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Journal articles on the topic 'Quantum theories as models of complexity'

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Author: Grafiati

Published: 4 June 2021

Last updated: 3 February 2022

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1

Pagliaro, Gioacchino, and Linda Marconi. "The Holistic Mind: The Necessity Of A New Epistemology." Integral Transpersonal Journal 8, no. 8 (June 2016): 58. http://dx.doi.org/10.32031/itibte_itj_8-pgml3.

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In the second half of the last century the continuous development of hypotheses, theories and models from different disciplines has made several changes in the epistemological structure of cognitive science. This profoundly changed the mechanistic vision of the previous accepted model. The birth of a holistic epistemological paradigm-that considers the human body as a network of integrated communication- increases its relevance in Western scientific world, embracing a vision of close interconnection and interdependence between mind and body. The epistemology of complexity is the fundamental starting point for a proper study of human being and of human knowledge. In addition, it represents a meeting point between Eastern medical tradition and the current scientific conceptions from quantum physics, favoring the integration of care and prevention systems in psychology and medicine. KEYWORDS Epistemology, complexity, holism, extended mind, quantum physics.

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2

Chaves, Rafael, Daniel Cavalcanti, and Leandro Aolita. "Causal hierarchy of multipartite Bell nonlocality." Quantum 1 (August 4, 2017): 23. http://dx.doi.org/10.22331/q-2017-08-04-23.

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As with entanglement, different forms of Bell nonlocality arise in the multipartite scenario. These can be defined in terms of relaxations of the causal assumptions in local hidden-variable theories. However, a characterisation of all the forms of multipartite nonlocality has until now been out of reach, mainly due to the complexity of generic multipartite causal models. Here, we employ the formalism of Bayesian networks to reveal connections among different causal structures that make a both practical and physically meaningful classification possible. Our framework holds for arbitrarily many parties. We apply it to study the tripartite scenario in detail, where we fully characterize all the nonlocality classes. Remarkably, we identify new highly nonlocal causal structures that cannot reproduce all quantum correlations. This shows, to our knowledge, the strongest form of quantum multipartite nonlocality known to date. Finally, as a by-product result, we derive a non-trivial Bell-type inequality with no quantum violation. Our findings constitute a significant step forward in the understanding of multipartite Bell nonlocality and open several venues for future research.

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3

Crumpei, Gabriel, and Alina Gavriluţ. "Emergence, a Universal Phenomenon which Connects Reality to Consciousness, Natural Sciences to Humanities." Human and Social Studies 7, no. 2 (June 1, 2018): 89–106. http://dx.doi.org/10.2478/hssr-2018-0017.

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Abstract Progress in neuroscience has left a central question of psychism unanswered: what is consciousness? Modeling the psyche from a computational perspective has helped to develop cognitive neurosciences, but it has also shown their limits, of which the definition, description and functioning of consciousness remain essential. From Rene Descartes, who tackled the issue of psychism as the brain-mind dualism, to Chambers, who defined qualia as the tough, difficult problem of research in neuroscience, many hypotheses and theories have been issued to encompass the phenomenon of consciousness. Neuroscience specialists, such as Giulio Tononi or David Eagleman, consider consciousness as a phenomenon of emergence of all processes that take place in the brain. This hypothesis has the advantage of being supported by progress made in the study of complex systems in which the issue of emergence can be mathematically formalized and analyzed by physical-mathematical models. The current tendency to associate neural networks within the broad scope of network science also allows for a physical-mathematical formalization of phenomenology in neural networks and the construction of information-symbolic models. The extrapolation of emergence at the level of physical systems, biological systems and psychic systems can bring new models that can also be applied to the concept of consciousness. The meaning and significance that seem to structure the nature of consciousness is found as direction of evolution and teleological finality, of integration in the whole system and in any complex system at all scales. Starting from the wave-corpuscle duality in quantum physics, we can propose a model for structuring reality, based on the emergence of systems that contribute to the integration and coherence of the entire reality. Physical-mathematical models based mainly on (mereo)topology can provide a mathematical formalization path, and the paradigm of information could allow the development of a pattern of emergence, that is common to all systems, including the psychic system, the difference being given only by the degree of information complexity. Thus, the mind-brain duality, which has been dominating the representation on psychism for a few centuries, could be solved by an informational approach, describing the connection between object and subject, reality and human consciousness, between mind and brain, thus unifying the perspective on natural sciences and humanities.

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4

Goncharov, S. S., and B. Khoussainov. "Complexity of Categorical Theories with Computable Models." Algebra and Logic 43, no. 6 (November 2004): 365–73. http://dx.doi.org/10.1023/b:allo.0000048826.92325.02.

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5

Keski-Vakkuri, E., A. J. Niemi, G. Semenoff, and O. Tirkkonen. "Topological quantum theories and integrable models." Physical Review D 44, no. 12 (December 15, 1991): 3899–905. http://dx.doi.org/10.1103/physrevd.44.3899.

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6

Byrne, David, Raymond A. Eve, Sara Horsfall, Mary E. Lee, and Alan Dean. "Chaos, Complexity and Sociology: Myths, Models and Theories." British Journal of Sociology 49, no. 3 (September 1998): 501. http://dx.doi.org/10.2307/591399.

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7

Ageev, Dmitry. "Holography, quantum complexity and quantum chaos in different models." EPJ Web of Conferences 191 (2018): 06006. http://dx.doi.org/10.1051/epjconf/201819106006.

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This contribution to Quarks’2018 conference proceedings is based on the talk presenting papers [1, 2] at the conference. These papers are devoted to the holographic description of chaos and quantum complexity in the strongly interacting systems out of equilibrium. In the first part of the talk we present different holographic complexity proposals in out-of-equilibrium CFT following the local perturbation. The second part is devoted to the chaotic growth of the local operator at a finite chemical potential. There are numerous results stating that the chemical potential may lead to the chaos disappearance, and we confirm the results from holography.

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8

Witten, Edward. "Gauge theories, vertex models, and quantum groups." Nuclear Physics B 330, no. 2-3 (January 1990): 285–346. http://dx.doi.org/10.1016/0550-3213(90)90115-t.

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9

Jordan, Stephen P., Keith S. M. Lee, and John Preskill. "Quantum computation of scattering in scalar quantum field theories." Quantum Information and Computation 14, no. 11&12 (September 2014): 1014–80. http://dx.doi.org/10.26421/qic14.11-12-8.

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Quantum field theory provides the framework for the most fundamental physical theories to be confirmed experimentally and has enabled predictions of unprecedented precision. However, calculations of physical observables often require great computational complexity and can generally be performed only when the interaction strength is weak. A full understanding of the foundations and rich consequences of quantum field theory remains an outstanding challenge. We develop a quantum algorithm to compute relativistic scattering amplitudes in massive $\phi^4$ theory in spacetime of four and fewer dimensions. The algorithm runs in a time that is polynomial in the number of particles, their energy, and the desired precision, and applies at both weak and strong coupling. Thus, it offers exponential speedup over existing classical methods at high precision or strong coupling.

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10

RANDJBAR-DAEMI, S., ABDUS SALAM, and J. A. STRATHDEE. "σ-MODELS AND STRING THEORIES." International Journal of Modern Physics A 02, no. 03 (June 1987): 667–93. http://dx.doi.org/10.1142/s0217751x87000247.

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The propagation of closed bosonic strings interacting with background gravitational and dilaton fields is reviewed. The string is treated as a quantum field theory on a compact 2-dimensional manifold. The question is posed as to how the conditions for the vanishing trace anomaly and the ensuing background field equations may depend on global features of the manifold. It is shown that to the leading order in σ-model perturbation theory the string loop effects do not modify the gravitational and the dilaton field equations. However for the purely bosonic strings new terms involving the modular parameter of the world sheet are induced by quantum effects which can be absorbed into a re-definition of the background fields. We also discuss some aspects of several regularization schemes such as dimensional, Pauli-Villars and the proper-time cut off in an appendix.

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11

BELIAKOVA, ANNA. "SPIN TOPOLOGICAL QUANTUM FIELD THEORIES." International Journal of Mathematics 09, no. 02 (March 1998): 129–52. http://dx.doi.org/10.1142/s0129167x98000099.

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Starting from the quantum group [Formula: see text], we construct operator invariants of 3-cobordisms with spin structure, satisfying the requirements of a topological quantum field theory and refining the Reshetikhin–Turaev and Turaev–Viro models. We establish the relationship between these two refined theories.

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12

Lechner, Gandalf. "Deformations of Quantum Field Theories and Integrable Models." Communications in Mathematical Physics 312, no. 1 (December 3, 2011): 265–302. http://dx.doi.org/10.1007/s00220-011-1390-y.

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13

Horan, Barbara L. "Theoretical Models, Biological Complexity and the Semantic View of Theories." PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association 1988, no. 2 (January 1988): 265–77. http://dx.doi.org/10.1086/psaprocbienmeetp.1988.2.192889.

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14

RAST, RICHARD, and DAVENDER SINGH SAHOTA. "THE BOREL COMPLEXITY OF ISOMORPHISM FOR O-MINIMAL THEORIES." Journal of Symbolic Logic 82, no. 2 (June 2017): 453–73. http://dx.doi.org/10.1017/jsl.2017.17.

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AbstractGiven a countable o-minimal theory T, we characterize the Borel complexity of isomorphism for countable models of T up to two model-theoretic invariants. If T admits a nonsimple type, then it is shown to be Borel complete by embedding the isomorphism problem for linear orders into the isomorphism problem for models of T. This is done by constructing models with specific linear orders in the tail of the Archimedean ladder of a suitable nonsimple type.If the theory admits no nonsimple types, then we use Mayer’s characterization of isomorphism for such theories to compute invariants for countable models. If the theory is small, then the invariant is real-valued, and therefore its isomorphism relation is smooth. If not, the invariant corresponds to a countable set of reals, and therefore the isomorphism relation is Borel equivalent to F2.Combining these two results, we conclude that $\left( {{\rm{Mod}}\left( T \right), \cong } \right)$ is either maximally complicated or maximally uncomplicated (subject to completely general model-theoretic lower bounds based on the number of types and the number of countable models).

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15

BOSTELMANN, HENNING, GANDALF LECHNER, and GERARDO MORSELLA. "SCALING LIMITS OF INTEGRABLE QUANTUM FIELD THEORIES." Reviews in Mathematical Physics 23, no. 10 (November 2011): 1115–56. http://dx.doi.org/10.1142/s0129055x11004539.

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Short distance scaling limits of a class of integrable models on two-dimensional Minkowski space are considered in the algebraic framework of quantum field theory. Making use of the wedge-local quantum fields generating these models, it is shown that massless scaling limit theories exist, and decompose into (twisted) tensor products of chiral, translation-dilation covariant field theories. On the subspace which is generated from the vacuum by the observables localized in finite light ray intervals, this symmetry can be extended to the Möbius group. The structure of the interval-localized algebras in the chiral models is discussed in two explicit examples.

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16

De VEGA, H. J. "YANG-BAXTER ALGEBRAS, INTEGRABLE THEORIES AND QUANTUM GROUPS." International Journal of Modern Physics A 04, no. 10 (June 1989): 2371–463. http://dx.doi.org/10.1142/s0217751x89000959.

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The Yang-Baxter-Zamolodchikov-Faddeev (YBZF) algebras and their many applications are the subject of this reivew. I start by the solvable lattice statistical models constructed from YBZF algebras. All two-dimensional integrable vertex models follow in this way and are solvable via Bethe Ansatz (BA) and their generalizations. The six-vertex model solution and its q(2q−1) vertex generalization including its nested BA construction are exposed. YBZF algebras and their associated physical models are classified in terms of simple Lie algebras. It is shown how these lattice models yield both solvable massive quantum field theories (QFT) and conformal models in appropriated scaling (continuous) limits within the lattice light-cone approach. The method of finite-size calculations from the BA is described as well as its applications to derive the conformal properties of integrable lattice models. It is conjectured that all integrable QFT and conformal models follow in a scaling limit from these YBZF algebras. A discussion on braid and quantum groups concludes this review.

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17

Chandrasekharan, S., and U. J. Wiese. "Quantum link models: A discrete approach to gauge theories." Nuclear Physics B 492, no. 1-2 (May 1997): 455–71. http://dx.doi.org/10.1016/s0550-3213(97)80041-7.

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18

Ellwanger, Ulrich. "Supersymmetric σ-models in four dimensions as quantum theories." Nuclear Physics B 281, no. 3-4 (February 1987): 489–508. http://dx.doi.org/10.1016/0550-3213(87)90417-2.

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19

Arovas, Daniel P., and Assa Auerbach. "Functional integral theories of low-dimensional quantum Heisenberg models." Physical Review B 38, no. 1 (July 1, 1988): 316–32. http://dx.doi.org/10.1103/physrevb.38.316.

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20

Hollowood, Timothy J. "Five-dimensional gauge theories and quantum mechanical matrix models." Journal of High Energy Physics 2003, no. 03 (March 24, 2003): 039. http://dx.doi.org/10.1088/1126-6708/2003/03/039.

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21

Alazzawi, Sabina. "Deformations of Fermionic Quantum Field Theories and Integrable Models." Letters in Mathematical Physics 103, no. 1 (June 22, 2012): 37–58. http://dx.doi.org/10.1007/s11005-012-0576-3.

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22

Pynadath, D. V., and M. Tambe. "The Communicative Multiagent Team Decision Problem: Analyzing Teamwork Theories and Models." Journal of Artificial Intelligence Research 16 (June 1, 2002): 389–423. http://dx.doi.org/10.1613/jair.1024.

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Despite the significant progress in multiagent teamwork, existing research does not address the optimality of its prescriptions nor the complexity of the teamwork problem. Without a characterization of the optimality-complexity tradeoffs, it is impossible to determine whether the assumptions and approximations made by a particular theory gain enough efficiency to justify the losses in overall performance. To provide a tool for use by multiagent researchers in evaluating this tradeoff, we present a unified framework, the COMmunicative Multiagent Team Decision Problem (COM-MTDP). The COM-MTDP model combines and extends existing multiagent theories, such as decentralized partially observable Markov decision processes and economic team theory. In addition to their generality of representation, COM-MTDPs also support the analysis of both the optimality of team performance and the computational complexity of the agents' decision problem. In analyzing complexity, we present a breakdown of the computational complexity of constructing optimal teams under various classes of problem domains, along the dimensions of observability and communication cost. In analyzing optimality, we exploit the COM-MTDP's ability to encode existing teamwork theories and models to encode two instantiations of joint intentions theory taken from the literature. Furthermore, the COM-MTDP model provides a basis for the development of novel team coordination algorithms. We derive a domain-independent criterion for optimal communication and provide a comparative analysis of the two joint intentions instantiations with respect to this optimal policy. We have implemented a reusable, domain-independent software package based on COM-MTDPs to analyze teamwork coordination strategies, and we demonstrate its use by encoding and evaluating the two joint intentions strategies within an example domain.

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23

Bhattacharyya, Arpan. "Circuit complexity and (some of) its applications." International Journal of Modern Physics E 30, no. 07 (July 2021): 2130005. http://dx.doi.org/10.1142/s0218301321300058.

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Motivated by recent interesting holographic results, several attempts have been made to study complexity (rather “Circuit Complexity”) for quantum field theories using Nielsen’s geometric method. Since then, it has found many interesting applications. We discuss some of its applications. In particular, we discuss whether circuit complexity can be used as a diagnostics of quantum chaos. We use a simple toy model, namely the Inverted Harmonic Oscillator (IHO), to establish our claim and discuss further applications in the context of quantum cosmology.

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24

Dimitrijevs, Maksims, and Abuzer Yakaryılmaz. "Uncountable classical and quantum complexity classes." RAIRO - Theoretical Informatics and Applications 52, no. 2-3-4 (April 2018): 111–26. http://dx.doi.org/10.1051/ita/2018012.

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It is known that poly-time constant-space quantum Turing machines (QTMs) and logarithmic-space probabilistic Turing machines (PTMs) recognize uncountably many languages with bounded error (A.C. Cem Say and A. Yakaryılmaz, Magic coins are useful for small-space quantum machines. Quant. Inf. Comput. 17 (2017) 1027–1043). In this paper, we investigate more restricted cases for both models to recognize uncountably many languages with bounded error. We show that double logarithmic space is enough for PTMs on unary languages in sweeping reading mode or logarithmic space for one-way head. On unary languages, for quantum models, we obtain middle logarithmic space for counter machines. For binary languages, arbitrary small non-constant space is enough for PTMs even using only counter as memory. For counter machines, when restricted to polynomial time, we can obtain the same result for linear space. For constant-space QTMs, we obtain the result for a restricted sweeping head, known as restarting realtime.

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25

Bahr, Benjamin, Bianca Dittrich, and James P. Ryan. "Spin Foam Models with Finite Groups." Journal of Gravity 2013 (July 24, 2013): 1–28. http://dx.doi.org/10.1155/2013/549824.

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Spin foam models, loop quantum gravity, and group field theory are discussed as quantum gravity candidate theories and usually involve a continuous Lie group. We advocate here to consider quantum gravity-inspired models with finite groups, firstly as a test bed for the full theory and secondly as a class of new lattice theories possibly featuring an analogue diffeomorphism symmetry. To make these notes accessible to readers outside the quantum gravity community, we provide an introduction to some essential concepts in the loop quantum gravity, spin foam, and group field theory approach and point out the many connections to the lattice field theory and the condensed-matter systems.

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26

Krovi, Hari. "Models of optical quantum computing." Nanophotonics 6, no. 3 (March 20, 2017): 531–41. http://dx.doi.org/10.1515/nanoph-2016-0136.

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AbstractI review some work on models of quantum computing, optical implementations of these models, as well as the associated computational power. In particular, we discuss the circuit model and cluster state implementations using quantum optics with various encodings such as dual rail encoding, Gottesman-Kitaev-Preskill encoding, and coherent state encoding. Then we discuss intermediate models of optical computing such as boson sampling and its variants. Finally, we review some recent work in optical implementations of adiabatic quantum computing and analog optical computing. We also provide a brief description of the relevant aspects from complexity theory needed to understand the results surveyed.

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27

Jia, Zhih-Ahn, Lu Wei, Yu-Chun Wu, and Guang-Can Guo. "Quantum Advantages of Communication Complexity from Bell Nonlocality." Entropy 23, no. 6 (June 13, 2021): 744. http://dx.doi.org/10.3390/e23060744.

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Communication games are crucial tools for investigating the limitations of physical theories. The communication complexity (CC) problem is a typical example, for which several distributed parties attempt to jointly calculate a given function with limited classical communications. In this work, we present a method to construct CC problems from Bell tests in a graph-theoretic way. Starting from an experimental compatibility graph and the corresponding Bell test function, a target function that encodes the information of each edge can be constructed; then, using this target function, we can construct a CC function, and by pre-sharing entangled states, its success probability exceeds that of the arbitrary classical strategy. The non-signaling protocol based on the Popescu–Rohrlich box is also discussed, and the success probability in this case reaches one.

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28

FERREIRA, MIGUEL J. B., VICTOR A. PEREIRA, and PAULO TEOTONIO-SOBRINHO. "QUASI-TOPOLOGICAL QUANTUM FIELD THEORIES AND ℤ2 LATTICE GAUGE THEORIES." International Journal of Modern Physics A 27, no. 23 (September 18, 2012): 1250132. http://dx.doi.org/10.1142/s0217751x12501321.

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We consider a two-parameter family of ℤ2 gauge theories on a lattice discretization [Formula: see text] of a three-manifold [Formula: see text] and its relation to topological field theories. Familiar models such as the spin-gauge model are curves on a parameter space Γ. We show that there is a region Γ0 ⊂ Γ where the partition function and the expectation value 〈WR(γ)〉 of the Wilson loop can be exactly computed. Depending on the point of Γ0, the model behaves as topological or quasi-topological. The partition function is, up to a scaling factor, a topological number of [Formula: see text]. The Wilson loop on the other hand, does not depend on the topology of γ. However, for a subset of Γ0, 〈WR(γ)〉 depends on the size of γ and follows a discrete version of an area law. At the zero temperature limit, the spin-gauge model approaches the topological and the quasi-topological regions depending on the sign of the coupling constant.

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29

ALEXANDRE, JEAN. "LIFSHITZ-TYPE QUANTUM FIELD THEORIES IN PARTICLE PHYSICS." International Journal of Modern Physics A 26, no. 26 (October 20, 2011): 4523–41. http://dx.doi.org/10.1142/s0217751x11054656.

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This introduction to Lifshitz-type field theories reviews some of its aspects in Particle Physics. Attractive features of these models are described with different examples, as the improvement of graphs convergence, the introduction of new renormalizable interactions, dynamical mass generation, asymptotic freedom, and other features related to more specific models. On the other hand, problems with the expected emergence of Lorentz symmetry in the IR are discussed, related to the different effective light cones seen by different particles when they interact.

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30

Arovas, Daniel P., and Assa Auerbach. "Erratum: Functional integral theories of low-dimensional quantum Heisenberg models." Physical Review B 40, no. 1 (July 1, 1989): 791. http://dx.doi.org/10.1103/physrevb.40.791.

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31

CHAKRABORTY, SUBENOY. "QUANTUM COSMOLOGY IN ANISOTROPIC COSMOLOGICAL MODELS WITH SCALAR–TENSOR THEORIES." International Journal of Modern Physics D 10, no. 06 (December 2001): 943–56. http://dx.doi.org/10.1142/s0218271801001244.

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This paper deals with quantum cosmological phenomena in anisotropic cosmological models with nonminimally coupled scalor field. With proper transformation of the field variables, the Wheeler–Dewitt (WD) equation looks simple in form and solutions are obtained using separable form of the wave function. Using part integral formulation, the wave function of the Universe has been evaluated by the method of steepest descent. Finally, the causal interpretation has been done using quantum Bohmian trajectories and also we study the classical limit of some particular solutions of these quantum models.

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32

Janiš, V., and D. Vollhardt. "Construction of analytically tractable mean-field theories for quantum models." Zeitschrift für Physik B Condensed Matter 91, no. 3 (September 1993): 317–23. http://dx.doi.org/10.1007/bf01344060.

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Janiš, V., J. Mašek, and D. Vollhardt. "Construction of analytically tractable mean-field theories for quantum models." Zeitschrift für Physik B Condensed Matter 91, no. 3 (September 1993): 325–36. http://dx.doi.org/10.1007/bf01344061.

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34

Ho, Wen Wei, and Đorđe Radičević. "The ergodicity landscape of quantum theories." International Journal of Modern Physics A 33, no. 04 (February 10, 2018): 1830004. http://dx.doi.org/10.1142/s0217751x18300041.

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This paper is a physicist’s review of the major conceptual issues concerning the problem of spectral universality in quantum systems. Here, we present a unified, graph-based view of all archetypical models of such universality (billiards, particles in random media, interacting spin or fermion systems). We find phenomenological relations between the onset of ergodicity (Gaussian-random delocalization of eigenstates) and the structure of the appropriate graphs, and we construct a heuristic picture of summing trajectories on graphs that describes why a generic interacting system should be ergodic. We also provide an operator-based discussion of quantum chaos and propose criteria to distinguish bases that can usefully diagnose ergodicity. The result of this analysis is a rough but systematic outline of how ergodicity changes across the space of all theories with a given Hilbert space dimension. As a particular example, we study the SYK model and report on the transition from maximal to partial ergodicity as the disorder strength is decreased.

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35

Yagi, Junya. "Branes and integrable lattice models." Modern Physics Letters A 32, no. 03 (January 11, 2017): 1730003. http://dx.doi.org/10.1142/s0217732317300038.

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This is a brief review of my work on the correspondence between four-dimensional [Formula: see text] supersymmetric field theories realized by brane tilings and two-dimensional integrable lattice models. I explain how to construct integrable lattice models from extended operators in partially topological quantum field theories, and elucidate the correspondence as an application of this construction.

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36

Cappelli, Andrea, Carlo A. Trugenberger, and Guillermo R. Zemba. "W1+∞ Field Theories for the Edge Extensions in the Quantum Hall Effect." International Journal of Modern Physics A 12, no. 06 (March 10, 1997): 1101–11. http://dx.doi.org/10.1142/s0217751x97000827.

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We briefly review these low-energy effective theories for the quantum Hall effect, with emphasis and language familiar to field theorists. Two models have been proposed for describing the most stable Hall plateaus (the Jain series): the multi-component Abelian theories and the minimal W1+∞ models. They both lead to a-priori classifications of quantum Hall universality classes. Some experiments already confirmed the basic predictions common to both effective theories, while other experiments will soon pin down their detailed properties and differences. Based on the study of partition functions, we show that the Abelian theories are rational conformal field theories while the minimal W1+∞ models are not.

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FILIPPOV, A. T., D. GANGOPADHYAY, and A. P. ISAEV. "QUANTUM DISCRETE GAUGE MODELS WITH BOSONIC AND FERMIONIC DEGREES OF FREEDOM." International Journal of Modern Physics A 07, no. 11 (April 30, 1992): 2487–507. http://dx.doi.org/10.1142/s0217751x92001101.

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A general approach to quantizing discrete models (i.e. having a finite number of coordinates) with quadratic first-class constraints is presented in the framework of gauging linear canonical symmetries. Also, it is proposed how a natural superextension of matrix field theories (viz. orthosymplectic "zero-dimensional" matrix field theories) might emerge in this approach.

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38

Gunitsky, Seva. "Complexity and theories of change in international politics." International Theory 5, no. 1 (March 2013): 35–63. http://dx.doi.org/10.1017/s1752971913000110.

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This article examines how the principles of complex systems can illuminate recurring mechanisms of change in theories of international relations. It applies the logic of complex systems to two specific puzzles in international politics – the problem of theorizing change in structural realism, and the dynamics of cross-border democratic diffusion. In the first case, by shifting the analysis of anarchy's consequences from state behavior to state attributes, complex systems can illustrate the sources of domestic and international transformations embedded in structural theories. This approach offers a way to think about democratization as a global process of interstate competition and socialization driven by the pressures of anarchy. In the second case, the principles of co-adaptation in complex systems can help reframe diffusion not as the unilinear spread of democracy but as the interplay of self-reinforcing and self-dampening dynamics, whose interaction shapes both actor expectations and democratic outcomes. In both cases, complex systems serve a limited but useful role; although not conducive to theory creation, the approach provides a useful analytical prism for examining patterns of change and continuity in global processes, and highlights concrete ways of improving models of transformations in international politics.

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Momani, Alaa M., Mamoun M. Jamous, and Shadi M. S. Hilles. "Technology Acceptance Theories." International Journal of Cyber Behavior, Psychology and Learning 7, no. 2 (April 2017): 1–14. http://dx.doi.org/10.4018/ijcbpl.2017040101.

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Studying the acceptance and usage of technologies has become one of the most significant fields in software engineering domain. In order to explain the individuals' usage behavior towards technologies, many theories and models have been proposed over the years. This research paper focuses on reviewing a group of ten technology acceptance theories and models by studying their structure, evolution stages, and their strengths and weaknesses points. These theories were analyzed and classified into two main types depending on their development method and scientific field which they were developed in. This study reveals that these theories are almost similar in their structure, but different in explaining the behavioral intentions of technology. It considers that the best theory should be comprehensive and less complexity according to the number of the constructs and moderators which represent their structure. This will make the theory more understandable and applicable especially for studying the acceptance behavior for any new technology.

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Esipova, S. R., P. M. Lavrov, and O. V. Radchenko. "Supersymmetric invariant theories." International Journal of Modern Physics A 29, no. 11n12 (April 25, 2014): 1450065. http://dx.doi.org/10.1142/s0217751x14500651.

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We study field models for which a quantum action (i.e. the action appearing in the generating functional of Green functions) is invariant under supersymmetric transformations. We derive the Ward identity which is a direct consequence of this invariance. We consider a change of variables in functional integral connected with supersymmetric transformations when its parameter is replaced by a nilpotent functional of fields. Exact form of the corresponding Jacobian is found. We find restrictions on generators of supersymmetric transformations when a consistent quantum description of given field theories exists.

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SIOPSIS, GEORGE. "ON THE QUANTUM GROUP STRUCTURE IN WZW MODELS AND CHERN–SIMONS THEORIES." Modern Physics Letters A 06, no. 16 (May 30, 1991): 1515–23. http://dx.doi.org/10.1142/s0217732391001627.

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We discuss the origin of quantum group features in both Wess–Zumino–Witten models and (2 + 1)-dimensional topological Chern–Simons theories. We identify certain matrices in these theories whose elements obey commutation relations characteristic of a quantum group.

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Syros, C. "New developments in Time-Asymmetry of Quantum Field Theories." HNPS Proceedings 9 (February 11, 2020): 357. http://dx.doi.org/10.12681/hnps.2797.

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Time-asymmetric evolution is derived from time-reversal invariant fundamental QFT-equations. Chrono-topology, the disconnected time topological space J4, is the playground for the generalized random and infinitely divisable quantum fields, a new development in time-asymmetry. Based on the properties of this time space and using the theory of random quantum fields previously developed a non-unitary, complexity evolution operator, C(J4), is derived. C(J4) breaks down, by Bohr- quantizing the field-action integral, alternatively into two, spontaneously renormal- ized parts: One, (unitary) Uu(r), implying U - processes and one (non-measure- preserving), Knmp(r), producing R - processes. Unmp(r), breaks time-symmetry and provides a basis for CP-violation in QFT and in particular in the K0-meson decay. Functional integrals arising in the theory have as a limit Feynman's path integral in accordance with the measure theoretical requirements. Irreversibility and time-symmetry are not incompatible (compare Boltzmann, Poincaré) in chrono-topology.

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Moshin, Pavel Yu, and Alexander A. Reshetnyak. "Composite and Background Fields in Non-Abelian Gauge Models." Symmetry 12, no. 12 (November 30, 2020): 1985. http://dx.doi.org/10.3390/sym12121985.

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A joint introduction of composite and background fields into non-Abelian quantum gauge theories is suggested based on the symmetries of the generating functional of Green’s functions, with the systematic analysis focused on quantum Yang–Mills theories, including the properties of the generating functional of vertex Green’s functions (effective action). For the effective action in such theories, gauge dependence is found in terms of a nilpotent operator with composite and background fields, and on-shell independence from gauge fixing is established. The basic concept of a joint introduction of composite and background fields into non-Abelian gauge theories is extended to the Volovich–Katanaev model of two-dimensional gravity with dynamical torsion, as well as to the Gribov–Zwanziger theory.

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Holik, Federico, César Massri, Angelo Plastino, and Manuel Sáenz. "Generalized Probabilities in Statistical Theories." Quantum Reports 3, no. 3 (July 29, 2021): 389–416. http://dx.doi.org/10.3390/quantum3030025.

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We discuss different formal frameworks for the description of generalized probabilities in statistical theories. We analyze the particular cases of probabilities appearing in classical and quantum mechanics and the approach to generalized probabilities based on convex sets. We argue for considering quantum probabilities as the natural probabilistic assignments for rational agents dealing with contextual probabilistic models. In this way, the formal structure of quantum probabilities as a non-Boolean probabilistic calculus is endowed with a natural interpretation.

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Grigoryan, G. V., R. P. Grigoryan, and I. V. Tyutin. "Comparison of O- and C-models on pseudosphere." International Journal of Modern Physics A 31, no. 34 (December 6, 2016): 1650179. http://dx.doi.org/10.1142/s0217751x16501797.

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We present a mathematically rigorous quantum-mechanical treatment of a two-dimensional nonrelativistic quantum dual theories (with oscillator- and Coulomb-like potentials) on pseudosphere. We construct all self-adjoint Schrödinger operators for these theories and present solutions of the corresponding spectral problems. We show, that there is one-to-one correspondence between spectral points of the energy-coupling constant planes not only for discrete, but also for continuous spectra and corresponding eigenfunctions forming the complete orthonormalized systems.

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GRANDITS, PETER. "ON NON-SUPERSYMMETRIC FINITE QUANTUM FIELD THEORIES." International Journal of Modern Physics A 10, no. 10 (April 20, 1995): 1507–28. http://dx.doi.org/10.1142/s0217751x95000723.

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In a previous paper, requiring finiteness of Yukawa couplings in one-loop approximation, a no-go theorem for the finiteness of non-supersymmetric gauge theories with gauge group SU (n) was proven. Interestingly enough the gauge group SU(5), prominent in GUT models, was not covered by this proof. However, with somewhat more effort the no-go theorem can be extended to this case. Considering an even larger class of particle contents, we show that the number of possibly finite theories is greatly reduced. It should be stressed that our results are based upon two-loop finiteness of the gauge coupling, although in order to find really finite theories the finiteness conditions on the quartic scalar couplings have to be considered too.

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FEWSTER, CHRISTOPHER J., and STEFAN HOLLANDS. "QUANTUM ENERGY INEQUALITIES IN TWO-DIMENSIONAL CONFORMAL FIELD THEORY." Reviews in Mathematical Physics 17, no. 05 (June 2005): 577–612. http://dx.doi.org/10.1142/s0129055x05002406.

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Quantum energy inequalities (QEIs) are state-independent lower bounds on weighted averages of the stress-energy tensor, and have been established for several free quantum field models. We present rigorous QEI bounds for a class of interacting quantum fields, namely the unitary, positive energy conformal field theories (with stress-energy tensor) on two-dimensional Minkowski space. The QEI bound depends on the weight used to average the stress-energy tensor and the central charge(s) of the theory, but not on the quantum state. We give bounds for various situations: averaging along timelike, null and spacelike curves, as well as over a space-time volume. In addition, we consider boundary conformal field theories and more general "moving mirror" models. Our results hold for all theories obeying a minimal set of axioms which — as we show — are satisfied by all models built from unitary highest-weight representations of the Virasoro algebra. In particular, this includes all (unitary, positive energy) minimal models and rational conformal field theories. Our discussion of this issue collects together (and, in places, corrects) various results from the literature which do not appear to have been assembled in this form elsewhere.

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Figueroa-O'Farrill, José M., and Sonia Stanciu. "Supersymmetric Cosets from Gauged SWZW Models." Modern Physics Letters A 12, no. 23 (July 30, 1997): 1677–85. http://dx.doi.org/10.1142/s0217732397001710.

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In this letter, which complements and extends our work7 on the superconformal field theories obtained from SWZW models based on general self-dual Lie algebras, we prove the quantum equivalence of the two known descriptions of the gauged supersymmetric WZW model, and as a corollary we show that in the case of the topological G/G gauging, the supersymmetric and nonsupersymmetric theories agree.

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Aravinda, S., Anindita Banerjee, Anirban Pathak, and R. Srikanth. "Orthogonal-state-based cryptography in quantum mechanics and local post-quantum theories." International Journal of Quantum Information 12, no. 07n08 (November 2014): 1560020. http://dx.doi.org/10.1142/s0219749915600205.

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We introduce the concept of cryptographic reduction, in analogy with a similar concept in computational complexity theory. In this framework, class A of crypto-protocols reduces to protocol class B in a scenario X, if for every instance a of A, there is an instance b of B and a secure transformation X that reproduces a given b, such that the security of b guarantees the security of a. Here we employ this reductive framework to study the relationship between security in quantum key distribution (QKD) and quantum secure direct communication (QSDC). We show that replacing the streaming of independent qubits in a QKD scheme by block encoding and transmission (permuting the order of particles block by block) of qubits, we can construct a QSDC scheme. This forms the basis for the block reduction from a QSDC class of protocols to a QKD class of protocols, whereby if the latter is secure, then so is the former. Conversely, given a secure QSDC protocol, we can of course construct a secure QKD scheme by transmitting a random key as the direct message. Then the QKD class of protocols is secure, assuming the security of the QSDC class which it is built from. We refer to this method of deduction of security for this class of QKD protocols, as key reduction. Finally, we propose an orthogonal-state-based deterministic key distribution (KD) protocol which is secure in some local post-quantum theories. Its security arises neither from geographic splitting of a code state nor from Heisenberg uncertainty, but from post-measurement disturbance.

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Delcamp, Clement, and Bianca Dittrich. "From 3D topological quantum field theories to 4D models with defects." Journal of Mathematical Physics 58, no. 6 (June 2017): 062302. http://dx.doi.org/10.1063/1.4989535.

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