53 research outputs found
Contractions of low-dimensional nilpotent Jordan algebras
In this paper we classify the laws of three-dimensional and four-dimensional
nilpotent Jordan algebras over the field of complex numbers. We describe the
irreducible components of their algebraic varieties and extend contractions and
deformations among them. In particular, we prove that J2 and J3 are irreducible
and that J4 is the union of the Zariski closures of two rigid Jordan algebras.Comment: 12 pages, 3 figure
Euclid preparation:XXVI. the Euclid Morphology Challenge: Towards structural parameters for billions of galaxies
The various Euclid imaging surveys will become a reference for studies of galaxy morphology by delivering imaging over an unprecedented area of 15 000 square degrees with high spatial resolution. In order to understand the capabilities of measuring morphologies from Euclid-detected galaxies and to help implement measurements in the pipeline of the Organisational Unit MER of the Euclid Science Ground Segment, we have conducted the Euclid Morphology Challenge, which we present in two papers. While the companion paper focusses on the analysis of photometry, this paper assesses the accuracy of the parametric galaxy morphology measurements in imaging predicted from within the Euclid Wide Survey. We evaluate the performance of five state-of-the-art surface-brightness-fitting codes, DeepLeGATo, Galapagos-2, Morfometryka, ProFit and SourceXtractor++, on a sample of about 1.5 million simulated galaxies (350 000 above 5s) resembling reduced observations with the Euclid VIS and NIR instruments. The simulations include analytic Sérsic profiles with one and two components, as well as more realistic galaxies generated with neural networks. We find that, despite some code-specific differences, all methods tend to achieve reliable structural measurements (< 10% scatter on ideal Sérsic simulations) down to an apparent magnitude of about IE = 23 in one component and IE = 21 in two components, which correspond to a signal-to-noise ratio of approximately 1 and 5, respectively. We also show that when tested on non-analytic profiles, the results are typically degraded by a factor of 3, driven by systematics. We conclude that the official Euclid Data Releases will deliver robust structural parameters for at least 400 million galaxies in the Euclid Wide Survey by the end of the mission. We find that a key factor for explaining the different behaviour of the codes at the faint end is the set of adopted priors for the various structural parameters.</p
Boundary Hilbert spaces and trace operators
We discuss the introduction of boundary Hilbert spaces for a class of physical systems for which it is not possible to factor their state spaces as tensor products of Hilbert spaces naturally associated to their boundaries and bulks, respectively. In order to do this we make use of the so called trace operators that play a relevant role in the analysis of PDEs in bounded regions. By taking advantage of these operators and some functorial aspects of the construction of Fock spaces, we will show how to obtain quantum dynamics at the boundaries defined in appropriate Hilbert spaces associated with them.This work has been supported by the Spanish MINECO research grant FIS2014-57387-C3-3-P. Benito A Ju arez-Aubry is supported by CONACYT, project 101712.
Juan Margalef-Bentabol is supported by a "la Caixa" fellowship and a Residencia de
Estudiantes (MINECO) fellowship
Quantization of scalar fields coupled to point masses
We study the Fock quantization of a compound classical system consisting of point masses and a scalar field. We consider the Hamiltonian formulation of the model by using the geometric constraint algorithm of Gotay, Nester and Hinds. By relying on this Hamiltonian description, we characterize in a precise way the real Hilbert space of classical solutions to the equations of motion and use it to rigorously construct the Fock space of the system. We finally discuss the structure of this space, in particular the impossibility of writing it in a natural way as a tensor product of Hilbert spaces associated with the point masses and the field, respectively.We would like to thank J Louko for some enlightening discussions. This work has been supported by the Spanish MINECO research grants FIS2012-34379, FIS2014-57387-C3-3-P and the Consolider-Ingenio 2010 Program CPAN (CSD2007–00042). B Juárez-Aubry is supported by CONACYT, México REF 216072/311506 with additional support from Sistema Estatal de Becas, Veracruz, México. Juan Margalef-Bentabol is supported by a ‘la Caixa’ fellowship
A multi-band AGN-SFG classifier for extragalactic radio surveys using machine learning
Extragalactic radio continuum surveys play an increasingly more important
role in galaxy evolution and cosmology studies. While radio galaxies and radio
quasars dominate at the bright end, star-forming galaxies (SFGs) and
radio-quiet Active Galactic Nuclei (AGNs) are more common at fainter flux
densities. Our aim is to develop a machine learning classifier that can
efficiently and reliably separate AGNs and SFGs in radio continuum surveys. We
perform supervised classification of SFGs vs AGNs using the Light Gradient
Boosting Machine (LGBM) on three LOFAR Deep Fields (Lockman Hole, Bootes and
ELAIS-N1), which benefit from a wide range of high-quality multi-wavelength
data and classification labels derived from extensive spectral energy
distribution (SED) analyses. Our trained model has a precision of 0.92(0.01)
and a recall of 0.87(0.02) for SFGs. For AGNs, the model has slightly worse
performance, with a precision of 0.87(0.02) and recall of 0.78(0.02). These
results demonstrate that our trained model can successfully reproduce the
classification labels derived from detailed SED analysis. The model performance
decreases towards higher redshifts, mainly due to smaller training sample
sizes. To make the classifier more adaptable to other radio galaxy surveys, we
also investigate how our classifier performs with a poorer multi-wavelength
sampling of the SED. In particular, we find that the far-infrared (FIR) and
radio bands are of great importance. We also find that higher S/N in some
photometric bands leads to a significant boost in the model's performance. In
addition to using the 150 MHz radio data, our model can also be used with 1.4
GHz radio data. Converting 1.4 GHz to 150 MHz radio data reduces performance by
about 4% in precision and 3% in recall. The final trained model is publicly
available at https://github.com/Jesper-Karsten/MBASCComment: 14 pages 9 figures Accepted for publication in A&
Organ-specific allergen challenges in airway allergy: Current utilities and future directions
Atopy has been long used as the screening method for airway allergy. Nevertheless, aeroallergens can trigger respiratory symptoms not only in atopic patients (atopic res piratory allergy, ARA), but also in non-atopic subjects (local respiratory allergy, LRA).
Moreover, ARA and LRA can coexist in the same patient, and this clinical scenario has been called dual respiratory allergy (DRA). When the clinical history cannot determine the relevance of sensitizations in ARA patients, nasal, conjunctival or bronchial aller gen challenges (NAC, CAC, and BAC, respectively) should be conducted. Moreover, these tests are required to identify patients with LRA and DRA. The clarification of the allergic triggers of airway diseases has a profound impact on the management
strategies the patients can be offered. Importantly, allergen immunotherapy (AIT) remains as the only disease-modifying intervention for ARA. Recent data indicate that AIT might have a similar effect on LRA patients. Nevertheless, AIT success relies
largely on the correct phenotyping of allergic individuals, and NAC, CAC, and BAC are very helpful tools in this regard. In this review, we will summarize the main indications and methodology of CAC, NAC, and BAC. Importantly, the clinical implementation
of these tests might translate into precision medicine approaches and better health outcomes for patients with airway allergy.Consejería de Salud, Junta de Andalucía, Grant/Award Number: P20_00405; Instituto de Salud Carlos III, Grant/Award
Number: PI20/01715, RD21/0002/0008, CM21/00262, CM20/00160, JR22/00048 and JR19/00029.
Funding for open access charge: Universidad de Málaga / CBUA
Euclid preparation. XXVI. The Euclid Morphology Challenge: Towards structural parameters for billions of galaxies
The various Euclid imaging surveys will become a reference for studies of galaxy morphology by delivering imaging over an unprecedented area of 15 000 square degrees with high spatial resolution. In order to understand the capabilities of measuring morphologies from Euclid-detected galaxies and to help implement measurements in the pipeline of the Organisational Unit MER of the Euclid Science Ground Segment, we have conducted the Euclid Morphology Challenge, which we present in two papers. While the companion paper focusses on the analysis of photometry, this paper assesses the accuracy of the parametric galaxy morphology measurements in imaging predicted from within the Euclid Wide Survey. We evaluate the performance of five state-of-the-art surface-brightness-fitting codes, , , , and , on a sample of about 1.5 million simulated galaxies (350 000 above 5σ) resembling reduced observations with the Euclid VIS and NIR instruments. The simulations include analytic Sérsic profiles with one and two components, as well as more realistic galaxies generated with neural networks. We find that, despite some code-specific differences, all methods tend to achieve reliable structural measurements (< 10% scatter on ideal Sérsic simulations) down to an apparent magnitude of about I = 23 in one component and I = 21 in two components, which correspond to a signal-to-noise ratio of approximately 1 and 5, respectively. We also show that when tested on non-analytic profiles, the results are typically degraded by a factor of 3, driven by systematics. We conclude that the official Euclid Data Releases will deliver robust structural parameters for at least 400 million galaxies in the Euclid Wide Survey by the end of the mission. We find that a key factor for explaining the different behaviour of the codes at the faint end is the set of adopted priors for the various structural parameters
Euclid preparation: XXVI. the Euclid Morphology Challenge: Towards structural parameters for billions of galaxies
The various Euclid imaging surveys will become a reference for studies of galaxy morphology by delivering imaging over an unprecedented area of 15 000 square degrees with high spatial resolution. In order to understand the capabilities of measuring morphologies from Euclid-detected galaxies and to help implement measurements in the pipeline of the Organisational Unit MER of the Euclid Science Ground Segment, we have conducted the Euclid Morphology Challenge, which we present in two papers. While the companion paper focusses on the analysis of photometry, this paper assesses the accuracy of the parametric galaxy morphology measurements in imaging predicted from within the Euclid Wide Survey. We evaluate the performance of five state-of-the-art surface-brightness-fitting codes, DeepLeGATo, Galapagos-2, Morfometryka, ProFit and SourceXtractor++, on a sample of about 1.5 million simulated galaxies (350 000 above 5σ) resembling reduced observations with the Euclid VIS and NIR instruments. The simulations include analytic Sérsic profiles with one and two components, as well as more realistic galaxies generated with neural networks. We find that, despite some code-specific differences, all methods tend to achieve reliable structural measurements (< 10% scatter on ideal Sérsic simulations) down to an apparent magnitude of about IE = 23 in one component and IE = 21 in two components, which correspond to a signal-to-noise ratio of approximately 1 and 5, respectively. We also show that when tested on non-analytic profiles, the results are typically degraded by a factor of 3, driven by systematics. We conclude that the official Euclid Data Releases will deliver robust structural parameters for at least 400 million galaxies in the Euclid Wide Survey by the end of the mission. We find that a key factor for explaining the different behaviour of the codes at the faint end is the set of adopted priors for the various structural parameters
Euclid preparation XXVI. The Euclid Morphology Challenge. Towards structural parameters for billions of galaxies
The various Euclid imaging surveys will become a reference for studies of
galaxy morphology by delivering imaging over an unprecedented area of 15 000
square degrees with high spatial resolution. In order to understand the
capabilities of measuring morphologies from Euclid-detected galaxies and to
help implement measurements in the pipeline, we have conducted the Euclid
Morphology Challenge, which we present in two papers. While the companion paper
by Merlin et al. focuses on the analysis of photometry, this paper assesses the
accuracy of the parametric galaxy morphology measurements in imaging predicted
from within the Euclid Wide Survey. We evaluate the performance of five
state-of-the-art surface-brightness-fitting codes DeepLeGATo, Galapagos-2,
Morfometryka, Profit and SourceXtractor++ on a sample of about 1.5 million
simulated galaxies resembling reduced observations with the Euclid VIS and NIR
instruments. The simulations include analytic S\'ersic profiles with one and
two components, as well as more realistic galaxies generated with neural
networks. We find that, despite some code-specific differences, all methods
tend to achieve reliable structural measurements (10% scatter on ideal S\'ersic
simulations) down to an apparent magnitude of about 23 in one component and 21
in two components, which correspond to a signal-to-noise ratio of approximately
1 and 5 respectively. We also show that when tested on non-analytic profiles,
the results are typically degraded by a factor of 3, driven by systematics. We
conclude that the Euclid official Data Releases will deliver robust structural
parameters for at least 400 million galaxies in the Euclid Wide Survey by the
end of the mission. We find that a key factor for explaining the different
behaviour of the codes at the faint end is the set of adopted priors for the
various structural parameters.Comment: Accepted by A&A. 30 pages, 23+6 figures, Euclid pre-launch key paper.
Companion paper: Euclid Collaboration XXV: Merlin et al. 2022 Minor
corrections after journal revie
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