El Mercado Laboral Urbano: Empleo, Desempleo y Salario Real en Colombia entre 1985 y 1996

Se estimó un modelo neo-clásico del mercado laboral, con respuestas lentas o ajustes parciales, para el caso de la evolución del empleo, el desempleo transitorio (definido como la diferencia entre el desempleo total y el permanente) y el salario real en el conjunto de las siete principales ciudades colombianas entre 1985 y 1996. Los resultados son consistentes con el modelo supuesto y, en particular, muestran que el empleo es sensible al salario real y al desempleo transitorio, y recíprocamente. Además, tanto el empleo como el desempleo transitorio y el salario real dependen simultáneamente de las tres variables exógenas incorporadas en el modelo: el producto, el costo de uso del capital y la población en edad de trabajar. En equilibrio, al cual tiende el mercado según el modelo, el desempleo transitorio es nulo, así que la tasa desempleo se hace igual a la permanente.

Non-reciprocal few-photon devices based on chiral waveguide-emitter couplings

We demonstrate the possibility of designing efficient, non reciprocal few-photon devices by exploiting the chiral coupling between two waveguide modes and a single quantum emitter. We show how this system can induce non-reciprocal photon transport at the single-photon level and act as an optical diode. Afterwards, we also show how the same system shows a transistor-like behaviour for a two-photon input. The efficiency in both cases is shown to be large for feasible experimental implementations. Our results illustrate the potential of chiral waveguide-emitter couplings for applications in quantum circuitry.Comment: Mathematica notebook attached for calculation of detection probabilitie

On the Determination of Leptonic CP Violation and Neutrino Mass Ordering in Presence of Non-Standard Interactions: Present Status

We perform a global analysis of neutrino data in the framework of three massive neutrinos with non-standard neutrino interactions which affect their evolution in the matter background. We focus on the effect of NSI in the present observables sensitive to leptonic CP violation and to the mass ordering. We consider complex neutral current neutrino interactions with quarks whose lepton-flavor structure is independent of the quark type. We quantify the status of the "hints" for CP violation, the mass-ordering and non-maximality of $\theta_{23}$ in these scenarios. We also present a parametrization-invariant formalism for leptonic CP violation in presence of a generalized matter potential induced by NSI.Comment: 24 pages, 4 figure

A chiral route to spontaneous entanglement generation

We study the generation of spontaneous entanglement between two qubits chirally coupled to a waveguide. The maximum achievable concurrence is demonstrated to increase by a factor of $4/e \sim 1.5$ as compared to the non-chiral coupling situation. The proposed entanglement scheme is shown to be robust against variation of the qubit properties such as detuning and separation, which are critical in the non-chiral case. This result relaxes the restrictive requirements of the non-chiral situation, paving the way towards a realistic implementation. Our results demonstrate the potential of chiral waveguides for quantum entanglement protocols.Comment: 5 pages + 1 page supplemental, 4 figure

La pédagogie de l’inattendu

Pour améliorer l’attention des étudiants et la synergie dans nos cours de biologie, nous avons créé ce que nous appelons la pédagogie de l’inattendu où nous utilisons des activités auxquelles l’étudiant n’est pas habitué (sketches et démonstrations à base de crayons, papiers et lumières). Ces activités visent à faire sortir l’étudiant de sa zone de confort et à l’émerveiller en faisant appel à ses émotions et à son imaginaire pour lui faire apprendre des concepts complexes.Lien vers une vidéo seulement. Ne contient pas de texte

Galaxy Formation in the Lambda-Cold Dark Matter Cosmology

In this thesis I explore the effects of the various physical processes behind galaxy formation and evolution in hierarchical cosmologies by using semi-analytical modelling. I use the Durham semi-analytical model GALFORM. I first test the GALFORM model predictions using observations from the Sloan Digital Sky Survey (SDSS). I use two different variants of the model, Baugh et al (2005), which assumes a top-heavy initial mass function (IMF) in starbursts and superwind feedback, and Bower et al (2006), which incorporates AGN feedback with a standard IMF. I compare the luminosity function, colours, sizes and morphology distributions of present-day galaxies in the models and with the SDSS. The Bower et al model better reproduces the shape of the luminosity function, the morphology-luminosity relation and the colour bimodality observed in the SDSS data. The Baugh et al model is much more successful at predicting galaxy sizes for late-type galaxies. Both models have problems with the sizes of early-type galaxies, which are predicted to be too large for low luminosities and too small for high luminosities compared to SDSS. I tested the impact on the model predictions of varying the prescriptions for supernova feedback, disk instabilities and galaxy mergers. In the second part of the thesis I explore the connection between two high redshift star-forming galaxy populations and present-day galaxies and their contribution to the star formation history. I built galaxy merger trees and followed the evolution and properties of submillimetre galaxies (SMGs) and Lyman-break galaxies (LBGs) using the Baugh et al (2005) model. The model predicts that the descendants of SMGs (S_{nu} > 5 mJy) have a median stellar mass of ~10e11/h solar masses, and that more than 70% of these descendants are bulge-dominated. More than 50% of present-day galaxies with stellar masses larger than 7 x 10e11/h solar masses are predicted to be descendants of such SMGs. Somewhat controversially, the stellar mass produced in the submillimetre phase contributes only 0.2% of the total present-day stellar mass, and 2% of the stellar mass of SMG descendants. The descendants of z=3 LBGs are predicted to have a median stellar mass equal to that of the Milky Way (M = 4 x 10e10/h solar masses), while the descendants of z=6 LBGs are predicted to have a larger median stellar mass (M = 10e11/h solar masses). The model predicts that only one in every 16 and one in every 50 Milky Way mass galaxies have a Lyman-break galaxy progenitor at z=3 and z=6 respectively

Harvesting Excitons Through Plasmonic Strong Coupling

Exciton harvesting is demonstrated in an ensemble of quantum emitters coupled to localized surface plasmons. When the interaction between emitters and the dipole mode of a metallic nanosphere reaches the strong coupling regime, the exciton conductance is greatly increased. The spatial map of the conductance matches the plasmon field intensity profile, which indicates that transport properties can be tuned by adequately tailoring the field of the plasmonic resonance. Under strong coupling, we find that pure dephasing can have detrimental or beneficial effects on the conductance, depending on the effective number of participating emitters. Finally, we show that the exciton transport in the strong coupling regime occurs on an ultrafast timescale given by the inverse Rabi splitting ($\sim10~$fs), orders of magnitude faster than transport through direct hopping between the emitters.Comment: 5 pages, 3 figure

When the element of surprise fosters learning

Comprend des références bibliographiquesAt the 2015 AQPC symposium in Saguenay, the Editor-in-Chief had registered for an intriguing workshop titled “Pedagogy of the Unexpected.” She found herself in a room filled with strands of miniature lights, intriguing models and peculiar installations that helped her easily understand the process of synaptic transmission in neurons. The workshop fascinated her, threw her off balance and pulled her outside her comfort zone, which made her want to meet the speakers to learn more about their teaching methods that harness the element of surprise, curiosity and humour as sources of motivation to promote learning