1,432 research outputs found
Lepton Mixing from Delta (3 n^2) and Delta (6 n^2) and CP
We perform a detailed study of lepton mixing patterns arising from a scenario
with three Majorana neutrinos in which a discrete flavor group Gf=Delta (3 n^2)
or Gf=Delta(6 n^2) and a CP symmetry are broken to residual symmetries Ge=Z3
and Gnu=Z2 x CP in the charged lepton and neutrino sectors, respectively. While
we consider all possible Z3 and Z2 generating elements, we focus on a certain
set of CP transformations. The resulting lepton mixing depends on group
theoretical indices and one continuous parameter. In order to study the mixing
patterns comprehensively for all admitted Ge and Gnu, it is sufficient to
discuss only three types of combinations. One of them requires as flavor group
Delta (6 n^2). Two types of combinations lead to mixing patterns with a
trimaximal column, while the third one allows for a much richer structure. For
the first type of combinations the Dirac as well as one Majorana phase are
trivial, whereas the other two ones predict in general all CP phases to be
non-trivial and also non-maximal. Already for small values of the index n of
the group, n <= 11, experimental data on lepton mixing can be accommodated well
for particular choices of the parameters of the theory. We also comment on the
relation of the used CP transformations to the automorphisms of Delta (3 n^2)
and Delta (6 n^2).Comment: 60 pages, 12 tables and 10 figures. v2: typos corrected, references
updated, some minor improvement of the text, matches version accepted for
publication in Nuclear Physics
Colour and stellar population gradients in galaxies
We discuss the colour, age and metallicity gradients in a wide sample of
local SDSS early- and late-type galaxies. From the fitting of stellar
population models we find that metallicity is the main driver of colour
gradients and the age in the central regions is a dominant parameter which
rules the scatter in both metallicity and age gradients. We find a consistency
with independent observations and a set of simulations. From the comparison
with simulations and theoretical considerations we are able to depict a general
picture of a formation scenario.Comment: 4 pages, 4 figures. Proceedings of 54th Congresso Nazionale della
SAIt, Napoli 4-7 May 201
Complexity of Approximate Query Answering under Inconsistency in Datalog+/-
This is the author accepted manuscript. The final version is available from the publisher via the link in this recordSeveral semantics have been proposed to query inconsistent ontological
knowledge bases, including the intersection of repairs and the intersection of closed
repairs as two approximate inconsistency-tolerant semantics. In this paper, we
analyze the complexity of conjunctive query answering under these two semantics
for a wide range of Datalog± languages. We consider both the standard setting,
where errors may only be in the database, and the generalized setting, where also
the rules of a Datalog± knowledge base may be erroneous.This work was supported by The Alan Turing Institute under the
UK EPSRC grant EP/N510129/1, and by the EPSRC grants EP/R013667/1, EP/L012138/1,
and EP/M025268/1
Complexity of Approximate Query Answering under Inconsistency in Datalog+/-
This is the author accepted manuscript. The final version is freely available from IJCAI via the link in this recordSeveral semantics have been proposed to query inconsistent
ontological knowledge bases, including
the intersection of repairs and the intersection of
closed repairs as two approximate inconsistencytolerant
semantics. In this paper, we analyze the
complexity of conjunctive query answering under
these two semantics for a wide range of Datalog±
languages. We consider both the standard setting,
where errors may only be in the database, and the
generalized setting, where also the rules of a Datalog±
knowledge base may be erroneous.This work was supported by The Alan Turing Institute under
the UK EPSRC grant EP/N510129/1, and by the EPSRC
grants EP/R013667/1, EP/L012138/1, and EP/M025268/1
Any leftovers from a discarded prediction? Evidence from eye-movements during sentence comprehension
Published online: 23 May 2019.We investigated how listeners use gender-marked adjectives to adjust lexical predictions during
sentence comprehension. Participants listened to sentence fragments in Spanish (e.g. “The witch
flew to the village on her…”) that created expectation for a specific noun (broomstickfem), and
were completed by an adjective and a noun. The adjective either agreed (newfem), disagreed
(newmasc), or was neutral (bigfem/masc) with respect to the expected noun’s gender. Using the
visual-world paradigm, we monitored looks toward images of the expected noun versus an
alternative of the opposite gender (helicoptermasc). While listening to the initial fragment,
participants looked more towards the expected noun. Once the adjective was heard, looks
shifted toward the noun that matched the adjective’s gender. Finally, upon hearing the noun,
looks were affected by both previous context and adjective gender. We conclude that
predictions are updated online based on gender cues, but sentence context still affects
integration of the expected noun.This work was partially supported by the Ministerio de Economía,
Industria y Competitividad, Gobierno de España, the
Agencia Estatal de Investigación and the Fondo Europeo de
Desarrollo Regional (grant PSI2015-65694-P, “Severo Ochoa”
programme SEV-2015-490 for Centres of Excellence in R&D),
and by the Eusko Jaurlaritza (grant PI_2016_1_0014). Further
support derived from the AThEME project funded by the European
Commission Seventh Framework Programme, the ERC-
2011-ADG-295362 from the European Research Council. This
project was also supported by the Ministerio de Economía,
Industria y Competitividad, Gobierno de España through the
convocatoria 2016 Subprograma Estatal Ayudas para contratos
para la Formación Posdoctoral 2016, Programa Estatal de Promoción
del Talento y su Empleabilidad del Plan Estatal de
Investigación Científica y Técnica y de Innovación 2013–2016,
reference FJCI-2016-28019
CP violation in the lepton sector and implications for leptogenesis
We review the current status of the data on neutrino masses and lepton mixing and the prospects for measuring the CP-violating phases in the lepton sector. The possible connection between low energy CP violation encoded in the Dirac and Majorana phases of the Pontecorvo-Maki-Nakagawa-Sakata mixing matrix and successful leptogenesis is emphasized in the context of seesaw extensions of the Standard Model with a flavor symmetry Gf (and CP symmetry)
Workaholism, intensive smartphone use, and the sleep-wake cycle: A multiple mediation analysis
Recent contributions have reported sleep disorders as one of the health impairment outcomes of workaholism. A possible factor affecting the sleep-wake cycle might be the intensive use of smartphones. The current study aimed to explore the role of intensive smartphone use in the relationship between workaholism and the sleep-wake cycle. Two serial multiple mediation models were tested on a sample of 418 employees, who filled self-report questionnaires measuring workaholism, use of smartphones, sleep quality and daytime sleepiness, using conditional process analysis for testing direct and indirect effects. Results supported our hypotheses regarding two serial multiple mediation models-that intensive smartphone use and poor sleep quality mediated the relationship between workaholism and daytime sleepiness, and that smartphone use and daytime sleepiness mediated the relationship between workaholism and poor quality of sleep. Although the use of a cross-sectional design and the snowball technique for collecting data can be considered as possible limitations, the current study is one of the first to document the potential detrimental role of the intensive smartphone use on the workaholism-sleep disorders relationship
The modified Newtonian dynamics Fundamental Plane
Modified Newtonian dynamics (MOND) has been shown to be able to fit spiral galaxy rotation curves as well as giving a theoretical foundation for empirically determined scaling relations, such as the Tully-Fisher law, without the need for a dark matter halo. As a complementary analysis, one should investigate whether MOND can also reproduce the dynamics of early-type galaxies (ETGs) without dark matter. As a first step, we here show that MOND can indeed fit the observed central velocity dispersion σ0 of a large sample of ETGs assuming a simple MOND interpolating functions and constant anisotropy. We also show that, under some assumptions on the luminosity dependence of the Sérsic n parameter and the stellar mass-to-light ratio (M/L), MOND predicts a Fundamental Plane for ETGs: a loglinear relation among the effective radius Reff, σ0 and the mean effective intensity 〈Ie〉. However, we predict a tilt between the observed and the MOND Fundamental Plane
Colour and stellar population gradients in galaxies: correlation with mass
We analyse the colour gradients (CGs) of ∼ 50 000 nearby Sloan Digital Sky Survey galaxies estimated by their photometrical parameters (Sérsic index, total magnitude and effective radius). From synthetic spectral models based on a simplified star formation recipe, we derive the mean spectral properties and explain the observed radial trends of the colour as gradients of the stellar population age and metallicity. CGs have been correlated with colour, luminosity, size, velocity dispersion and stellar mass. Distinct behaviours are found for early- and late-type galaxies (ETGs and LTGs), pointing to slightly different physical processes at work in different morphological types and at different mass scales. In particular, the most massive ETGs (M*≳ 1011 M☉) have shallow (even flat) CGs in correspondence of shallow (negative) metallicity gradients. In the stellar mass range (1010.3− 1010.5) ≲M*≲ 1011 M☉, the metallicity gradients reach their minimum of ∼ − 0.5 dex−1. At M*∼ 1010.3− 1010.5 M☉, colour and metallicity gradient slopes suddenly change. They turn out to anticorrelate with the mass, becoming highly positive at the very low masses, the transition from negative to positive occurring at M*∼ 109−9.5 M☉. These correlations are mirrored by similar trends of CGs with the effective radius and the velocity dispersion. We have also found that age gradients anticorrelate with metallicity gradients, as predicted by hierarchical cosmological simulations for ETGs. On the other side, LTGs have colour and metallicity gradients which systematically decrease with mass (and are always more negative than in ETGs), consistently with the expectation from gas infall and supernovae feedback scenarios. Metallicity is found to be the main driver of the trend of CGs, especially for LTGs, but age gradients are not negligible and seem to play a significant role too. Owing to the large data set, we have been able to highlight that older galaxies have systematically shallower age and metallicity gradients than younger ones. The emerging picture is qualitatively consistent with the predictions from hydrodynamical and chemodynamical simulations. In particular, our results for high-mass galaxies are in perfect agreement with predictions based on the merging scenario, while the evolution of LTGs and younger and less massive ETGs seems to be mainly driven by infall and supernovae feedbac
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