A Cauchy kernel for slice regular functions

In this paper we show how to construct a regular, non commutative Cauchy kernel for slice regular quaternionic functions. We prove an (algebraic) representation formula for such functions, which leads to a new Cauchy formula. We find the expression of the derivatives of a regular function in terms of the powers of the Cauchy kernel, and we present several other consequent results

What drives the substitutability between native and foreign workers?: evidence about the role of language

This paper investigates the role of language in determining the degree of substitutability between foreign and native workers. To this end, we focus on Switzerland, an immigration-receiving country with four official languages spoken, three of which in common with bordering countries. We modify the model proposed by Ottaviano and Peri (2012) to account for the linguistic background of native and immigrant workers. We find that language plays a central role in determining the elasticity of substitution between foreign and native workers and accounts for much of their imperfect substitutability. These findings are robust to a number of robustness checks, such as different specifications of the model structure and the inclusion of cross-border workers. Then, we compute the total wage change for native and foreign workers caused by new immigration in flows. In the long run, the average percentage wage changes for native and foreign workers are quite small and not significant

Extension results for slice regular functions of a quaternionic variable

In this paper we prove a new representation formula for slice regular functions, which shows that the value of a slice regular function $f$ at a point $q=x+yI$ can be recovered by the values of $f$ at the points $q+yJ$ and $q+yK$ for any choice of imaginary units $I, J, K.$ This result allows us to extend the known properties of slice regular functions defined on balls centered on the real axis to a much larger class of domains, called axially symmetric domains. We show, in particular, that axially symmetric domains play, for slice regular functions, the role played by domains of holomorphy for holomorphic functions

The role of culture in long-term care arrangement decisions

In this paper, we show how and to what extent cultural factors may influence the LTC market and elderly living arrangements. Using a spatial regression discontinuity design, we exploit the within-state variation in language groups in Switzerland to provide evidence about cultural differences in LTC use. We show that elderly people residing in regions speaking a Latin language (French, Italian and Romansh) enter nursing homes in worse health conditions and rely more on home-based care compared to elderly people residing in the neighboring German regions. Differences in the strength of family ties across linguistic groups represent the most reasonable explanation for such differences

The role of culture in long-term care

The aim of this paper is to assess the role of culture in shaping individual preferences to- wards different long-term care (LTC) arrangements. The analysis uses Swiss data from two administrative databases covering the universe of formal LTC providers between 2007 and 2013. Switzerland is a multi-cultural confederation where state administrative borders do not always coincide with cultural groups. For this reason, we exploit the within-state variation in cultural groups to show evidence about cultural differences in LTC use. In particular, we use spatial regression discontinuity design (RDD) at the language border between French-speaking and German-speaking individuals living in bilingual cantons to provide causal interpretation of the differences in formal LTC use between these two main cultural groups. Our results suggest a strong role of culture in shaping household decisions about formal LTC use. In particular, elderly people residing in regions speaking a Latin language (French, Italian and Romansh) use home-based care services more intensely and enter in nursing homes at older ages and in worse health conditions with respect to elderly people in German regions. This difference across the two cultural groups are driven by different preferences towards LTC arrangement

Three essays in labor economics

In this thesis, I investigate two of the main challenges faced by developed societies: aging and migration. In the first chapter, I consider the cultural determinants of elderly care arrangement decisions. The empirical strategy focuses on the three German and French speaking Swiss bilingual cantons. Particularly, since the structure of long-term care provision is planned at cantonal level, I compare the long-term care arrangement decisions of the elderly residing on either sides of the linguistic border. I find that on average people living in the French speaking part of bilingual cantons enter in nursing homes in worse health conditions and demand more home-based elderly care. These results are driven by differences in family ties and suggest that people with different cultural background may give different behavioral responses to the same public intervention. In the second chapter, I investigate the role of linguistic abilities in determining the substitutability between native and foreign workers. To this aim, I modify the model developed by Ottaviano and Peri (2012) and estimate some structural parameters, comparing workers of different nationalities and different linguistic backgrounds. The results show that migrant workers with the same linguistic background of native workers do not specialize in different occupations and are potentially perfect substitutes for native workers. By contrast, migrant workers with a different linguistic background tend to specialize in more manual intensive tasks and are somewhat complementary to resident natives. Finally, in the third chapter, I investigate whether firms play an active role in determining the labor demand for foreign workers. To this end, I replicate the empirical strategy of Autor et al. (2013), exploiting the upsurge of China as a world leading manufacturing exporter and instrumenting Chinese imports to the US with Chinese imports to other high income countries. The results show that an increase in import competition is positively related to the share of foreign workers employed, probably because of their greater productivity for a given salary. Given the negative impact of Chinese import competition on US employment, this effect on foreign workers may worsen the displacement of native workers, fostering anti-immigration feelings among the native population

Design of a beamline for soft and deep lithography on third generation synchrotron radiation source

ELETTRA is a third generation synchrotron radiation source. The energy spectrum allows the design of beamlines suitable for x-ray lithography from soft to hard x-ray wavelengths. An appropriate lithographic window for micro- and nanofabrication can be obtained by a combination of selected filters and mirrors. As the beamline is interfaced to a vertical x-ray stepper, a uniformity in the beam intensity better than 3% (3σ) in the horizontal direction has to be reached. The present beamline is designed by taking into account the main factors which can affect the beam quality, namely, thermal loading on mirrors and filters, slope errors, and surface roughness of the mirrors. The resulting lithographic resolution at soft x-ray wavelengths is better than 100 nm

A Functional Calculus in a Non Commutative Setting

In this paper we announce the development of a functional calculus for operators defined on quaternionic Banach spaces. The definition is based on a new notion of slice regularity, see [6], and the key tools are a new resolvent operator and a new eigenvalue problem. This approach allows us to deal both with bounded and unbounded operators

Design and Multiphysics Analysis of Direct and Cross-Coupled SIW Combline Filters Using Electric and Magnetic Couplings

In this paper, combline substrate integrated waveguide (SIW) filters using electric and magnetic couplings are thoroughly studied. Thus, a negative coupling scheme consisting on an open-ended coplanar probe is proposed and analyzed in detail. Several in-line 3-pole filters at C-band are designed, manufactured and measured showing how the presented approach can be used for implementing direct couplings while enabling an important size reduction and improved spurious-free band compared to conventional magnetic irises. A fully-packaged quasi-elliptic 4-pole filter is also designed at 5.75 GHz showing how the negative coupling structure can be used for introducing transmission zeros by means of cross-couplings between non-adjacent resonators. Finally, average and peak power handling capabilities of these filters have been also analyzed from a multiphysics point of view. Measured results validate the theoretical predictions confirming that combline SIW filters can handle significant levels of continuous and peak power, providing at the same time easy integration, compact size and advanced filtering responses.This work was supported in part by MINECO (Spanish Government) under projects TEC2013-47037-C5-1-R and TEC2013-48036-C3-3-R. This paper is an expanded version from the IEEE MTT-S International Microwave Symposium, Phoenix, AZ, USA, May 17-22, 2015.Sirci, S.; Sánchez Soriano, MÁ.; Martínez Pérez, JD.; Boria Esbert, VE.; Gentili, F.; Boesch, W.; Sorrentino, R. (2015). Design and Multiphysics Analysis of Direct and Cross-Coupled SIW Combline Filters Using Electric and Magnetic Couplings. IEEE Transactions on Microwave Theory and Techniques. 63(12):4341-4354. doi:10.1109/TMTT.2015.2495287S43414354631