licata.

35 records · Page 2Linked to original sources

arXiv2013

On a Time-Space Operator (and other Non-Selfadjoint Operators) for Observables in QM and QFT

Aim of this paper is trying to show the possible significance, and usefulness, of various non-selfadjoint operators for suitable Observables in non-relativistic and relativistic quantum mechanics, and in quantum electrodynamics: More specifically, this work starts dealing with: (i) the hermitian (but not selfadjoint) Time operator in non-relativistic quantum mechanics and in quantum electrodynamics; with (ii) idem, with the introduction of Time and Space operators; and with (iii) the problem of the four-position and four-momentum operators, each one with its hermitian and anti-hermitian parts, for relativistic spin-zero particles. Afterwards, other physical applications of non-selfadjoint (and even non-hermitian) operators are briefly discussed. We mention how non-hermitian operators can indeed be used in physics [as it was done, elsewhere, for describing Unstable States]; and some considerations are added on the cases of the nuclear optical potential, of quantum dissipation, and in particular of an approach to the measurement problem in QM in terms of a "chronon". [This chapter is largely based on work developed, along the years, in collaboration with V.S.Olkhovsky, and, in smaller parts, with P.Smrz, with R.H.A.Farias, and with S.P.Maydanyuk]. PACS numbers: 03.65.Ta; 03.65.-w; 03.65.Pm; 03.70.+k; 03.65.Xp; 03.65.Yz; 11.10.St; 11.10.-z; 11.90.+t; 02.00.00; 03.00.00; 24.10.Ht; 03.65.Yz; 21.60.-u; 11.10.Ef; 03.65.Fd; 02.40.Dr; 98.80.Jk. Keywords: time operator, space-time operator, non-selfadjoint operators, non-hermitian operators, bilinear operators, time operator for discrete energy spectra, time-energy uncertainty relations, Klein-Gordon equation, chronon, quantum dissipation, decoherence, nuclear optical model, cosmology, projective relativity.

quant-ph↗

arXiv2011

Meta-Structural properties in Collective phenomena

In this contribution we consider Collective Behaviours as coherent sequences of spatial configurations adopted by interacting agents through corresponding different structures over time. Multiple structures over time and their sequences are considered as Meta-Structures establishing sequences of spatial configurations. They are intended as coherent when acquiring emergent properties. This coherence is considered here as being represented by the values adopted by suitable mesoscopic variables and their properties, i.e., meta-structural properties, allowing the researcher to a) Recognise a phenomenon as emergent; b) Induce emergence of collective behaviour in populations of agents collectively interacting; c) Act on collective emergent phenomena with the purpose to change, regulate and maintain acquired properties and d) Merge different collective emergent phenomena. We introduce a formal tool, i.e., the mesoscopic general vector to represent the adoption, over time, of mesoscopic properties by collectively interacting elements. We mention future experimental lines of activities, future lines of research and possible applications. Keywords: coherence, emergence, ergodicity, mesoscopic, meta-structures.

nlin.AO↗

arXiv2011

A Geometrical Manifold of Entropy for Fisher Information and Quantum Potential

It is here proposed a geometric approach for the problem of describing entropy in a quantum system. We make use of an extension of tensor calculus called morphogenetic calculus. By using such formalism we express the entropy of a quantum system as the superposition of Boltzmann entropies. In this way we also provide a reading of the relational interpretation of quantum mechanics. Moreover we show that the Bohm quantum potential emerges as a consequence of the classical equilibrium under the constraint of a minimum condition of Fisher information. In this way, Bohm quantum potential appears as a non-Euclidean deformation of the probabilistic space. Finally we investigate the possible quantum-relativistic extensions of the theory and the connections with the problem of quantum gravity.

quant-ph↗

arXiv2010

Living With Radical Uncertainty. The Exemplary case of Folding Protein

Laplace's demon still makes strong impact on contemporary science, in spite of the fact that Logical Mathematics outcomes, Quantum Physics advent and more recently Complexity Science have pointed out the crucial role of uncertainty in the World's descriptions. We focus here on the typical problem of folding protein as an example of uncertainty, radical emergence and a guide to the "simple" principles for studying complex systems.

physics.gen-ph↗

arXiv2010

Euclidean 5-sphere archaic universe

In this work, we examine in depth the cosmological physical aspects of the archaic universe described by Euclidean 5-sphere geometry. (see Int. Jour. of Theor., Phys 2009, 48:1003-1018). We hypothesize that the big bang consisted of a spatially extended nucleation process which took place at the end of a pre-cosmic phase, characterized by the evolution parameter x0. This parameter, which can be considered a quantum precursor of ordinary physical time, is a coordinate of Euclidean 5-sphere metrics. We must now examine what the privileged role of the x0 axis consists in. The big bang is a sort of nucleation of matter and fields by vacuum; to try to understand it we must therefore make some assumptions regarding a pre-cosmic state of matter and energy. The introduction of an evolution parameter such as x0 which can be extended to pre-big bang situations is absolutely necessary if we are to define any pre-cosmic dynamics. A generalized Bekenstein relation is here proposed for archaic Universe. A complete solution to Projective General Relativity (PGR) equations in the De Sitter Universe is provided, so as to establish univocal relations between the scale factor R(tau) and cosmic time tau. In this way, the physics and geometry of the cosmological model are specified completely.

physics.gen-ph↗

arXiv2009

Almost-anywhere Theories. Reductionism and Universality of Emergence

We aim here to show that reductionism and emergence play a complementary role in understanding natural processes and in the dynamics of science explanation. In particular, we will show that the renormalization group - one of the most refined tool of theoretical physics - allows understanding the importance of emergent processes' role in Nature identifying them universal organization processes, which is to say they are scale independent. We can use the syntaxes of Quantum Field Theory (QFT) and Spontaneous Symmetry Breaking as a trans-disciplinary theoretical scenario for many other forms of complexity, especially the biological and cognitive ones.

physics.gen-ph↗

arXiv2009

Quantum Computing in Non Euclidean Geometry

The recent debate on hyper-computation has raised new questions both on the computational abilities of quantum systems and the Church-Turing Thesis role in Physics. We propose here the idea of geometry of effective physical process as the essentially physical notion of computation. In Quantum mechanics we cannot use the traditional Euclidean geometry but we introduce more sophisticate non Euclidean geometry which include a new kind of information diffuse in the entire universe and that we can represent as Fisher information or active information. We remark that from the Fisher information we can obtain the Bohm and Hiley quantum potential and the classical Schrodinger equation. We can see the quantum phenomena do not affect a limited region of the space but is reflected in a change of the geometry of all the universe. In conclusion any local physical change or physical process is reflected in all the universe by the change of its geometry, This is the deepest meaning of the entanglement in Quantum mechanics and quantum computing. We stress the connection between metric and information as measure of change. Because computation is not restricted to calculus but is the environment changing via physical processes, super-Turing potentialities derive from an incomputable information source embedded into the geometry of the universe in accordance with Bell's constraints. In the general relativity we define the geometry of the space time. In our approach quantum phenomena define the geometry of the parameters of the probability distribution that include also the space time parameters. To study this new approach to the computation we use the new theory of Morphogenic systems.

physics.gen-ph↗

arXiv2008

Vision as Adaptive Epistemology

In the last years the debate on complexity has been developing and developing in transdisciplinary way to meet the need of explanation for highly organized collective behaviors and sophisticated hierarchical arrangements in physical, biological, cognitive and social systems. Unfortunately, no clear definition has been reached, so complexity appears like an anti-reductionist paradigm in search of a theory. In our short survey we aim to suggest a clarification in relation to the notions of computational and intrinsic emergence, and to show how the latter is deeply connected to the new Logical Openness Theory, an original extension of Godel theorems to the model theory. The epistemological scenario we are going to make use of is that of the theory of vision, a particularly instructive one. Vision is an element of our primordial relationship with the world;consequently it comes as no surprise that carefully taking into consideration the processes of visual perception can lead us straight to some significant questions useful to delineate a natural history of knowledge. The common Greek etymological root of theory and vision sounds like a metaphor pointing out the analogy between the modalities of vision and those we use to see and build the world because them both can say us something about the central role of the observer and the semantic complexity of cognitive strategies.

physics.gen-ph↗

arXiv2008

The Archaic Universe: Big Bang, Cosmological Term and the Quantum Origin of Time in Projective Cosmology

This article proposes some cosmological reflections at the qualitative and conjectural level, suggested by the Fantappie & Arcidiacono projective relativity theory. The difference will firstly be discussed between two types of singularity in this theory: geometric (de Sitter horizon) and physical (big bang, big crunch). The reasons for the existence of geometric singularities are deeply rooted in the principle of inertia and in the principle of relativity, while physical singularities are associated with the creation or destruction of matter. In this framework, quantum mechanics is introduced through a particular interpretation of Bohm holomovement. Finally, a possible mechanism is discussed for the genesis of the cosmological term. No form of inflation appears in the scenario described.

gr-qc↗

arXiv2008

A Dynamical Model for Information Retrieval and Emergence of Scale-Free Clusters in a Long Term Memory Network

The classical forms of knowledge representation fail when a strong dynamical interconnection between system and environment comes into play. We propose here a model of information retrieval derived from the Kintsch-Ericsson scheme, based upon a long term memory (LTM) associative net whose structure changes in time according to the textual content of the analyzed documents. Both the theoretical analysis carried out by using simple statistical tools and the tests show the appearing of typical power-laws and the net configuration as a scale-free graph. The information retrieval from LTM shows that the entire system can be considered to be an information amplifier which leads to the emergence of new cognitive structures. It has to be underlined that the expanding of the semantic domain regards the user-network as a whole system.

physics.gen-ph↗

arXiv2007

Emergence and Computation at the Edge of Classical and Quantum Systems

The problem of emergence in physical theories makes necessary to build a general theory of the relationships between the observed system and the observing system. It can be shown that there exists a correspondence between classical systems and computational dynamics according to the Shannon-Turing model. A classical system is an informational closed system with respect to the observer; this characterizes the emergent processes in classical physics as phenomenological emergence. In quantum systems, the analysis based on the computation theory fails. It is here shown that a quantum system is an informational open system with respect to the observer and able to exhibit processes of observational, radical emergence. Finally, we take into consideration the role of computation in describing the physical world.

physics.gen-ph↗

arXiv2007

Effective Physical Processes and Active Information in Quantum Computing

The recent debate on hypercomputation has arisen new questions both on the computational abilities of quantum systems and the Church-Turing Thesis role in Physics. We propose here the idea of "effective physical process" as the essentially physical notion of computation. By using the Bohm and Hiley active information concept we analyze the differences between the standard form (quantum gates) and the non-standard one (adiabatic and morphogenetic) of Quantum Computing, and we point out how its Super-Turing potentialities derive from an incomputable information source in accordance with Bell's constraints. On condition that we give up the formal concept of "universality", the possibility to realize quantum oracles is reachable. In this way computation is led back to the logic of physical world.

physics.gen-ph↗

arXiv2007

A New Model for the Organizational Knowledge Life Cycle

Actual organizations, in particular the ones which operate in evolving and distributed environments, need advanced frameworks for the management of the knowledge life cycle. These systems have to be based on the social relations which constitute the pattern of collaboration ties of the organization. We demonstrate here, with the aid of a model taken from the theory of graphs, that it is possible to provide the conditions for an effective knowledge management. A right way could be to involve the actors with the highest betweeness centrality in the generation of discussion groups. This solution allows the externalization of tacit knowledge, the preservation of knowledge and the raise of innovation processes.

physics.gen-ph↗

arXiv2007

Universe Without Singularities. A Group Approach to De Sitter Cosmology

In the last years the traditional scenario of Big Bang has been deeply modified by the study of the quantum features of the Universe evolution, proposing again the problem of using local physical laws on cosmic scale, with particular regard to the cosmological constant role. The group extention method shows that the De Sitter group univocally generalizes the Poincare group, formally justifies the cosmological constant use and suggests a new interpretation for Hartle-Hawking boundary conditions in Quantum Cosmology.

physics.gen-ph↗

arXiv2007

Evolutionary Neural Gas (ENG): A Model of Self Organizing Network from Input Categorization

Despite their claimed biological plausibility, most self organizing networks have strict topological constraints and consequently they cannot take into account a wide range of external stimuli. Furthermore their evolution is conditioned by deterministic laws which often are not correlated with the structural parameters and the global status of the network, as it should happen in a real biological system. In nature the environmental inputs are noise affected and fuzzy. Which thing sets the problem to investigate the possibility of emergent behaviour in a not strictly constrained net and subjected to different inputs. It is here presented a new model of Evolutionary Neural Gas (ENG) with any topological constraints, trained by probabilistic laws depending on the local distortion errors and the network dimension. The network is considered as a population of nodes that coexist in an ecosystem sharing local and global resources. Those particular features allow the network to quickly adapt to the environment, according to its dimensions. The ENG model analysis shows that the net evolves as a scale-free graph, and justifies in a deeply physical sense- the term gas here used.

physics.gen-ph↗

arXiv2007

General System theory, Like-Quantum Semantics and Fuzzy Sets

It is outlined the possibility to extend the quantum formalism in relation to the requirements of the general systems theory. It can be done by using a quantum semantics arising from the deep logical structure of quantum theory. It is so possible taking into account the logical openness relationship between observer and system. We are going to show how considering the truth-values of quantum propositions within the context of the fuzzy sets is here more useful for systemics . In conclusion we propose an example of formal quantum coherence.

physics.gen-ph↗

arXiv2007

Physics and Logical Openness in Cognitive Models

It is here proposed an analysis of symbolic and sub-symbolic models for studying cognitive processes, centered on emergence and logical openness notions.The Theory of Logical Openness connects the Physics of system/environment relationships to system informational structure. In this theory cognitive models can be ordered according to a hierarchy of complexity depending on their logical openness degree, and their descriptive limits are related to Godel-Turing Theorems on formal systems. The sysmbolic models with low logical openness describe cognition by means of semantics which fix the system/environment relationship (cognition in vitro), while the sub-symbolic ones with high logical openness tends to seize its evolutive dynamics (cognition in vivo. An observer is defined as a system with high logical openness. In conclusion, the characteristic processes of intrinsic emergence typical of bio-logic - emerging of new codes - require an alternative model to Turing Computation, the natural or bio-morphic computation, whose essential features we are going here to outline.

nlin.AO↗