Surface Photometry of Early-type Galaxies in the Hubble Deep Field

The detailed surface photometry of a sample of early-type galaxies in the Hubble Deep Field is presented as part of a long-term project aimed to settle strong observational constraints to the theories modelling the evolution of elliptical galaxies from the early stages. The sample has been extracted, in the V_606 band, from the catalog by Couch (1996). The analysis of the luminosity and geometrical profiles, carried out on 162 candidates obeying our provisional selection criteria, resulted in a list of 99 'bona fide' early-type galaxies, for which accurate total magnitudes and effective radii were computed. The comparison with the magnitudes given by Williams et al.(1996) indicates that the automated photometry tends to underestimate the total luminosity of the ellipticals. The luminosity profiles of most of galaxies in our sample follow fairly well the deVaucouleurs law (`Normal' profiles). However, a relevant fraction of galaxies, even following the deVaucouleurs law in the main body light distribution, exhibit in the inner region a flattening of the luminosity profile not attributable to the PSF (`Flat' profiles) or, in some cases, a complex (multi-nucleus) structure (`Merger' profiles). The average ellipticity of galaxies belonging to the `Flat' and `Merger' classes is found to be significantly higher than that of the `Normal' galaxies. Moreover, even taken into account the relevant uncertainty of the outer position angle profiles, the amount of isophotal twisting of HDF ellipticals turns out to be significantly larger with respect to that of the local samples.Comment: 22 pages, LaTeX with laa.sty and psfig.sty macros + 28 embedded postscript figures. To appear in Astronomy and Astrophysics Supp

Globalization in Latin America Before 1940

How much of the good growth performance in Latin America between 1870 and 1913 can be assigned to the forces of globalization? Why was industrialization so weak? Why was inequality on the rise? This paper offers an answer to these questions. It starts by exploring the disadvantages associated with geographic isolation from world markets and the transport revolutions that helped liberate Latin America from that isolation, a pro-global force. It then asks how independence contributed to massive de-globalization during the decades of lost growth' between the 1820s and the 1870s. Next, it documents what happened to the external terms of trade in Latin America between 1820 and 1950: from the 1890s onwards the terms of trade deteriorated, but it also underwent spectacular improvement before the 1890s, suggesting that it had something to do with the fairly fast' Latin America growth during so much of the belle ‚poque. While booming relative prices of exports certainly fostered trade, policy suppressed it: tariff rates were higher in Latin America than almost anywhere else in the world between 1820 and 1929, long before the Great Depression. The paper then asks why. The answer is to be found mainly with revenue needs rather than with some precocious import substitution policy. High tariffs still had a powerful protective effect, regardless of motivation. However, protective policy was modified by those powerful and positive terms of trade shocks, yielding on net weak early industrialization. Finally, the paper documents that inequality rose in most of Latin America up to World War I, while it fell thereafter. The correlation between globalization and inequality is likely to have been causal.

The Cauchy two-matrix model

We introduce a new class of two(multi)-matrix models of positive Hermitean matrices coupled in a chain; the coupling is related to the Cauchy kernel and differs from the exponential coupling more commonly used in similar models. The correlation functions are expressed entirely in terms of certain biorthogonal polynomials and solutions of appropriate Riemann-Hilbert problems, thus paving the way to a steepest descent analysis and universality results. The interpretation of the formal expansion of the partition function in terms of multicolored ribbon-graphs is provided and a connection to the O(1) model. A steepest descent analysis of the partition function reveals that the model is related to a trigonal curve (three-sheeted covering of the plane) much in the same way as the Hermitean matrix model is related to a hyperelliptic curve.Comment: 34 pages, 2 figures. V2: changes only to metadat

A thermo-economic based method for the design of process heat solar systems

In this paper, the perspectives of production of thermal energy for industrial process heat from solar energy are considered. This represents a quite relevant topic for an overall containment of using fossil fuels with the objectives of reducing the impact of fossil fuel use. In particular, the paper outlines a thermo-economic design methodology taking into account the main variables problem (solar source, system architecture, design constraints, load type and distribution, design criteria and optimization criteria). The innovative element of the methodology is the consideration, among the various costs, of an economic penalty given to the operation of the auxiliary boiler. The results of the application in a particular case are shown in the final section of the paper, showing how it could be possible to increase the value of the solar share, up to 80% with respect to the conventional design method, that often limit this value at 60%

Large N expansion of the 2-matrix model

We present a method, based on loop equations, to compute recursively all the terms in the large $N$ topological expansion of the free energy for the 2-hermitian matrix model. We illustrate the method by computing the first subleading term, i.e. the free energy of a statistical physics model on a discretized torus.Comment: 41 pages, 9 figures eps

Private school quality in Italy

Private school enrolment may lead to worse subsequent performance in further education or in the labour market. If students differ in their ability not only to pay but to take advantage of educational opportunities (“talent” for short), private schools attract a worse pool of students when publicly funded schools are better suited to foster progress by more talented students. In the data we analyze, the impact of observable talent proxies on educational and labour market outcomes is indeed more positive for students who (endogenously) choose to attend public schools than for those who choose to pay for private education

Digital strategies for the valorisation of archival heritage

20th century pre-digital architectural archives are a current topic of interest for scholars involved in historical studies as well as those studying conservation, valorisation and communication. These vast archival heritages could be enhanced by the methodologies, techniques and tools offered by the digital revolution. The present proposal demonstrates this potential through the application of structure from motion techniques to a physical scale model that represents the Turin Horse Racing designed by Carlo Mollino. Moreover, the paper presents a comparison of different software, methodologies and modelling tools and suggests a design for virtual and on-site communication strategies. These strategies fuel new interrelations of knowledge and ideas, through which an archive can become a place of convergence between the real and the virtual

Mixed correlation function and spectral curve for the 2-matrix model

We compute the mixed correlation function in a way which involves only the orthogonal polynomials with degrees close to $n$, (in some sense like the Christoffel Darboux theorem for non-mixed correlation functions). We also derive new representations for the differential systems satisfied by the biorthogonal polynomials, and we find new formulae for the spectral curve. In particular we prove the conjecture of M. Bertola, claiming that the spectral curve is the same curve which appears in the loop equations.Comment: latex, 1 figure, 55 page