3D galaxy clustering with future wide-field surveys: Advantages of a spherical Fourier-Bessel analysis

Upcoming spectroscopic galaxy surveys are extremely promising to help in addressing the major challenges of cosmology, in particular in understanding the nature of the dark universe. The strength of these surveys comes from their unprecedented depth and width. Optimal extraction of their three-dimensional information is of utmost importance to best constrain the properties of the dark universe. Although there is theoretical motivation and novel tools to explore these surveys using the 3D spherical Fourier-Bessel (SFB) power spectrum of galaxy number counts $C_\ell(k,k^\prime)$, most survey optimisations and forecasts are based on the tomographic spherical harmonics power spectrum $C^{(ij)}_\ell$. We performed a new investigation of the information that can be extracted from the tomographic and 3D SFB techniques by comparing the forecast cosmological parameter constraints obtained from a Fisher analysis in the context of planned stage IV wide-field galaxy surveys. The comparison was made possible by careful and coherent treatment of non-linear scales in the two analyses. Nuisance parameters related to a scale- and redshift-dependent galaxy bias were also included for the first time in the computation of both the 3D SFB and tomographic power spectra. Tomographic and 3D SFB methods can recover similar constraints in the absence of systematics. However, constraints from the 3D SFB analysis are less sensitive to unavoidable systematics stemming from a redshift- and scale-dependent galaxy bias. Even for surveys that are optimised with tomography in mind, a 3D SFB analysis is more powerful. In addition, for survey optimisation, the figure of merit for the 3D SFB method increases more rapidly with redshift, especially at higher redshifts, suggesting that the 3D SFB method should be preferred for designing and analysing future wide-field spectroscopic surveys.Comment: 12 pages, 6 Figures. Python package for cosmological forecasts available at https://cosmicpy.github.io . Updated figures. Matches published versio

Using automatic robot programming for space telerobotics

The interpreter of a task level robot programming system called Handey is described. Handey is a system that can recognize, manipulate and assemble polyhedral parts when given only a specification of the goal. To perform an assembly, Handey makes use of a recognition module, a gross motion planner, a grasp planner, a local approach planner and is capable of planning part re-orientation. The possibility of including these modules in a telerobotics work-station is discussed

Spherical 3D Isotropic Wavelets

Future cosmological surveys will provide 3D large scale structure maps with large sky coverage, for which a 3D Spherical Fourier-Bessel (SFB) analysis in spherical coordinates is natural. Wavelets are particularly well-suited to the analysis and denoising of cosmological data, but a spherical 3D isotropic wavelet transform does not currently exist to analyse spherical 3D data. The aim of this paper is to present a new formalism for a spherical 3D isotropic wavelet, i.e. one based on the SFB decomposition of a 3D field and accompany the formalism with a public code to perform wavelet transforms. We describe a new 3D isotropic spherical wavelet decomposition based on the undecimated wavelet transform (UWT) described in Starck et al. 2006. We also present a new fast Discrete Spherical Fourier-Bessel Transform (DSFBT) based on both a discrete Bessel Transform and the HEALPIX angular pixelisation scheme. We test the 3D wavelet transform and as a toy-application, apply a denoising algorithm in wavelet space to the Virgo large box cosmological simulations and find we can successfully remove noise without much loss to the large scale structure. We have described a new spherical 3D isotropic wavelet transform, ideally suited to analyse and denoise future 3D spherical cosmological surveys, which uses a novel Discrete Spherical Fourier-Bessel Transform. We illustrate its potential use for denoising using a toy model. All the algorithms presented in this paper are available for download as a public code called MRS3D at http://jstarck.free.fr/mrs3d.htmlComment: 9 pages + appendices. Public code can be downloaded at http://jstarck.free.fr/mrs3d.html Corrected typos and updated references. Accepted for publication in Astronomy and Astrophysic

Impacto de los residuos de ivermectina en los procesos tecnológicos de la leche y sus derivados

Se evaluó la estabilidad química de los residuos de ivermectina (IVM, fármaco antiparasitario) en leches bovina y ovina. La estabilidad del fármaco se midió mediante cromatografía liquida de alta performance analizando muestras de leche con residuos de IVM antes y después del tratamiento térmico. Además se evaluó, mediante la prueba del yogur y estudios microbiológicos de recuento de bacterias lácticas, el efecto de los residuos sobre la viabilidad de las bacterias ácido lácticas. Los residuos de IVM en leche demostraron ser estables a los tratamientos térmicos utilizados en la industria láctea de pasteurización: baja temperatura/largo tiempo (LTLT 65ºC, 30 min) y alta temperatura/corto tiempo (HTST 75ºC, 15 s). Los procesos de industrialización de la leche basados en la actividad de las bacterias lácticas tampoco fueron afectados por la presencia de residuos de IVM. Las concentraciones evaluadas no modificaron el incremento de la acidez en la prueba del yogur y no disminuyeron los recuentos de bacterias lácticas presentes en muestras de yogures elaborados con residuos del antiparasitario. El impacto de los residuos de fármacos antiparasitarios en los procesos tecnológicos de elaboración de alimentos y en la salud del consumidor a largo plazo debe ser cuidadosamente analizado.Chemical stability of ivermectin residues (IVM, antiparasitic drug) in cattle and sheep milk was evaluated. IVM residues were measured in milk samples before and after heat treatment by high performance liquid chromatography. Additionally, the effect of drug residues on the lactic acid fermentation was assessed by testing the viability and counts of lactic acid bacteria. IVM concentrations in milk were stable after standard procedures used in dairy industry LTLT pasteurization (65°C, 30 min) and HTST (75°C, 15 s). Industrial milk processing based on the activity of lactic acid bacteria was not affected by the presence of IVM residues. IVM concentrations did not affect the increment of acidity nor the number of lactic acid bacteria in yogurt samples. The impact of the residues of antiparasitic drugs in technological processes of food processing and consumer health must be carefully analyzed to avoid long-term consequences

3D Spherical Analysis of Baryon Acoustic Oscillations

Baryon Acoustic Oscillations (BAOs) are oscillatory features in the galaxy power spectrum and are a standard rod to measure the cosmological expansion. These have been studied in Cartesian space (Fourier or real space) or in Spherical Harmonic (SH) space in thin shells. Future wide-field surveys will cover both wide and deep regions of the sky and thus require a simultaneous treatment of the spherical sky and of an extended radial coverage. The Spherical Fourier-Bessel (SFB) decomposition is a natural basis for the analysis of fields in this geometry and facilitates the combination of BAO surveys with other cosmological probes readily described in this basis. We present here a new way to analyse BAOs by studying the BAO wiggles from the SFB power spectrum. In SFB space, the power spectrum generally has both a radial (k) and tangential (l) dependence and so do the BAOs. In the deep survey limit and ignoring evolution, the SFB power spectrum becomes radial and reduces to the Cartesian Fourier power spectrum. In the limit of a thin shell, all the information is contained in the tangential modes described by the 2D SH power spectrum. We find that the radialisation of the SFB power spectrum is still a good approximation even when considering an evolving and biased galaxy field with a finite selection function. This effect can be observed by all-sky surveys with depths comparable to current surveys. We find that the BAOs radialise more rapidly than the full SFB power spectrum. Our results suggest the first peak of the BAOs in SFB space becomes radial out to l ~ 10 for all-sky surveys with the same depth as SDSS or 2dF, and out to l ~ 70 for an all-sky stage IV survey. Subsequent BAO peaks also become radial, but for shallow surveys these may be in the non-linear regime. For modes that have become radial, measurements at different l's are useful in practice to reduce measurement errors.Comment: 6 pages + Appendix. Astro-ph abstract is abridged. Updated with comments from anonymous referee. Corrected axes of Figure 2. Extended discussion of radialisation. Accepted for publication in Astronomy & Astrophysic

PRISM: Recovery of the primordial spectrum from Planck data

The primordial power spectrum describes the initial perturbations that seeded the large-scale structure we observe today. It provides an indirect probe of inflation or other structure-formation mechanisms. In this letter, we recover the primordial power spectrum from the Planck PR1 dataset, using our recently published algorithm PRISM. PRISM is a sparsity-based inversion method, that aims at recovering features in the primordial power spectrum from the empirical power spectrum of the cosmic microwave background (CMB). This ill-posed inverse problem is regularised using a sparsity prior on features in the primordial power spectrum in a wavelet dictionary. Although this non-parametric method does not assume a strong prior on the shape of the primordial power spectrum, it is able to recover both its general shape and localised features. As a results, this approach presents a reliable way of detecting deviations from the currently favoured scale-invariant spectrum. We applied PRISM to 100 simulated Planck data to investigate its performance on Planck-like data. We also tested the algorithm's ability to recover a small localised feature at $k \sim 0.125$ Mpc$^{-1}$, which caused a large dip at $\ell \sim 1800$ in the angular power spectrum. We then applied PRISM to the Planck PR1 power spectrum to recover the primordial power spectrum. We find no significant departures from the fiducial Planck PR1 near scale-invariant primordial power spectrum with $A_s=2.215\times10^{-9}$ and $n_s = 0.9624$.Comment: 4 pages, 2 figures, Accepted in A&A; Updated to match the final accepted versio

Electronic and Magnetic Properties of Febr2

Electronic and magnetic (e-m) properties of FeBr2 have been surprisingly well described as originating from the Fe2+ ions and their fine electronic structure. The fine electronic structure have been evaluated taking into account the spin-orbit (s-o) coupling, crystal-field and inter-site spin-dependent interactions. The required magnetic doublet ground state with an excited singlet at D=2.8 meV results from the trigonal distortion. This effect of the trigonal distortion and a large magnetic moment of iron, of 4.4 mB, can be theoretically derived provided the s-o coupling is correctly taking into account. The obtained good agreement with experimental data indicates on extremaly strong correlations of the six 3d electrons in the Fe2+ ion yielding their full localization and the insulating state. These calculations show that for the meaningful analysis of e-m properties of FeBr2 the spin-orbit coupling is essentially important and that the orbital moment (0.74 mB) is largely unquenched (by the off-cubic trigonal distortion in the presence of the spin-orbit coupling).Comment: 11 pages in RevTex, 5 figure

Impacto de los residuos de ivermectina en los procesos tecnológicos de la leche y sus derivados

Iezzi, S.; Lifschitz, A.; Sallovitz, J.M.; Lanusse, C.; Imperiale, F.: Impacto de los residuos de ivermectina en los procesos tecnológicos de la leche y sus derivados. Rev. vet. 26: 2, 93-98, 201

Contrast sensitivity test and conventional and high frequency audiometry: information beyond that required to prescribe lenses and headsets

In Optometry and in Audiology, the routine tests to prescribe correction lenses and headsets are respectively the visual acuity test (the first chart with letters was developed by Snellen in 1862) and conventional pure tone audiometry (the first audiometer with electrical current was devised by Hartmann in 1878). At present there are psychophysical non invasive tests that, besides evaluating visual and auditory performance globally and even in cases catalogued as normal according to routine tests, supply early information regarding diseases such as diabetes, hypertension, renal failure, cardiovascular problems, etc. Concerning Optometry, one of these tests is the achromatic luminance contrast sensitivity test (introduced by Schade in 1956). Concerning Audiology, one of these tests is high frequency pure tone audiometry (introduced a few decades ago) which yields information relative to pathologies affecting the basal cochlea and complements data resulting from conventional audiometry. These utilities of the contrast sensitivity test and of pure tone audiometry derive from the facts that Fourier components constitute the basis to synthesize stimuli present at the entrance of the visual and auditory systems; that these systems responses depend on frequencies and that the patient's psychophysical state affects frequency processing. The frequency of interest in the former test is the effective spatial frequency (inverse of the angle subtended at the eye by a cycle of a sinusoidal grating and measured in cycles/degree) and, in the latter, the temporal frequency (measured in cycles/sec). Both tests have similar duration and consist in determining the patient's threshold (corresponding to the inverse multiplicative of the contrast or to the inverse additive of the sound intensity level) for each harmonic stimulus present at the system entrance (sinusoidal grating or pure tone sound). In this article the frequencies, standard normality curves and abnormal threshold shifts inherent to the contrast sensitivity test (which for simplicity could be termed "visionmetry") and to pure tone audiometry (also termed auditory sensitivity test) are analyzed with the purpose of contributing to divulge their ability to supply early information associated to pathologies not solely related to the visual and auditory systems respectively. © 2008 American Institute of Physics.Fil:Comastri, S.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Martin, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Simon, J.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina