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César Massri

Publications and source records attributed to César Massri.

At least 19 recordsLinked to original sources

Deformations of exterior differential ideals and applications

We develop some basic facts on deformations of exterior differential ideals on a smooth complex algebraic variety. With these tools we study deformations of several types of differential ideals, leading to several irreducible components of the corresponding moduli spaces

math.AG↗

Multi-Screen Entanglement in Tensorial Quantum Mechanics

In this work we present an invariant-objective formalization of multi screen-entanglement grounded on Tensorial Quantum Mechanics (TQM) [12]. This new tensorial formulation of the theory of quanta -- basically, an extension of Heisenberg's matrix mechanics -- allows not only to escape the many problems present in the current account of multi-partite entanglement grounded on the Dirac-Von Neumann Standard formulation of Quantum Mechanics (SQM) but, more importantly, to consistently represent entanglement phenomena when considering a multiplicity of different screens and detectors.

quant-ph↗

The Many Inconsistencies of the Purity-Mixture Distinction in Standard Quantum Mechanics

The distinction between pure states and mixed states is a kernel ingredient of what is considered to be the standard formulation of quantum mechanics and plays today a kernel role in foundational debates about the meaning of quantum probability, the separability of quantum systems, the definition and measure of entanglement, etc. In this work we attempt to expose the many inconsistencies introduced by this distinction and the serious consequences this has for many ongoing research programs within quantum physics which apply these notions uncritically.

physics.hist-ph↗

Tensorial Quantum Mechanics: Back to Heisenberg and Beyond

In this work we discuss the establishment of Standard Quantum Mechanics (SQM) developed through Schrödinger's and Dirac's wave-vectorial reformulations of Heisenberg's original matrix mechanics. We will argue that while Heisenberg's approach was consistently developed -- taking as a standpoint the intensive patterns that were observed in the lab -- as an invariant-operational formalism, Dirac's axiomatic re-formulation was, instead, developed -- taking as a standpoint Schrödinger's wave mechanics and the methodological guide of Bohr and logical positivists -- as an essentially inconsistent "recipe" intended (but unable) to predict (binary) measurement outcomes. Leaving SQM behind and attempting to restore the consistent and coherent account of a real state of affairs, we will present a new tensorial proposal which -- taking as a standpoint Heisenberg's original approach -- will prove capable not only to extend the matrix formalism to a tensorial representation but also to account for new experimental phenomena.

quant-ph↗

On the Relative Nature of Quantum Individuals

In this work we argue against the interpretation that underlies the "Standard" account of Quantum Mechanics (SQM) that was established during the 1930s by Niels Bohr and Paul Dirac. Ever since, following this orthodox narrative, physicists have dogmatically proclaimed -- quite regardless of the deep contradictions and problems -- that the the theory of quanta describes a microscopic realm composed of elementary particles (such as electrons, protons and neutrons) which underly our macroscopic world composed of tables, chairs and dogs. After critically addressing this atomist dogma still present today in contemporary (quantum) physics and philosophy, we present a new understanding of quantum individuals defined as the minimum set of relations within a specific degree of complexity capable to account for all relations within that same degree. In this case, quantum individuality is not conceived in absolute terms but -- instead -- as an objectively relative concept which even though depends of the choice of bases and factorizations remain nonetheless part of the same invariant representation.

physics.gen-ph↗

Lower Bounds for the Minimum Spanning Tree Cycle Intersection Problem

Minimum spanning trees are important tools in the analysis and design of networks. Many practical applications require their computation, ranging from biology and linguistics to economy and telecommunications. The set of cycles of a network has a vector space structure. Given a spanning tree, the set of non-tree edges defines cycles that determine a basis. The intersection of two such cycles is the number of edges they have in common and the intersection number -- denoted $\cap(G)$ -- is the number of non-empty pairwise intersections of the cycles of the basis. The Minimum Spanning Tree Cycle Intersection problem consists in finding a spanning tree such that the intersection number is minimum. This problem is relevant in order to integrate discrete differential forms. In this paper, we present two lower bounds of the intersection number of an arbitrary connected graph $G=(V,E)$. In the first part, we prove the following statement: $$\frac{1}{2}\left(\frac{ν^2}{n-1} - ν\right) \leq \cap(G),$$ where $n = |V|$ and $ν$ is the \emph{cyclomatic number} of $G$. In the second part, based on some experimental results and a new observation, we conjecture the following improved tight lower bound: $$(n-1) \binom{q}{2} + q \ r\leq \cap(G),$$ where $2 ν= q (n-1) + r$ is the integer division of $2 ν$ and $n-1$. This is the first result in a general context, that is for an arbitrary connected graph.

cs.DM↗

Three aspects of the MSTCI problem

Consider a connected graph $G$ and let $T$ be a spanning tree of $G$. Every edge $e \in G-T$ induces a cycle in $T \cup \{e\}$. The intersection of two distinct such cycles is the set of edges of $T$ that belong to both cycles. The MSTCI problem consists in finding a spanning tree that has the least number of such non-empty intersections and the instersection number is the number of non-empty intersections of a solution. In this article we consider three aspects of the problem in a general context (i.e. for arbitrary connected graphs). The first presents two lower bounds of the intersection number. The second compares the intersection number of graphs that differ in one edge. The last is an attempt to generalize a recent result for graphs with a universal vertex.

math.CO↗

Minimum Spanning Tree Cycle Intersection Problem

Consider a connected graph $G$ and let $T$ be a spanning tree of $G$. Every edge $e \in G-T$ induces a cycle in $T \cup \{e\}$. The intersection of two distinct such cycles is the set of edges of $T$ that belong to both cycles. We consider the problem of finding a spanning tree that has the least number of such non-empty intersections.

cs.DM↗

tinygarden -- A java package for testing properties of spanning trees

Spanning trees are fundamental objects in graph theory. The spanning tree set size of an arbitrary graph can be very large. This limitation discourages its analysis. However interesting patterns can emerge in small cases. In this article we introduce \emph{tinygarden}, a java package for validating hypothesis, testing properties and discovering patterns from the spanning tree set of an arbitrary graph.

cs.DM↗

Measure-theoretic approach to negative probabilities

In this work, we elaborate on a measure-theoretic approach to negative probabilities. We study a natural notion of contextuality measure and characterize its main properties. Then, we apply this measure to relevant examples of quantum physics. In particular, we study the role played by contextuality in quantum computing circuits.

quant-ph↗

Against the Tyranny of Pure States in Quantum Theory

We argue that the notion of pure sate within Standard Quantum Mechanics is presently applied within the specialized literature in relation to two mutually inconsistent definitions. While the first (operational purity) provides a basis-dependent definition which makes reference to the certain prediction of measurement outcomes, the latter (trace-invariant purity) provides a purely abstract invariant definition which lacks operational content. In this work we derive a theorem which exposes the serious inconsistencies existent within these two incompatible definitions of purity.

quant-ph↗

Relational Quantum Entanglement Beyond Non-Separable and Contextual Relativism

In this paper we address the relativist-perspectival nature of the orthodox definition of quantum entanglement in terms of preferred factorizations. We also consider this aspect aspect within the generalized definition of entanglement proposed by Barnum et al. [6, 7] in terms of preferred observables. More specifically, we will discuss the non-separable relativism implied by the orthodox definition of entanglement, the contextual relativism implied by its generalization as well as some other serious problems presently discussed within the specialized literature. In the second part of this work, we address a recently proposed objective-invariant definition of entanglement understood as the actual and potential coding of effective and intensive relations [32]. Through the derivation of two theorems we will show explicitly how this new objective definition of entanglement is able to escape both non-separable relativism and contextual relativism. According to these theorems, within this proposed relational definition, all possible subsets of observables as well as all possible factorizations can be globally considered as making reference to the same (potential) state of affairs. The conclusion is that, unlike with the orthodox definitions, this new objective-relational notion of entanglement is able to bypass relativism right from the start opening the door to a realist understanding of quantum correlations.

quant-ph↗

Beyond Purity and Mixtures in Categorical Quantum Mechanics

In a recent paper [12], we discussed the serious inconsistency present within the operational and mathematical definition(s) of the notion of pure state. Continuing this analysis, in this work we attempt to address the role of 'purity' and 'mixtures' within two different categorical approaches to QM, namely, the topos approach originally presented by Chris Isham and Jeremy Butterfield [27, 28, 29] and the more recent logos categorical approach presented by the authors of this article [10, 11, 13]. While the first approach exposes the difficulties to produce a consistent understanding of pure states and mixtures, the latter approach presents a new scheme in which their reference is erased right from the start in favor of an intensive understanding of projection operators and quantum superpositions. This new account of the theory, grounded on an intensive interpretation of the Born rule, allows us not only to avoid the orthodox interpretation of projection operators --either as referring to definite valued properties or measurement outcomes-- but also to consider all matrices (of any rank) on equal footing. It is from this latter standpoint that we conclude that instead of distinguishing between pure and mixed states it would be recommendable --for a proper understanding of the theory of quanta-- to return to the original matrix formulation of quantum mechanics presented by Werner Heisenberg in 1925.

quant-ph↗

Extremal elements of a sublattice of the majorization lattice and approximate majorization

Given a probability vector $x$ with its components sorted in non-increasing order, we consider the closed ball ${\mathcal{B}}^p_ε(x)$ with $p \geq 1$ formed by the probability vectors whose $\ell^p$-norm distance to the center $x$ is less than or equal to a radius $ε$. Here, we provide an order-theoretic characterization of these balls by using the majorization partial order. Unlike the case $p=1$ previously discussed in the literature, we find that the extremal probability vectors, in general, do not exist for the closed balls ${\mathcal{B}}^p_ε(x)$ with $1<p<\infty$. On the other hand, we show that ${\mathcal{B}}^\infty_ε(x)$ is a complete sublattice of the majorization lattice. As a consequence, this ball has also extremal elements. In addition, we give an explicit characterization of those extremal elements in terms of the radius and the center of the ball. This allows us to introduce some notions of approximate majorization and discuss its relation with previous results of approximate majorization given in terms of the $\ell^1$-norm. Finally, we apply our results to the problem of approximate conversion of resources within the framework of quantum resource theory of nonuniformity.

quant-ph↗

Against 'Particle Metaphysics' and 'Collapses' within the Definition of Quantum Entanglement

In this paper we argue against the orthodox definition of quantum entanglement which has been explicitly grounded on several "common sense" (metaphysical) presuppositions and presents today serious formal and conceptual drawbacks. This interpretation which some researchers in the field call "minimal", has ended up creating a narrative according to which QM talks about "small particles" represented by pure states (in general, superpositions) which --each time someone attempts to observe what is going on-- suddenly "collapse" to a single measurement outcome. After discussing the consequences of applying 'particle metaphysics' within the definition of entanglement we turn our attention to two recent approaches which might offer an interesting way out of this metaphysical conundrum. Both approaches concentrate their efforts in going beyond the notion of 'system'. While the first, called device-independent approach, proposes an operational anti-metaphysical scheme in which language plays an essential role; the second approach, takes an essentially metaphysical path which attempts to present a new non-classical representation grounded on intensive relations which, in turn, imposes the need to reconsider the definition and meaning of quantum entanglement.

quant-ph↗

A New Objective Definition of Quantum Entanglement as Potential Coding of Intensive and Effective Relations

In [20] it was argued against the orthodox definition of quantum entanglement in terms of pure and separable states. In this paper we attempt to discuss how the logos categorical approach to quantum mechanics [18, 19] is able to provide an objective formal account of the notion of entanglement --completely independent of both purity and separability-- in terms of the potential coding of intensive relations and effective relations. We will show how our novel redefinition allows us to provide an anschaulich content to the notion of entanglement, erasing in this way the "spookiness" still present within its orthodox understanding in terms of space-time separated collapse particles.

quant-ph↗

Taking Mermin's Relational Interpretation of QM Beyond Cabello's and Seevinck's No-Go Theorems

In this paper we address a deeply interesting debate that took place at the end of the last millennia between David Mermin, Adan Cabello and Michiel Seevinck, regarding the meaning of relationalism within quantum theory. In a series of papers, Mermin proposed an interpretation in which quantum correlations were considered as elements of physical reality. Unfortunately, the very young relational proposal by Mermin was too soon tackled by specially suited no-go theorems designed by Cabello and Seevinck. In this work we attempt to reconsider Mermin's program from the viewpoint of the Logos Categorical Approach to QM. Following Mermin's original proposal, we will provide a redefinition of quantum relation which not only can be understood as a preexistent element of physical reality but is also capable to escape Cabello's and Seevinck's no-go-theorems. In order to show explicitly that our notion of ontological quantum relation is safe from no-go theorems we will derive a non-contextuality theorem. We end the paper with a discussion regarding the physical meaning of quantum relationalism.

physics.hist-ph↗

Against Collapses, Purity and Separability Within the Definition of Quantum Entanglement

In this paper we we will argue against the orthodox definition of quantum entanglement which has been implicitly grounded on several widespread (metaphysical) presuppositions which have no relation whatsoever to the formalism of QM. We will show how these presuppositions have been introduced through a naive interpretation of the quantum mathematical structure which assumes dogmatically that the theory talks about "small particles" represented by pure states (in general, superpositions) which suddenly "collapse" when a measurement takes place. In the second part of this paper we will present a non-collapse approach to QM which makes no use whatsoever of particle metaphysics, escaping the need to make reference to space-time separability or the restriction to certain predictions of definite valued binary properties. Our paper ends up concluding the essential need to redefine the notion of quantum entanglement, at least in the cases of: i) non-collapse interpretations of QM; or, ii) any other interpretation which abandons the idea that QM makes reference to "small particles".

quant-ph↗