Graph data models are widely used in many areas, for example, bioinformatics, graph databases. In... more Graph data models are widely used in many areas, for example, bioinformatics, graph databases. In these areas, it is often required to process queries for large graphs. Some of the most common graph queries are navigational queries. The result of query evaluation is a set of implicit relations between nodes of the graph, i.e. paths in the graph. A natural way to specify these relations is by specifying paths using formal grammars over the alphabet of edge labels. An answer to a context-free path query in this approach is usually a set of triples (A, m, n) such that there is a path from the node m to the node n, whose labeling is derived from a non-terminal A of the given context-free grammar. This type of queries is evaluated using the relational query semantics. Another example of path query semantics is the single-path query semantics which requires presenting a single path from the node m to the node n, whose labeling is derived from a non-terminal A for all triples (A, m, n) evaluated using the relational query semantics. There is a number of algorithms for query evaluation which use these semantics but all of them perform poorly on large graphs. One of the most common technique for efficient big data processing is the use of a graphics processing unit (GPU) to perform computations, but these algorithms do not allow to use this technique efficiently. In this paper, we show how the context-free path query evaluation using these query semantics can be reduced to the calculation of the matrix transitive closure. Also, we propose an algorithm for context-free path query evaluation which uses relational query semantics and is based on matrix operations that make it possible to speed up computations by using a GPU.
We consider the lepton-flavor violating (LFV) lepton-quark dimension-6 operators and analyze thei... more We consider the lepton-flavor violating (LFV) lepton-quark dimension-6 operators and analyze their contributions to the LFV leptonic decays of vector, pseudoscalar, and scalar neutral mesons M→ℓ_1 ℓ_2 as well as to μ(τ) →ℓ ee, ℓγγ decays. These operators contribute to the purely leptonic processes via quark loop. On the basis of quark-hadron duality, we relate these loops to the appropriate meson-exchange contributions. In this way, we extract lower bounds on the individual scales of the studied LFV operators from the experimental and phenomenological limits on the leptonic decays of mesons and leptons. As a byproduct, we shall obtain new limits on the LFV leptonic decays of flavored mesons from the experimental bounds on the three-body lepton decays. We study the effects of QED and QCD radiative corrections to the LFV lepton-quark operators in question. We derive for them the one-loop matrix of the RGE evolution and examine its effect on the previously derived tree-level limits on ...
We construct a viable extension of the SM with a heavy vector in the fundamental SU( 2) _L repres... more We construct a viable extension of the SM with a heavy vector in the fundamental SU( 2) _L representation and nine SM singlet scalar fields, consistent with the current SM fermion mass spectrum and fermionic mixing parameters. The small masses for the active neutrinos are generated from radiative seesaw mechanism at one loop level mediated by the neutral components of the heavy vector as well as by the left handed Majorana neutrinos. We carry out an analysis of the predictions in the lepton sector, where the model is only viable in the scenario of inverted neutrino mass ordering.
Mostramos el campo de Dirac para una partícula masiva libre que describe el movimiento de un ferm... more Mostramos el campo de Dirac para una partícula masiva libre que describe el movimiento de un fermión relativístico, usando el formalismo de la teoría cuántica de campos. Introducimos una sustitución no-mínima en el operador de momentum, el cual nos produce el oscilador de Dirac, entonces procedemos a cuantizarlo canónicamente y expresamos el operador del campo del oscilador de Dirac en función de los operadores de creación y aniquilación.
We consider the lepton-flavor violating (LFV) lepton-quark dimension-6 operators and analyze thei... more We consider the lepton-flavor violating (LFV) lepton-quark dimension-6 operators and analyze their contributions to the LFV leptonic decays of vector, pseudoscalar, and scalar neutral mesons M → `1`2 as well as to μ(τ) → `ee, `γγ decays. These operators contribute to the purely leptonic processes via quark loop. On the basis of quark-hadron duality, we relate these loops to the appropriate meson-exchange contributions. In this way, we extract lower bounds on the individual scales of the studied LFV operators from the experimental and phenomenological limits on the leptonic decays of mesons and leptons. As a byproduct, we shall obtain new limits on the LFV leptonic decays of flavored mesons from the experimental bounds on the three-body lepton decays. We study the effects of QED and QCD radiative corrections to the LFV lepton-quark operators in question. We derive for them the one-loop matrix of the RGE evolution and examine its effect on the previously derived tree-level limits on t...
Graph data models are widely used in many areas, for example, bioinformatics, graph databases. In... more Graph data models are widely used in many areas, for example, bioinformatics, graph databases. In these areas, it is often required to process queries for large graphs. Some of the most common graph queries are navigational queries. The result of query evaluation is a set of implicit relations between nodes of the graph, i.e. paths in the graph. A natural way to specify these relations is by specifying paths using formal grammars over the alphabet of edge labels. An answer to a context-free path query in this approach is usually a set of triples (A, m, n) such that there is a path from the node m to the node n, whose labeling is derived from a non-terminal A of the given context-free grammar. This type of queries is evaluated using the relational query semantics. Another example of path query semantics is the single-path query semantics which requires presenting a single path from the node m to the node n, whose labeling is derived from a non-terminal A for all triples (A, m, n) evaluated using the relational query semantics. There is a number of algorithms for query evaluation which use these semantics but all of them perform poorly on large graphs. One of the most common technique for efficient big data processing is the use of a graphics processing unit (GPU) to perform computations, but these algorithms do not allow to use this technique efficiently. In this paper, we show how the context-free path query evaluation using these query semantics can be reduced to the calculation of the matrix transitive closure. Also, we propose an algorithm for context-free path query evaluation which uses relational query semantics and is based on matrix operations that make it possible to speed up computations by using a GPU.
We consider the lepton-flavor violating (LFV) lepton-quark dimension-6 operators and analyze thei... more We consider the lepton-flavor violating (LFV) lepton-quark dimension-6 operators and analyze their contributions to the LFV leptonic decays of vector, pseudoscalar, and scalar neutral mesons M→ℓ_1 ℓ_2 as well as to μ(τ) →ℓ ee, ℓγγ decays. These operators contribute to the purely leptonic processes via quark loop. On the basis of quark-hadron duality, we relate these loops to the appropriate meson-exchange contributions. In this way, we extract lower bounds on the individual scales of the studied LFV operators from the experimental and phenomenological limits on the leptonic decays of mesons and leptons. As a byproduct, we shall obtain new limits on the LFV leptonic decays of flavored mesons from the experimental bounds on the three-body lepton decays. We study the effects of QED and QCD radiative corrections to the LFV lepton-quark operators in question. We derive for them the one-loop matrix of the RGE evolution and examine its effect on the previously derived tree-level limits on ...
We construct a viable extension of the SM with a heavy vector in the fundamental SU( 2) _L repres... more We construct a viable extension of the SM with a heavy vector in the fundamental SU( 2) _L representation and nine SM singlet scalar fields, consistent with the current SM fermion mass spectrum and fermionic mixing parameters. The small masses for the active neutrinos are generated from radiative seesaw mechanism at one loop level mediated by the neutral components of the heavy vector as well as by the left handed Majorana neutrinos. We carry out an analysis of the predictions in the lepton sector, where the model is only viable in the scenario of inverted neutrino mass ordering.
Mostramos el campo de Dirac para una partícula masiva libre que describe el movimiento de un ferm... more Mostramos el campo de Dirac para una partícula masiva libre que describe el movimiento de un fermión relativístico, usando el formalismo de la teoría cuántica de campos. Introducimos una sustitución no-mínima en el operador de momentum, el cual nos produce el oscilador de Dirac, entonces procedemos a cuantizarlo canónicamente y expresamos el operador del campo del oscilador de Dirac en función de los operadores de creación y aniquilación.
We consider the lepton-flavor violating (LFV) lepton-quark dimension-6 operators and analyze thei... more We consider the lepton-flavor violating (LFV) lepton-quark dimension-6 operators and analyze their contributions to the LFV leptonic decays of vector, pseudoscalar, and scalar neutral mesons M → `1`2 as well as to μ(τ) → `ee, `γγ decays. These operators contribute to the purely leptonic processes via quark loop. On the basis of quark-hadron duality, we relate these loops to the appropriate meson-exchange contributions. In this way, we extract lower bounds on the individual scales of the studied LFV operators from the experimental and phenomenological limits on the leptonic decays of mesons and leptons. As a byproduct, we shall obtain new limits on the LFV leptonic decays of flavored mesons from the experimental bounds on the three-body lepton decays. We study the effects of QED and QCD radiative corrections to the LFV lepton-quark operators in question. We derive for them the one-loop matrix of the RGE evolution and examine its effect on the previously derived tree-level limits on t...
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Papers by Jonatan Vignatti