Angular momentum of S0 galaxies

The aim of this thesis is to study the angular momentum of a sample of S0 galaxies. In the quest to understand whether the formation of S0 galaxies is more closely linked to that of ellipticals or that of spirals, our goal is to compare the amount of their specific angular momentum as a function of stellar mass with respect to spirals. Through kinematic comparison between these different classes of galaxies we aim to understand if a scenario of passive evolution, in which the galaxy’s gas is consumed and the star formation is quenched, can be considered as plausible mechanism to explain the transformation from spirals to S0s. In order to derive the structural and photometric parameters of galaxy sub-components we performed a bulge-disc decomposition of optical images using GALFIT. The stellar kinematic of the galaxies was measured using integral field spectroscopic data from CALIFA survey. The development of new original software, based on a Monte Carlo Markov Chain algorithm, allowed us to obtain the values of the line of sight velocity and velocity dispersion of disc and bulge components. The result that we obtained is that S0 discs have a distribution of stellar specific angular momentum that is in full agreement with that of spiral discs, so the mechanism of simple fading can be considered as one of the most important for transformation from spirals to S0s.

Design and modeling of optical fibers for spatial division multiplexing using the orbital angular momentum of light

Les besoins toujours croissants en terme de transfert de données numériques poussent au développement de nouvelles technologies pour accroître la capacité des réseaux, notamment en ce qui concerne les réseaux de fibre optique. Parmi ces nouvelles technologies, le multiplexage spatial permet de multiplier la capacité des liens optiques actuels. Nous nous intéressons particulièrement à une forme de multiplexage spatial utilisant le moment cinétique orbital de la lumière comme base orthogonale pour séparer un certain nombre de canaux. Nous présentons d’abord les notions d’électromagnétisme et de physique nécessaires à la compréhension des développements ultérieurs. Les équations de Maxwell sont dérivées afin d’expliquer les modes scalaires et vectoriels de la fibre optique. Nous présentons également d’autres propriétés modales, soit la coupure des modes, et les indices de groupe et de dispersion. La notion de moment cinétique orbital est ensuite introduite, avec plus particulièrement ses applications dans le domaine des télécommunications. Dans une seconde partie, nous proposons la carte modale comme un outil pour aider au design des fibres optiques à quelques modes. Nous développons la solution vectorielle des équations de coupure des modes pour les fibres en anneau, puis nous généralisons ces équations pour tous les profils de fibres à trois couches. Enfin, nous donnons quelques exemples d’application de la carte modale. Dans la troisième partie, nous présentons des designs de fibres pour la transmission des modes avec un moment cinétique orbital. Les outils développés dans la seconde partie sont utilisés pour effectuer ces designs. Un premier design de fibre, caractérisé par un centre creux, est étudié et démontré. Puis un second design, une famille de fibres avec un profil en anneau, est étudié. Des mesures d’indice effectif et d’indice de groupe sont effectuées sur ces fibres. Les outils et les fibres développés auront permis une meilleure compréhension de la transmission dans la fibre optique des modes ayant un moment cinétique orbital. Nous espérons que ces avancements aideront à développer prochainement des systèmes de communications performants utilisant le multiplexage spatial.

Third Quarter 2016: Hotels Exhibit Positive Momentum

Our Standardized Unexpected Price (SUP) metric showed an uptick in the price of large hotels during the third quarter of 2016, with a continued decline in the price of small hotels. Although debt and equity financing for hotels were still relatively inexpensive during this quarter, we remain concerned that the increasing relative riskiness of hotels compared to other commercial real estate suggests that lenders will eventually start to tighten hotel lending standards if this trend continues. Our early warning indicators continue to suggest an eventual downward trend in large hotel prices. This is report number 20 of the index series.

Employability, Skills Development and Enterprise Creation (Momentum, University of Worcester)

Background to the Momentum project : PSS1 (Sept 2014 - July 2016): funded by HEFCE to promote Postgraduate Education and Employability. A discussion of group demographics, student experience, employer feedback, and enterprise creation through the establishment of the University of Worcester Business Incubator. The presentation concludes with a number of lessons learned from the project.

Determinantes de momentum en acciones del mercado integrado de Latinoamérica

Se denomina momentum a la tendencia de ciertos activos financieros a generar retornos que están relacionados positivamente con los retornos que han obtenido en el pasado reciente. En principio, se distinguen dos tipos de momentum. El primer tipo, a nivel de sección cruzada, se observa en grupos de activos financieros cuando aquellos instrumentos que han tenido un rendimiento relativamente superior o inferior en el pasado, mantienen el mismo desempeño relativo a futuro. El segundo tipo, a nivel de serie de tiempo, se observa cuando el desempeño de un activo en particular tiene un fuerte componente autorregresivo positivo. Esta investigación se enfoca principalmente en el momentum de sección cruzada. Como se detallará más adelante, el momentum ha sido documentado en muchos mercados, pero no existe un consenso sobre las causas que lo motivan. Los objetivos de esta investigación son, primero, identificar si existe momentum en los mercados de acciones de Chile, Colombia, México y Perú. Segundo, contribuir a la literatura internacional tratando de analizar cuáles son las causas del momentum. Los resultados de esta investigación confirman que existe momentum en los mercados de acciones analizados y bridan apoyo parcial a las teorías, basadas en finanzas conductuales (behavioral finance) que se han postulado para explicar el momentum.

Construcción y evaluación de un portafolio estructural, para obligatorias retiro programado, utilizando la metodología de frontera eficiente de Markowitz y la Teoría de Momentum

Este proyecto de investigación construye y evalúa la asignación de activos para el portafolio de Pensión Obligatoria de Retiro Programado, el cual atiende los retiros a los que un pensionado tiene derecho a través de su mesada pensional, utilizando el modelo de Frontera Eficiente de Markowitz, en combinación con la teoría de Momentum -- Para la ejecución del modelo se determinaron los activos de inversión admisibles en el Régimen de Inversiones -- Posteriormente, se construyen las matrices de rentabilidades, de restricciones, de varianzas y covarianzas, las cuales constituyen los insumos para ejecutar el modelo de optimización de portafolios de Markowitz -- A continuación, se realiza la selección de los portafolios obtenidos, teniendo en cuenta el nivel de volatilidad que el portafolio de Obligatorias Retiro Programado debe presentar; lo anterior, con el fin de cumplir con el objetivo de preservación del capital en la cuenta individual del pensionado, de manera que se pueda atender, de acuerdo a su esperanza de vida y la de sus beneficiarios, el pago de las mesadas pensionales que le correspondan -- El resultado obtenido corresponde a una asignación, en gran parte, en activos de Renta Fija expedidos por el Gobierno Nacional (TES), tanto en tasa fija como en tasa indexada a la UVR -- Adicionalmente, el modelo de optimización sugiere participaciones en activos de renta variable y, particularmente, no asigna recursos representativos en títulos de deuda privada indexados al IPC -- Esta investigación puede ser útil al momento de diseñar un portafolio base para Obligatorias Retiro Programado que, bajo una administración pasiva, permita cumplir el objetivo de otorgar a los pensionados una mesada para satisfacer las necesidades básicas

Unpolarized transverse momentum dependent parton distribution and fragmentation functions at next-to-next-to-leading order

The transverse momentum dependent parton distribution/fragmentation functions (TMDs) are essential in the factorization of a number of processes like Drell-Yan scattering, vector boson production, semi-inclusive deep inelastic scattering, etc. We provide a comprehensive study of unpolarized TMDs at next-to-next-to-leading order, which includes an explicit calculation of these TMDs and an extraction of their matching coefficients onto their integrated analogues, for all flavor combinations. The obtained matching coefficients are important for any kind of phenomenology involving TMDs. In the present study each individual TMD is calculated without any reference to a specific process. We recover the known results for parton distribution functions and provide new results for the fragmentation functions. The results for the gluon transverse momentum dependent fragmentation functions are presented for the first time at one and two loops. We also discuss the structure of singularities of TMD operators and TMD matrix elements, crossing relations between TMD parton distribution functions and TMD fragmentation functions, and renormalization group equations. In addition, we consider the behavior of the matching coefficients at threshold and make a conjecture on their structure to all orders in perturbation theory.

Carrier momentum relaxation in highly doped polar semiconductors and semiconductor heterostructures

Highly doped polar semiconductors are essential components of today’s semiconductor industry. Most strikingly, transistors in modern electronic devices are polar semiconductor heterostructures. It is important to thoroughly understand carrier transport in such structures. In doped polar semiconductors, collective excitations of the carriers (plasmons) and the atoms (polar phonons) couple. These coupled collective excitations affect the electrical conductivity, here quantified through the carrier mobility. In scattering events, the carriers and the coupled collective modes transfer momentum between each other. Carrier momentum transferred to polar phonons can be lost to other phonons through anharmonic decay, resulting in a finite carrier mobility. The plasmons do not have a decay mechanism which transfers carrier momentum irretrievably. Hence, carrier-plasmon scattering results in infinite carrier mobility. Momentum relaxation due to either carrier–plasmon scattering or carrier–polar-phonon scattering alone are well understood. However, only this thesis manages to treat momentum relaxation due to both scattering mechanisms on an equal footing, enabling us to properly calculate the mobility limited by carrier–coupled plasmon–polar phonon scattering. We achieved this by solving the coupled Boltzmann equations for the carriers and the collective excitations, focusing on the “drag” term and on the anharmonic decay process of the collective modes. Our approach uses dielectric functions to describe both the carrier-collective mode scattering and the decay of the collective modes. We applied our method to bulk polar semiconductors and heterostructures where various polar dielectrics surround a semiconducting monolayer of MoS2, where taking plasmons into account can increase the mobility by up to a factor 15 for certain parameters. This screening effect is up to 85% higher than if calculated with previous methods. To conclude, our approach provides insight into the momentum relaxation mechanism for carrier–coupled collective mode scattering, and better tools for calculating the screened polar phonon and interface polar phonon limited mobility.

Shaken not stirred: creating exotic angular momentum states by shaking an optical lattice

We propose a method to create higher orbital states of ultracold atoms in the Mott regime of an optical lattice. This is done by periodically modulating the position of the trap minima (known as shaking) and controlling the interference term of the lasers creating the lattice. These methods are combined with techniques of shortcuts to adiabaticity. As an example of this, we show specifically how to create an anti-ferromagnetic type ordering of angular momentum states of atoms. The specific pulse sequences are designed using Lewis-Riesenfeld invariants and a fourlevel model for each well. The results are compared with numerical simulations of the full Schrodinger equation.

Creative Industries come to China (MATE)

This paper introduces the special issue “China: Internationalizing the Creative Industries”, describing the Australian Research Council funded “MATE” project which provides the conceptual background for the questions the issue explores. The MATE project began with the expectation that as China evolves from its status as a developing country with an emphasis on primary industries and manufacturing, to a mature, market-driven economy benefiting from high levels of international investment, it will become more actively engaged with the global “knowledge economy” and “information society”. In this context, developments in the “creative industries”, which are playing such an important role in developed economies, might reasonably be expected in China. Although China continues to be characterised by strong central-policy settings, as the domestic consumer market matures there is greater scope for consumer-led creative business development. The “MATE” project aimed to capture some of these changes as they began to gain momentum across a range of services: Media, Advertising, Tourism and Education. This special issue continues this theme with papers that explore the theoretical challenges, economic questions and implications, and practical instantiations of creative industries growth in China. All papers contained in this special issue have been peer-reviewed.

Data mining on prices of highway project main material based on WEB

The management of main material prices of provincial highway project quota has problems of lag and blindness. Framework of provincial highway project quota data MIS and main material price data warehouse were established based on WEB firstly. Then concrete processes of provincial highway project main material prices were brought forward based on BP neural network algorithmic. After that standard BP algorithmic, additional momentum modify BP network algorithmic, self-adaptive study speed improved BP network algorithmic were compared in predicting highway project main prices. The result indicated that it is feasible to predict highway main material prices using BP NN, and using self-adaptive study speed improved BP network algorithmic is the relatively best one.