Nonrelativistic Dirac fermions on the torus

Two dimensional conformal feld theories have been extensively studied in the past. When considered on the torus, they are strongly constrained by modular invariance. However, introducing relevant deformations or chemical potentials pushes these theories away from criticality, where many of their aspects are still poorly understood. In this note we make a step towards filling this gap, by analyzing the theory of a Dirac fermion on the torus, deformed by a mass term and a chemical potential for the particle number symmetry. The theory breaks conformal and Lorentz invariance, and we study its spectrum and partition function. We also focus on two limits that are interesting on their own right: a massless relativistic fermion with nonzero chemical potential (a simple model for CFTs at finite density), and nonrelativistic Schrodinger fermions (of relevance in condensed matter systems). Taking inspiration from recent developments in massive modular forms, we obtain a representation of the torus free energy based on Fourier-transforming over a twisted boundary condition. This dual representation fullfills many properties analogous to modular invariance in CFTs. In particular, we use this result to derive Cardy-like formulas for the high energy density of states of these theories.Comment: 23 pages, v2 reference adde

Diseño de un respondedor pasivo para un radar armónico de detección de objetos enterrados en nieve

El presente proyecto se basa en el sistema actual de búsqueda de víctimas de avalanchas conocido como Recco con el fin último de incrementar el número de rescates con éxito en este tipo de accidentes. Para ello nos proponemos ensayar un tipo de antena de parche que pueda ser útil para futuras mejoras del dicho sistema abriendo así una nueva línea de investigación. El principal objetivo es conseguir una unidad de microondas para las frecuencias de 0,9 GHz y 1,8 GHz, para ello usaremos un tipo de antena de parche con alimentación por acoplo de proximidad sobre tecnología de circuito impreso. Además de la antena añadiremos un circuido doblador, basando el conjunto en el funcionamiento tipo radar armónico autónomo, el cual, con una sola antena y sin alimentación externa para la electrónica implicada es capaz de recibir en f0 y transmitir en 2f0 simultáneamente. El PFC se dividirá en dos partes claramente diferenciadas, correspondientes a los dos bloques anteriormente descritos, la antena y el circuito. Para cada uno de los bloques se seguirán prácticamente los mismos pasos que serán los habituales en este tipo de estudios. A partir de unas especificaciones y un catálogo de componentes dadas obtendremos el diseño (dimensiones, formas, conexiones, etc.) que más se ajusten a los requerimientos previos. A continuación, llevaremos las dimensiones y valores obtenidos al software de simulación CST para la antena y Microwave Office para el circuito para comprobar y optimizar en caso que sea necesario, para obtener una respuesta lo mas fiel posible. Después de todos estos pasos diseñaremos los fotolitos para a continuación obtener las placas de circuito impreso. Montaremos el circuito físico y una vez montado, comprobaremos el funcionamiento mediante el uso de diferentes analizadores en pruebas en cámara anecoica.This Project deals with the improvement of the nowadays rescue systems used with avalanche victims. The final goal is to increase the number of success rescues in these kind of mountain accidents. The technology used is based in autonomous harmonic radar which, with just a single antenna and no external power is able to receive at f0 and transmit at 2f0 at the same time. This project deals with the study of the nowadays rescue systems used with avalanche victims. The final goal is to increase the number of success rescues in these kind of mountain accidents. To do this we propose to test a type of patch antenna that may be useful for future improvements of the system and opens a new line of research. The main objective is to get a microwave unit for frequencies 0.9 GHz and 1.8 GHz, for what we will use a type of patch antenna powered by direct coupling on printed circuit technology. Apart from the antenna we will also design a circuit doubler, basing the set in harmonic radar operation, which, with a single antenna without external power supply for the electronics involved is able to receive at f0 and transmit at 2f0 simultaneously. The PFC will be divided into two different parts corresponding to the two blocks described above, the antenna and the circuit. For each of the blocks similar steps will be followed, all of them typical in this kind of studies. From a specification and a catalog of components given we will obtain the design (dimensions, shapes, links, etc..) that best meet the previous requirements. Then take the dimensions and values obtained to simulation software CST for the antenna and Microwave Office for the circuit to test and optimize if necessary, to get an answer as accurate as possible. After these steps we will design the photolites in order to get the physical PCB. Then we will mount the physical circuit and once mounted, check the operation by using different analyzers in anechoic chamber tests.Ingeniería Técnica en Sistemas de Telecomunicació

Modelos conjuntos aplicados en la monitorización con pulsioximetría continua en una unidad de cuidados intermedios de neonatología

Fac. de Estudios EstadísticosTRUEpu

Activation of neuronal ensembles via controlled synchronization

"In this contribution we present the activation of neuronal ensembles of Hindmarsh-Rose neurons by controlled synchronization. The main problem consists in to impose a particular spiking-bursting behavior in all the neurons of the network. We consider a network where the neurons are in its resting state, it is desired that the neurons change their resting state to a particular behavior of activation, dictated by a neuron called the reference neuron. The goal is reached by controlling some neurons in the network controlling only the membrane potential (electrical synapse). The key feature of the present contribution is that by controlling a small number of neurons in the network a desired behavior is induced in all the neurons in the network despite its network topology. The important parameters are the control gain and the coupling strength, thus the activation of the network lays down on a compromise between the control gain and the coupling strength.

How non-Fermi liquids cure their infrared divergences

Non-Fermi liquids in d=2 spatial dimensions can arise from coupling a Fermi surface to a gapless boson. At finite temperature, however, the perturbative quantum field theory description breaks down due to infrared divergences. These are caused by virtual static bosonic modes and affect both fermionic and bosonic correlators. We show how these divergences are resolved by self-consistent boson and fermion self-energies that resum an infinite class of diagrams and correct the standard Eliashberg equations. Extending a previous approach in d=3-ϵ dimensions, we find a new "thermal non-Fermi liquid"regime that violates the scaling laws of the zero-temperature fixed point and dominates over a wide range of scales. We conclude that basic properties of quantum phase transitions and quantum-classical crossovers at finite temperature are modified in crucial ways in systems with soft bosonic fluctuations, and we begin a study of some of the phenomenological consequences.Fil: Aguilera Damia, Jeremías. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Solís Delgadillo, Juan Mario. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Torroba, Gonzalo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

Experiencia preprofesional en una empresa consultora de selección para cargos ejecutivos y gerenciales

El presente documento permite conocer las competencias desarrolladas como parte del perfil de egreso de la licenciatura en la PUCP mediante las Prácticas Pre-profesionales. El centro de prácticas en el cual se realizó este proceso fue una consultora privada, en el cual mi rol se dividió en tres funciones principales: 1. apoyar en la generación, desarrollo y consolidación de las relaciones comerciales con los clientes de la división, 2. alcanzar los indicadores clave de gestión por candidatos y por cliente, y, 3. entrevistar a candidatos usando técnicas de selección de la empresa para así escoger quienes son los más adecuados para los roles. Un problema constante identificado en la competencia Diagnostica era la percepción de la calidad del servicio que se brindaba a los clientes, por lo cual realicé entrevistas a estos mismos para elaborar un análisis FODA sobre el servicio brindado. En la competencia Interviene ejecuté el proceso de headhunting de acuerdo a los estándares de la compañía, a partir de lo cual identifiqué la oportunidad de mejorar del mismo. Por ello, debí recolectar información específica sobre los requerimientos de los clientes y realizar una comparación entre estos requerimientos con las características de los postulantes en las bases de datos. Finalmente, como parte de la competencia Evalúa, identifiqué que la mejora de la gestión del tiempo como un recurso importante para los colaboradores por lo cual realicé una pequeña intervención identificando elementos de mejora en este proceso.This document allows to know the competences developed as part of the graduate profile of the degree in the PUCP through the Pre-professional Practices. The internship center in which this process was carried out was a private consulting firm, in which my role was divided into three main functions: 1. supporting the generation, development and consolidation of commercial relationships with the division's clients, 2 achieve the key management indicators per candidate and per client, and 3. interview candidates using the company's selection techniques to choose who are the most suitable for the roles. A constant problem identified in the Diagnostics competition was the perception of the quality of the service provided to clients, for which I conducted interviews with them to prepare a SWOT analysis of the service provided. In the Intervene competition, I executed the headhunting process according to the company's standards, from which I identified the opportunity to improve it. Therefore, I had to collect specific information on the requirements of the clients and make a comparison between these requirements with the characteristics of the applicants in the databases. Finally, as part of the Evaluate competence, I identified the improvement of time management as an important resource for employees, for which I made a small intervention identifying elements of improvement in this process

Intestinal Microbiota and Weight-Gain in Preterm Neonates

The involvement of the gut microbiota on weight-gain and its relationship with childhood undernutrition and growth has been reported. Thus, the gut microbiota constitutes a potential therapeutic target for preventing growth impairment. However, our knowledge in this area is limited. In this study we aimed at evaluating the relationship among early microbiota, growth, and development in preterm infants. To this end we assessed the levels of specific microorganisms by qPCR, and those of short chain fatty acids by mean of gas-chromatography, in feces from 63 preterm newborns and determined their weight-gain during the first months. The statistical analyses performed indicate an influence of the intestinal microbiota in weight-gain, with the levels of some microorganisms showing a significant association with the weight-gain of the infant. The levels of specific microbial groups during the first days of life were found to affect weight gain by the age of 1 month. Moreover, clustering of the infants on the basis of the microbiota composition at 1 month of age rendered groups which showed differences in weight z-scores. Our results suggest an association between the gut microbiota composition and weight-gain in preterm infants at early life and point out potential microbial targets for favoring growth and maturation in these infants

iaBastos: An Intelligent Marketplace for Agricultural Products

In this paper we present a multi-agent platform designed to support p2p auctions on agricultural products. Experiments show that it could be feasible to integrate a platform, which is de-centralized by nature, into the current socioeconomic environment. The reason is that this market is managed by hard-centralized ecosystem, and experiments with our system show a significant reduction in marketing margins for the benefit of consumers and producers

Aspects of quantum information in finite density field theory

We study different aspects of quantum field theory at finite density using methods from quantum information theory. For simplicity we focus on massive Dirac fermions with nonzero chemical potential, and work in 1 + 1 space-time dimensions. Using the entanglement entropy on an interval, we construct an entropic c-function that is finite. Unlike what happens in Lorentz-invariant theories, this c-function exhibits a strong violation of monotonicity; it also encodes the creation of long-range entanglement from the Fermi surface. Motivated by previous works on lattice models, we next calculate numerically the Renyi entropies and find Friedel-type oscillations; these are understood in terms of a defect operator product expansion. Furthermore, we consider the mutual information as a measure of correlation functions between different regions. Using a long-distance expansion previously developed by Cardy, we argue that the mutual information detects Fermi surface correlations already at leading order in the expansion. We also analyze the relative entropy and its Renyi generalizations in order to distinguish states with different charge and/or mass. In particular, we show that states in different superselection sectors give rise to a super-extensive behavior in the relative entropy. Finally, we discuss possible extensions to interacting theories, and argue for the relevance of some of these measures for probing non-Fermi liquids.Fil: Daguerre, Lucas. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Medina, Raimel. Austria Institute of Technology; AustriaFil: Solís Delgadillo, Juan Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Universidad Nacional de Cuyo; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Torroba, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Universidad Nacional de Cuyo; Argentin

Experimental and Analytical Approach for the Assesment of Flexural Strength of Adobe Masonry

This paper presents an investigation about the flexural behavior of adobe masonry. It is focused on the development of constitutive models that can serve as a basis for the establishment of new design guidelines for adobe constructions, with special emphasis on seismic reinforcements. The paper analyzes the flexural behaviour of geogrid reinforced adobe walls. The experimental seismic tests of geogrid reinforced adobe houses have proven the effectiveness of the reinforcement technique. However, additional research is needed to develop constitutive models that can be used to quantify the actual performances of the reinforced adobe. For this purpose, bending tests have been carried out to obtain experimental curvature-moment relationships for reinforced and non reinforced adobe walls. Analytical models have been developed to approach these experimental laws, using equilibrium and compatibility equations similar to those usually applied for the flexural behaviour of reinforced concrete. The constitutive models of the individual materials are previously obtained through experimental tests, and simplified constitutive models are proposed for the governing equations. The analytical models show the ductility of adobe masonry, and how ductility increases when adobe is reinforced with geogrids. The proposed mathematical models and methodology can be applied to other structural elements and reinforcement systems. They can serve as a basis for the development of new design guidelines for adobe masonry