Logic is Metaphysics

Analyzing the position of two philosophers whose views are recognizably divergent, W. O. Quine and M. Dummett, we intend to support a striking point of agreement between them: the idea that our logical principles constitute our principles about what there is, and therefore, that logic is metaphysics

On Quine's Ontology: quantification, extensionality and naturalism (or from commitment to indifference)

Much of the ontology made in the analytic tradition of philosophy nowadays is founded on some of Quine’s proposals. His naturalism and the binding between existence and quantification are respectively two of his very influential metaphilosophical and methodological theses. Nevertheless, many of his specific claims are quite controversial and contemporaneously have few followers. Some of them are: (a) his rejection of higher-order logic; (b) his resistance in accepting the intensionality of ontological commitments; (c) his rejection of first-order modal logic; and (d) his rejection of the distinction between analytic and synthetic statements. I intend to argue that these controversial negative claims are just interconnected consequences of those much more accepted and apparently less harmful metaphilosophical and methodological theses, and that the glue linking all these consequences to its causes is the notion of extensionality

The Evolution of the Retail Trade sector in Iberian Cities from the Nineteenth Century to the Second World War.

This is an Accepted Manuscript version of an article published by Taylor & Francis on 16 May 2017, available online at: http://dx.doi.org/10.1080/2373518X.2017.1329195.The evolution of retail trade in European cities during the first decades of the twentieth century can be a powerful indicator about their urban and social dynamics. The growth in the number of shops, the spatial rearrangement of their distribution, and the increased social and political relevance of shopkeepers are features commonly highlighted by the historiography. But this picture is better known for Central and Northern European cities. As for the Iberian Peninsula although some efforts can be mentioned, there are still progress to be made. The papers discussed in this introductory essay address those questions through a double perspective: first, an analysis of the urban space and its impact on the development of the retail trade's spatial distribution and evolution; second, a historical and comparative analysis of four Iberian cities trying to build a better picture about the spatial, social and economic relevance of their retail trade. These perspectives will be explored for the cities of La Coruña, Barcelona, Bilbao and Lisbon studying the retail trade spatial distribution and the introduction of new forms of commercial concentration and consumption, roughly between 1840 and 1940Peer reviewe

Evolution of complexity following a quantum quench in free field theory

Using a recent proposal of circuit complexity in quantum field theories introduced by Jefferson and Myers, we compute the time evolution of the complexity following a smooth mass quench characterized by a time scale $\delta t$ in a free scalar field theory. We show that the dynamics has two distinct phases, namely an early regime of approximately linear evolution followed by a saturation phase characterized by oscillations around a mean value. The behavior is similar to previous conjectures for the complexity growth in chaotic and holographic systems, although here we have found that the complexity may grow or decrease depending on whether the quench increases or decreases the mass, and also that the time scale for saturation of the complexity is of order $\delta t$ (not parametrically larger).Comment: V2: added references, new plots, and improved discussion of results on Section 5, V3: Few minor corrections. Published versio

Machine learning, quantum chaos, and pseudorandom evolution

By modeling quantum chaotic dynamics with ensembles of random operators, we explore howmachine learning learning algorithms can be used to detect pseudorandom behavior in qubit systems.We analyze samples consisting of pieces of correlation functions and find that machine learningalgorithms are capable of determining the degree of pseudorandomness which a system is subjectto in a precise sense. This is done without computing any correlators explicitly. Interestingly,even samples drawn from two-point functions are found to be sufficient to solve this classificationproblem. This presents the possibility of using deep learning algorithms to explore late time behaviorin chaotic quantum systems which have been inaccessible to simulation.Comment: 8 pages, 3 figure

Amplification of the Signal-to-Noise Ratio in Cosmic Ray Maps Using the Mexican Hat Wavelet Family

In this work we analyze the effect of smoothing maps containing arrival directions of cosmic rays with a gaussian kernel and kernels of the mexican hat wavelets of orders 1, 2 and 3. The analysis is performed by calculating the amplification of the signal-to-noise ratio for several background patterns (noise) and different number of events coming from a simulated source (signal) for an ideal detector capable of observing the full sky with uniform coverage. We extend this analysis for a virtual observatory with two sites, one in the northern hemisphere, the other in the southern, considering an acceptance law.Comment: Contributions to the 32nd International Cosmic Ray Conference, Beijing, China, August 201

A simple agent-based spatial model of the economy: tools for policy

This study simulates the evolution of artificial economies in order to understand the tax relevance of administrative boundaries in the quality of life of its citizens. The modeling involves the construction of a computational algorithm, which includes citizens, bounded into families; firms and governments; all of them interacting in markets for goods, labor and real estate. The real estate market allows families to move to dwellings with higher quality or lower price when the families capitalize property values. The goods market allows consumers to search on a flexible number of firms choosing by price and proximity. The labor market entails a matching process between firms (location) and candidates (qualification). The government may be configured into one, four or seven distinct sub-national governments. The role of government is to collect taxes on the value added of firms in its territory and invest the taxes into higher levels of quality of life for residents. The model does not have a credit market. The results suggest that the configuration of administrative boundaries is relevant to the levels of quality of life arising from the reversal of taxes. The model with seven regions is more dynamic, with higher GDP values, but more unequal and heterogeneous across regions. The simulation with only one region is more homogeneously poor. The study seeks to contribute to a theoretical and methodological framework as well as to describe, operationalize and test computer models of public finance analysis, with explicitly spatial and dynamic emphasis. Several alternatives of expansion of the model for future research are described. Moreover, this study adds to the existing literature in the realm of simple microeconomic computational models, specifying structural relationships between local governments and firms, consumers and dwellings mediated by distance.Comment: 27 pages, 25 figures, includes ODD Protocol and pseudocode

Knotted solutions, from electromagnetism to fluid dynamics

Knotted solutions to electromagnetism and fluid dynamics are investigated, based on relations we find between the two subjects. We can write fluid dynamics in electromagnetism language, but only on an initial surface, or for linear perturbations, and we use this map to find knotted fluid solutions, as well as new electromagnetic solutions. We find that knotted solutions of Maxwell electromagnetism are also solutions of more general nonlinear theories, like Born-Infeld, and including ones which contain quantum corrections from couplings with other modes, like Euler-Heisenberg and string theory DBI. Null configurations in electromagnetism can be described as a null pressureless fluid, and from this map we can find null fluid knotted solutions. A type of nonrelativistic reduction of the relativistic fluid equations is described, which allows us to find also solutions of the (nonrelativistic) Euler's equations.Comment: 36 pages, 3 figure

Collider and Gravitational Wave Complementarity in Exploring the Singlet Extension of the Standard Model

We present a dedicated complementarity study of gravitational wave and collider measurements of the simplest extension of the Higgs sector: the singlet scalar augmented Standard Model. We study the following issues: (i) the electroweak phase transition patterns admitted by the model, and the proportion of parameter space for each pattern; (ii) the regions of parameter space that give detectable gravitational waves at future space-based detectors; and (iii) the current and future collider measurements of di-Higgs production, as well as searches for a heavy weak diboson resonance, and how these searches interplay with regions of parameter space that exhibit strong gravitational wave signals. We carefully investigate the behavior of the normalized energy released during the phase transition as a function of the model parameters, address subtle issues pertaining to the bubble wall velocity, and provide a description of different fluid velocity profiles. On the collider side, we identify the subset of points that are most promising in terms of di-Higgs and weak diboson production studies while also giving detectable signals at LISA, setting the stage for future benchmark points that can be used by both communities.Comment: 38 pages, 22 figures. Version published in JHE