8,721 research outputs found
On the Nature of the Strong Emission-Line Galaxies in Cluster Cl 0024+1654: Are Some the Progenitors of Low Mass Spheroidals?
We present new size, line ratio, and velocity width measurements for six
strong emission-line galaxies in the galaxy cluster, Cl 0024+1654, at redshift
z~0.4. The velocity widths from Keck spectra are all narrow (30<sigma<120
km/s), with three profiles showing double peaks. Four galaxies have low masses
(M<10^{10} Mo). Whereas three galaxies were previously reported to be possible
AGNs, none exhibit AGN-like emission line ratios or velocity widths. Two or
three appear as very blue spirals with the remainder more akin to luminous H-II
galaxies undergoing a strong burst of star formation. We propose that after the
burst subsides, these galaxies will transform into quiescent dwarfs, and are
thus progenitors of some cluster spheroidals (We adopt the nomenclature
suggested by Kormendy & Bender (1994), i.e., low-density, dwarf ellipsoidal
galaxies like NGC 205 are called `spheroidals' instead of `dwarf ellipticals')
seen today.Comment: 14 pages + 2 figures + 1 table, LaTeX, Acc. for publ. in ApJL also
  available at http://www.ucolick.org/~deep/papers/papers.htm
On the use of preference-based evolutionary multi-objective optimization for solving a credibilistic portfolio selection model
The portfolio selection problem tries to identify the assets to allocate the capital, and the proportion to be devoted to each asset, for maximizing the returns at the minimum risk. By nature, this is a multi-objective optimization problem. In this work, we propose a three-objective model for portfolio selection, in which the uncertainty of the portfolio returns is modelled by means of LR-power fuzzy variables. We consider as criteria the credibilistic expected return (to be maxi-
mized), the below-mean absolute semi-deviation as a risk measure (to be minimized), and a loss function which evaluates the credibility of achieving a non-positive return (to be minimized). The uncorrelation among the risk and loss measures concludes that they provide different information.
Budget, cardinality, and diversification constraints are considered. To generate non-dominated portfolios fitting the investor' expectations, preference-based evolutionary algorithms are applied. The preferences are given by aspiration values to be attained by the objectives and profiles representing aggressive, cautious, and conservative investors are analysed. The results for data of the IBEX35 show that portfolios improving the preferences are found in the cautious and aggressive cases, while portfolios with objective values as close as possible to the expectations are obtained in the conservative case. In the generation process, the credibilistic loss has played an important role to and diversified portfolios.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Scaling of Local Slopes, Conservation Laws and Anomalous Roughening in Surface Growth
We argue that symmetries and conservation laws greatly restrict the form of
the terms entering the long wavelength description of growth models exhibiting
anomalous roughening. This is exploited to show by dynamic renormalization
group arguments that intrinsic anomalous roughening cannot occur in local
growth models. However some conserved dynamics may display super-roughening if
a given type of terms are present.Comment: To appear in Phys. Rev. Lett., 4 pages in RevTeX style, no fig
Deformation of canonical morphisms and the moduli of surfaces of general type
In this article we study the deformation of finite maps and show how to use
this deformation theory to construct varieties with given invariants in a
projective space. Among other things, we prove a criterion that determines when
a finite map can be deformed to a one--to--one map. We use this criterion to
construct new simple canonical surfaces with different  and . Our
general results enable us to describe some new components of the moduli of
surfaces of general type. We also find infinitely many moduli spaces  having one component whose general point corresponds to a
canonically embedded surface and another component whose general point
corresponds to a surface whose canonical map is a degree 2 morphism.Comment: 32 pages. Final version with some simplifications and clarifications
  in the exposition. To appear in Invent. Math. (the final publication is
  available at springerlink.com
Are There Local Analogs of Lyman Break Galaxies?
To make direct comparisons in the rest-far-ultraviolet between LBGs at z~3
and more local star-forming galaxies, we use HST/STIS to image a set of 12
nearby (z<0.05) HII galaxies in the FUV and a set of 14 luminous compact blue
galaxies (LCBGs) at moderate redshift (z~0.5) in the NUV, corresponding to the
rest-FUV. We then subject both sets of galaxy images and those of LBGs at z~3
to the same morphological and structural analysis. We find many qualitative and
quantitative similarities between the rest-FUV characteristics of distant LBGs
and of the more nearby starburst samples, including general morphologies,
sizes, asymmetries, and concentrations. Along with some kinematic similarities,
this implies that nearby HII galaxies and LCBGs may be reasonable local analogs
of distant Lyman break galaxies.Comment: 4 pages, 4 figures. To appear in "Starbursts: from 30 Doradus to
  Lyman Break Galaxies" 2005, eds. R. de Grijs and R. M. Gonzalez Delgado
  (Kluwer
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