| Records |
| Author |
Caroca, R.; Kondrashuk, I.; Merino, N.; Nadal, F. |
| Title |
Bianchi spaces and their three-dimensional isometries as S-expansions of two-dimensional isometries |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of Physics A |
Abbreviated Journal  |
J. Phys. A |
| Volume |
46 |
Issue |
22 |
Pages |
225201 - 24pp |
| Keywords |
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| Abstract |
In this paper we show that certain three-dimensional isometry algebras, specifically those of type I, II, III and V (according to Bianchi's classification), can be obtained as expansions of the isometries in two dimensions. In particular, we use the so-called S-expansionmethod, which makes use of the finite Abelian semigroups, because it is the most general procedure known until now. Also, it is explicitly shown why it is impossible to obtain the algebras of type IV, VI-IX as expansions from the isometry algebras in two dimensions. All the results are checked with computer programs. This procedure shows that the problem of how to relate, by an expansion, two Lie algebras of different dimensions can be entirely solved. In particular, the procedure can be generalized to higher dimensions, which could be useful for diverse physical applications, as we discuss in our conclusions. |
| Address |
Univ Catolica Santisima, Dept Matemat & Fis Aplicadas, Concepcion, Chile, Email: nelson.merino@ucv.cl |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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| Language |
English |
Summary Language |
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Series Issue |
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Edition |
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| ISSN |
1751-8113 |
ISBN |
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Expedition |
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Conference |
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| Notes |
WOS:000319044900004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1457 |
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| Author |
Andrianopoli, L.; Merino, N.; Nadal, F.; Trigiante, M. |
| Title |
General properties of the expansion methods of Lie algebras |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of Physics A |
Abbreviated Journal |
J. Phys. A |
| Volume |
46 |
Issue |
36 |
Pages |
365204 - 33pp |
| Keywords |
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| Abstract |
The study of the relation between Lie algebras and groups, and especially the derivation of new algebras from them, is a problem of great interest in mathematics and physics, because finding a new Lie group from an already known one also means that a new physical theory can be obtained from a known one. One of the procedures that allow us to do so is called expansion of Lie algebras, and has been recently used in different physical applications-particularly in gauge theories of gravity. Here we report on further developments of this method, required to understand in a deeper way their consequences in physical theories. We have found theorems related to the preservation of some properties of the algebras under expansions that can be used as criteria and, more specifically, as necessary conditions to know if two arbitrary Lie algebras can be related by some expansion mechanism. Formal aspects, such as the Cartan decomposition of the expanded algebras, are also discussed. Finally, an instructive example that allows us to check explicitly all our theoretical results is also provided. |
| Address |
[Andrianopoli, L.; Nadal, F.; Trigiante, M.] Politecn Torino, Dipartimento Sci Applicata & Tecnol DISAT, I-10129 Turin, Italy, Email: nelson.merino@ucv.cl |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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| Language |
English |
Summary Language |
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Series Issue |
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Edition |
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| ISSN |
1751-8113 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000323421800008 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1560 |
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| Author |
de Azcarraga, J.A.; Izquierdo, J.M. |
| Title |
k-Leibniz algebras from lower order ones: From Lie triple to Lie l-ple systems |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of Mathematical Physics |
Abbreviated Journal |
J. Math. Phys. |
| Volume |
54 |
Issue |
9 |
Pages |
093510 - 14pp |
| Keywords |
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| Abstract |
Two types of higher order Lie l-ple systems are introduced in this paper. They are defined by brackets with l > 3 arguments satisfying certain conditions, and generalize the well-known Lie triple systems. One of the generalizations uses a construction that allows us to associate a (2n – 3)-Leibniz algebra pound with a metric n-Leibniz algebra () pound over tilde by using a 2(n – 1)-linear Kasymov trace form for () pound over tilde. Some specific types of k-Leibniz algebras, relevant in the construction, are introduced as well. Both higher order Lie l-ple generalizations reduce to the standard Lie triple systems for l = 3. |
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Edition |
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| ISSN |
0022-2488 |
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Medium |
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Expedition |
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Conference |
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| Notes |
WOS:000325407300032 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
1618 |
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| Author |
KM3NeT Collaboration (Adrian-Martinez, S. et al); Aguilar, J.A.; Bigongiari, C.; Calvo Diaz-Aldagalan, D.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Mangano, S.; Real, D.; Salesa, F.; Toscano, S.; Urbano, F.; Yepes, H.; Zornoza, J.D.; Zuñiga, J. |
| Title |
Expansion cone for the 3-inch PMTs of the KM3NeT optical modules |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
8 |
Issue |
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Pages |
T03006 - 20pp |
| Keywords |
Optical detector readout concepts; Instrument optimisation; Cherenkov detectors; Large detector systems for particle and astroparticle physics |
| Abstract |
Detection of high-energy neutrinos from distant astrophysical sources will open a new window on the Universe. The detection principle exploits the measurement of Cherenkov light emitted by charged particles resulting from neutrino interactions in the matter containing the telescope. A novel multi-PMT digital optical module (DOM) was developed to contain 31 3-inch photomultiplier tubes (PMTs). In order to maximize the detector sensitivity, each PMT will be surrounded by an expansion cone which collects photons that would otherwise miss the photocathode. Results for various angles of incidence with respect to the PMT surface indicate an increase in collection efficiency by 30% on average for angles up to 45 degrees with respect to the perpendicular. Ray-tracing calculations could reproduce the measurements, allowing to estimate an increase in the overall photocathode sensitivity, integrated over all angles of incidence, by 27% (for a single PMT). Prototype DOMs, being built by the KM3NeT consortium, will be equipped with these expansion cones. |
| Address |
Univ Aberdeen, Aberdeen, Scotland, Email: o.kavatsyuk@rug.nl |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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| Language |
English |
Summary Language |
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Series Title |
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Series Issue |
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Edition |
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| ISSN |
1748-0221 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000316990700051 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1391 |
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| Author |
Pierre Auger Collaboration (Abreu, P. et al); Pastor, S. |
| Title |
Techniques for measuring aerosol attenuation using the Central Laser Facility at the Pierre Auger Observatory |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
8 |
Issue |
|
Pages |
P04009 - 28pp |
| Keywords |
Data analysis; Large detector systems for particle and astroparticle physics; Detector alignment and calibration methods (lasers, sources, particle-beams) |
| Abstract |
The Pierre Auger Observatory in Malargue, Argentina, is designed to study the properties of ultra-high energy cosmic rays with energies above 10(18) eV. It is a hybrid facility that employs a Fluorescence Detector to perform nearly calorimetric measurements of Extensive Air Shower energies. To obtain reliable calorimetric information from the FD, the atmospheric conditions at the observatory need to be continuously monitored during data acquisition. In particular, light attenuation due to aerosols is an important atmospheric correction. The aerosol concentration is highly variable, so that the aerosol attenuation needs to be evaluated hourly. We use light from the Central Laser Facility, located near the center of the observatory site, having an optical signature comparable to that of the highest energy showers detected by the FD. This paper presents two procedures developed to retrieve the aerosol attenuation of fluorescence light from CLF laser shots. Cross checks between the two methods demonstrate that results from both analyses are compatible, and that the uncertainties are well understood. The measurements of the aerosol attenuation provided by the two procedures are currently used at the Pierre Auger Observatory to reconstruct air shower data. |
| Address |
Ctr Atom Bariloche, San Carlos De Bariloche, Rio Negro, Argentina |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1748-0221 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000317462400016 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1413 |
| Permanent link to this record |
