The Covariant Phase Space of Gravity with Boundaries

This thesis investigates the metric and tetrad formulations of three gravitational field theories in manifolds with timelike boundaries within the covariant phase space program. With the recently developed relative bicomplex framework, we explore the space of solutions and presymplectic structures associated with each action principle and analyse their equivalence. The first action we consider is the Einstein-Hilbert (EH) action with the Gibbons- Hawking-York boundary term. By including the appropriate boundary terms in the variational principles, we show that the metric and tetrad formulations derived from them are equivalent. Furthermore, we show that their solution spaces are the same and that their presymplectic structures and associated charges coincide. The second action we consider is the Palatini action with the Obukhov boundary term, assuming torsion and non-metricity, and we prove the equivalence between its metric and tetrad formulations. Furthermore, we show that the metric and tetradsector of the first-order Palatini formulation are equivalent to the metric and tetrad formulations of the EH action. Lastly, we introduce the Hojman-Mukku-Sayed (HMS) action, a generalisation of the Palatini action plus the Holst term in the presence of boundaries with non-metricity and torsion. We prove that the space of solutions of the HMS and Palatini actions coincided and conclude that HMS’s metric and tetrad sectors are identical to their corresponding versions of the EH action. Additionally, we prove that the Palatini and HMS Lagrangians are not cohomologically equal despite defining the same space of solutions. Consequently, a careful analysis is required for the presymplectic structures and the charges because they may differ. However, we show that the covariant phase spaces of both theories were equivalent. This sheds light on some open problems regarding the equivalence of their associated charges in different formulations.Programa de Doctorado en Ingeniería Matemática por la Universidad Carlos III de MadridPresidente: José Navarro Salas.- Secretario: Bogar Díaz Jiménez.- Vocal: Mercedes Martín Benit

Precise Image Generation on Current Noisy Quantum Computing Devices

The Quantum Angle Generator (QAG) is a new full Quantum Machine Learning model designed to generate accurate images on current Noise Intermediate Scale (NISQ) Quantum devices. Variational quantum circuits form the core of the QAG model, and various circuit architectures are evaluated. In combination with the so-called MERA-upsampling architecture, the QAG model achieves excellent results, which are analyzed and evaluated in detail. To our knowledge, this is the first time that a quantum model has achieved such accurate results. To explore the robustness of the model to noise, an extensive quantum noise study is performed. In this paper, it is demonstrated that the model trained on a physical quantum device learns the noise characteristics of the hardware and generates outstanding results. It is verified that even a quantum hardware machine calibration change during training of up to 8% can be well tolerated. For demonstration, the model is employed in indispensable simulations in high energy physics required to measure particle energies and, ultimately, to discover unknown particles at the Large Hadron Collider at CERN

On-shell equivalence of general relativity and Holst theories with nonmetricity, torsion, and boundaries

We study a generalization of the Holst action where we admit nonmetricity and torsion in manifolds with timelike boundaries (both in the metric and tetrad formalism). We prove that its space of solutions is equal to the one of the Palatini action. Therefore, we conclude that the metric sector is in fact identical to general relativity (GR), which is defined by the Einstein-Hilbert action. We further prove that, despite defining the same space of solutions, the Palatini and (the generalized) Holst Lagrangians are not cohomologically equal. Thus, the presymplectic structure and charges provided by the covariant phase space method might differ. However, using the relative bicomplex framework, we show the covariant phase spaces of both theories are equivalent (and in fact equivalent to GR), as well as their charges, clarifying some open problems regarding dual charges and their equivalence in different formulations.This work has been supported by the Spanish Ministerio de Ciencia Innovación y Universidades-Agencia Estatal de Investigación FIS2017-84440-C2-2-P and PID2020-116567GB-C22 grants. Juan Margalef-Bentabol is supported by the AARMS postdoctoral fellowship, by the NSERC Discovery Grant No. 2018-04873, and the NSERC Grant RGPIN-2018-04887. E.J.S. Villaseñor is supported by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with UC3M in the line of Excellence of University Professors (EPUC3M23), and in the context of the V PRICIT (Regional Programme of Research and Technological Innovation)

TICs to improve scientific reasoning capacity as a strategy for Engineering problem resolution

En este proyecto se ha diseñado una nueva metodología docente de resolución de problemas en asignaturas científico-técnicas, basada en el uso de recursos TIC, con el objetivo de fomentar la adquisición de la competencia de razonamiento científico. Concretamente, por un lado, en las sesiones presenciales, se han utilizado los sistemas de respuesta interactiva cuyo éxito en el aula ya ha sido comprobado por los autores. Por otro lado, para el trabajo del alumnado fuera del aula, se ha integrado el uso de la herramienta interactiva online (web 2.0) elearningphysics, desarrollada por los autores que, mediante flujos de preguntas concatenadas, guía al estudiante durante la resolución de problemas ayudándole a razonar el porqué de los conceptos y leyes aplicados. Se ha comprobado que ambos recursos TICs contribuyen a que el alumnado adquiera la competencia de razonamiento científico aplicada a la resolución de problemas en asignaturas científico-técnicas, ya que le ayudan a relacionar los conceptos teóricos y prácticos a la vez que aumentan su nivel de motivación y participación en las actividades de resolución de problemas.In this project a new teaching methodology, based on the use of ICT resources, has been designed for problem solving in scientific and technical subjects. Its aim is to promote the acquisition of scientific reasoning competence. Specifically, in classroom, interactive response systems have been used. Additionally, the online interactive tool (web 2.0) elearningphysics, developed by the authors, has been proposed to students to work at home. This tool, through concatenated questions, guides students during problem solving by helping them to understand the concepts and laws applied. It has been proved that both ICT resources help students to acquire the competence of scientific reasoning applied to problem solving in scientific and technical subjects. Particularly, these resources help students to stablish relationships between theoretical and practical concepts at the same time that they increase students’ level of motivation and participation in problem-solving activities

Not all cows are epidemiologically equal:quantifying the risks of bovine viral diarrhoea virus (BVDV) transmission through cattle movements

International audienceMany economically important cattle diseases spread between herds through livestock movements. Traditionally, most transmission models have assumed that all purchased cattle carry the same risk of generating outbreaks in the destination herd. Using data on bovine viral diarrhoea virus (BVDV) in Scotland as a case example, this study provides empirical and theoretical evidence that the risk of disease transmission varies substantially based on the animal and herd demographic characteristics at the time of purchase. Multivariable logistic regression analysis revealed that purchasing pregnant heifers and open cows sold with a calf at foot were associated with an increased risk of beef herds being seropositive for BVDV. Based on the results from a dynamic within-herd simulation model, these findings may be partly explained by the age-related probability of animals being persistently infected with BVDV as well as the herd demographic structure at the time of animal introductions. There was also evidence that an epidemiologically important network statistic, "betweenness centrality" (a measure frequently associated with the potential for herds to acquire and transmit disease), was significantly higher for herds that supplied these particular types of replacement beef cattle. The trends for dairy herds were not as clear, although there was some evidence that open heifers and open lactating cows were associated with an increased risk of BVDV. Overall, these findings have important implications for developing simulation models that more accurately reflect the industry-level transmission dynamics of infectious cattle diseases

Precise Image Generation on Current Noisy Quantum Computing Devices

The quantum angle generator (QAG) is a new full quantum machine learning model designed to generate accurate images on current noise intermediate scale quantum devices. Variational quantum circuits form the core of the QAG model, and various circuit architectures are evaluated. In combination with the so-called MERA-upsampling architecture, the QAG model achieves excellent results, which are analyzed and evaluated in detail. To our knowledge, this is the first time that a quantum model has achieved such accurate results. To explore the robustness of the model to noise, an extensive quantum noise study is performed. In this paper, it is demonstrated that the model trained on a physical quantum device learns the noise characteristics of the hardware and generates outstanding results. It is verified that even a quantum hardware machine calibration change during training of up to 8% can be well tolerated. For demonstration, the model is employed in indispensable simulations in high energy physics required to measure particle energies and, ultimately, to discover unknown particles at the large Hadron Collider at CERN.The Quantum Angle Generator (QAG) is a new full Quantum Machine Learning model designed to generate accurate images on current Noise Intermediate Scale (NISQ) Quantum devices. Variational quantum circuits form the core of the QAG model, and various circuit architectures are evaluated. In combination with the so-called MERA-upsampling architecture, the QAG model achieves excellent results, which are analyzed and evaluated in detail. To our knowledge, this is the first time that a quantum model has achieved such accurate results. To explore the robustness of the model to noise, an extensive quantum noise study is performed. In this paper, it is demonstrated that the model trained on a physical quantum device learns the noise characteristics of the hardware and generates outstanding results. It is verified that even a quantum hardware machine calibration change during training of up to 8% can be well tolerated. For demonstration, the model is employed in indispensable simulations in high energy physics required to measure particle energies and, ultimately, to discover unknown particles at the Large Hadron Collider at CERN

Three roads to the geometric constraint formulation of gravitational theories with boundaries

23 pags., 2 figs. -- This article belongs to the Special Issue Black Holes, Cosmology, Quantum Gravity, and Their SymmetriesThe Hamiltonian description of mechanical or field models defined by singular Lagrangians plays a central role in physics. A number of methods are known for this purpose, the most popular of them being the one developed by Dirac. Here, we discuss other approaches to this problem that rely on the direct use of the equations of motion (and the tangency requirements characteristic of the Gotay, Nester and Hinds method), or are formulated in the tangent bundle of the configuration space. Owing to its interesting relation with general relativity we use a concrete example as a test bed: an extension of the Pontryagin and Husain–Kuchař actions to four dimensional manifolds with boundary.This work has been supported by the Spanish Ministerio de Ciencia Innovación y Universidades-Agencia Estatal de Investigación FIS2017-84440-C2-2-P and PID2020-116567GB-C22 grants. E.J.S. Villaseñor is supported by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with UC3M in the line of Excellence of University Professors (EPUC3M23), and in the context of the V PRICIT (Regional Programme of Research and Technological Innovation

RECURSOS TICS ORIENTADOS A MEJORAR LA CAPACIDAD DE RAZONAMIENTO CIENTÍFICO COMO ESTRATEGIA DE RESOLUCIÓN DE PROBLEMAS DE INGENIERÍA

In this project a new teaching methodology, based on the use of ICT resources, has been designed for problem solving in scientific and technical subjects. Its aim is to promote the acquisition of scientific reasoning competence. Specifically, in classroom, interactive response systems have been used. Additionally, the online interactive tool (web 2.0) elearningphysics, developed by the authors, has been proposed to students to work at home. This tool, through concatenated questions, guides students during problem solving by helping them to understand the concepts and laws applied. It has been proved that both ICT resources help students to acquire the competence of scientific reasoning applied to problem solving in scientific and technical subjects. Particularly, these resources help students to stablish relationships between theoretical and practical concepts at the same time that they increase students’ level of motivation and participation in problem-solving activities.En este proyecto se ha diseñado una nueva metodología docente de resolución de problemas en asignaturas científico-técnicas, basada en el uso de recursos TIC, con el objetivo de fomentar la adquisición de la competencia de razonamiento científico. Concretamente, por un lado, en las sesiones presenciales, se han utilizado los sistemas de respuesta interactiva cuyo éxito en el aula ya ha sido comprobado por los autores. Por otro lado, para el trabajo del alumnado fuera del aula, se ha integrado el uso de la herramienta interactiva online (web 2.0) elearningphysics, desarrollada por los autores que, mediante flujos de preguntas concatenadas, guía al estudiante durante la resolución de problemas ayudándole a razonar el porqué de los conceptos y leyes aplicados. Se ha comprobado que ambos recursos TICs contribuyen a que el alumnado adquiera la competencia de razonamiento científico aplicada a la resolución de problemas en asignaturas científico-técnicas, ya que le ayudan a relacionar los conceptos teóricos y prácticos a la vez que aumentan su nivel de motivación y participación en las actividades de resolución de problemas