The dependence of halo bias on age, concentration and spin

Halo bias is the main link between the matter distribution and dark matter halos. In its simplest form, halo bias is determined by halo mass, but there are known additional dependencies on other halo properties which are of consequence for accurate modeling of galaxy clustering. Here we present the most precise measurement of these secondary-bias dependencies on halo age, concentration, and spin, for a wide range of halo masses spanning from 10$^{10.7}$ to 10$^{14.7}$ $h^{-1}$ M$_{\odot}$. At the high-mass end, we find no strong evidence of assembly bias for masses above M$_{vir}$ $\sim10^{14}$ $h^{-1}$ M$_{\odot}$. Secondary bias exists, however, for halo concentration and spin, up to cluster-size halos, in agreement with previous findings. For halo spin, we report, for the first time, two different regimes: above M$_{vir}\sim$10$^{11.5}$ $h^{-1}$ M$_{\odot}$, halos with larger values of spin have larger bias, at fixed mass, with the effect reaching almost a factor 2. This trend reverses below this characteristic mass. In addition to these results, we test, for the first time, the performance of a multi-tracer method for the determination of the relative bias between different subsets of halos. We show that this method increases significantly the signal-to-noise of the secondary-bias measurement as compared to a traditional approach. This analysis serves as the basis for follow-up applications of our multi-tracer method to real data.Comment: 11 pages, 6 figures, submitted to MNRA

Viscosity of Cuban molasses

A kubai cukorgyárakból származó nagyszámú curkornádmelasz minta vizsgálata alapján megállapítható, hogy a melaszok a 40 —80 °C tartományban pszeudoplasztikus testként jellemezhetők. A „Rheotest” rotációs viszkoziméteren mért adatok és a kolloid anyag tartalom között nem sikerült egyértelmű összefüggést találni. A melaszok viszkozitását alapvetően a hőmérséklet és a szárazanyag tartalom befolyásolja

The galaxy formation origin of the lensing is low problem

Recent analyses show that $\Lambda$CDM-based models optimised to reproduce the clustering of massive galaxies overestimate their gravitational lensing by about 30\%, the so-called lensing is low problem. Using a state-of-the-art hydrodynamical simulation, we show that this discrepancy reflects shortcomings in standard galaxy-halo connection models rather than tensions within the $\Lambda$CDM paradigm itself. Specifically, this problem results from ignoring a variety of galaxy formation effects, including assembly bias, segregation of satellite galaxies relative to dark matter, and baryonic effects on the matter distribution. All these effects contribute towards overestimating gravitational lensing and, when combined, explain the amplitude and scale dependence of the lensing is low problem. We conclude that simplistic galaxy-halo connection models are inadequate to interpret clustering and lensing simultaneously, and that it is crucial to employ more sophisticated models for the upcoming generation of large-scale surveys.Comment: 16 pages, 12 figures, accepted by MNRA

La mezcla de marketing y el posicionamiento de la empresa de transporte Turismo Corvival, Chimbote – 2019

La presente investigación titulada “La mezcla de marketing y el posicionamiento de la empresa de transporte Turismo Corvival, Chimbote – 2019”, tuvo como objetivo determinar la relación de la mezcla de marketing y el posicionamiento de la empresa de transporte Turismo Corvival, Chimbote – 2019. La investigación tuvo un enfoque cuantitativo, de tipo no experimental – transversal, y con diseño descriptivo-correlacional. Con respecto a la población en el estudio se tomó a un total de 1154 clientes que la empresa de transportes atendió entre los años 2018-2019, mientras que como muestra se determinó un total de 288 clientes a encuestar. Para el proceso de recolección se desarrollaron dos cuestionarios como instrumentos de investigación, donde el cuestionario de mezcla de marketing estuvo conformado por 40 ítems y el de posicionamiento tuvo 31 ítems. La conclusión general de la investigación, se determinó por medio de la prueba estadística de relación Rho Spearman, donde se estableció un coeficiente de 0.829, y una significancia bilateral de 0,000 que es menor a 5%. Por lo tanto, es posible afirmar que la mezcla de marketing y el posicionamiento de la empresa de transportes Turismo Corvival tienen una correlación positiva alta, acreditándose así que las variables de estudio mantienen una relación directamente proporcional. Se argumenta por lo tanto que el progreso o mejora de la mezcla de marketing puede provocar un incentivo considerable en el aumento de posicionamiento de la empresa de transportes

Factores asociados a fracaso terapéutico tras quimioterapia primaria y la relación índice neutrófilo/linfocito como factor pronóstico en pacientes mayores de 18 años con diagnóstico de tumor de células germinales primario testicular en el servicio de oncología del Hospital Nacional Edgardo Rebagliati Martins en el periodo enero 2017- enero 2020

En el Perú el año 2018 fueron registrados 792 casos nuevos de cáncer testicular correspondiente al 1.32% del total de canceres registrados ese año. Con 110 muertes reportadas, siendo el 0.36% de muertes total por cáncer el mismo año y prevalencia de 2759 casos en el periodo de 5 años 1. En varones de 20 a 35 años son los tumores sólidos más frecuentes. Existen tres picos de incidencia: en la infancia, entre los 25 a 40 años y alrededor de los 60 años 2. Por lo que, dicha neoplasia adquiere una importancia especial debido a que afecta en un periodo de máxima actividad, tanto física, intelectual y laboral, y es un ejemplo de enfermedad oncológica con altas tasas de curación. A lo largo de los años la supervivencia global estimada ha ido incrementándose progresivamente, desde 62% a los 5 años en la década de los 50, y en la actualidad alrededor del 95% en los estadíos más avanzados 3. Durante mi formación en la especialidad observé recaídas prontas, y en otros, falla en la respuesta a la quimioterapia primaria iniciada, lo que me motiva a presentar este proyect

Influence of liquid-to-biogas ratio and alkalinity on the biogas upgrading performance in a demo scale algal-bacterial photobioreactor

The influence of the liquid-to-biogas ratio (L/G) and alkalinity on methane quality was evaluated in a 11.7 m3 outdoors horizontal semi-closed tubular photobioreactor interconnected to a 45-L absorption column (AC). CO2 concentrations in the upgraded methane ranged from <0.1 to 9.6% at L/G of 2.0 and 0.5, respectively, with maximum CH4 concentrations of 89.7% at a L/G of 1.0. Moreover, an enhanced CO2 removal (mediating a decrease in CO2 concentration from 9.6 to 1.2%) and therefore higher CH4 contents (increasing from 88.0 to 93.2%) were observed when increasing the alkalinity of the AC cultivation broth from 42 ± 1 mg L−1 to 996 ± 42 mg L−1. H2S was completely removed regardless of the L/G or the alkalinity in AC. The continuous operation of the photobioreactor with optimized operating parameters resulted in contents of CO2 (<0.1%–1.4%), H2S (<0.7 mg m−3) and CH4 (94.1%–98.8%) complying with international regulations for methane injection into natural gas grids.Peer ReviewedPostprint (published version

Consistent and simultaneous modelling of galaxy clustering and galaxy-galaxy lensing with Subhalo Abundance Matching

The spatial distribution of galaxies and their gravitational lensing signal offer complementary tests of galaxy formation physics and cosmology. However, their synergy can only be fully exploited if both probes are modelled accurately and consistently. In this paper, we demonstrate that this can be achieved using an extension of Subhalo Abundance Matching, dubbed SHAMe. Specifically, we use mock catalogues built from the TNG300 hydrodynamical simulation to show that SHAMe can simultaneously model the multipoles of the redshift-space galaxy correlation function and galaxy-galaxy lensing, without noticeable bias within the statistical sampling uncertainties of a SDSS volume and on scales r = [0.6-30] Mpc/h. Modelling the baryonic processes in galaxy-galaxy lensing with a baryonification scheme allows SHAMe's range of validity to be extended to r = [0.1-30] Mpc/h. Remarkably, our model achieves this level of precision with just five free parameters beyond those describing the baryonification model. At fixed cosmology, we find that galaxy-galaxy lensing provides a general consistency test but little additional information on galaxy modelling parameters beyond that encoded in the redshift-space multipoles. It does, however, improve constraints if only the projected correlation function is available, as in surveys with only photometric redshifts. We expect SHAMe to have a higher fidelity across a wider range of scales than more traditional methods such as Halo Occupation Distribution modelling. Thus it should provide a significantly more powerful and more robust tool for analysing next-generation large-scale surveys.Comment: 14 pages, 7 figures. Submitted to MNRA

The galaxy size - halo mass scaling relations and clustering properties of central and satellite galaxies

In this work, we combine size and stellar mass measurements from the Sloan Digital Sky Server (SDSS) with the group finder algorithm of Rodriguez \& Merch\'an in order to determine the stellar and halo mass -- size relations of central and satellite galaxies separately. We show that, while central and satellite galaxies display similar stellar mass -- size relations, their halo mass -- size relations differ significantly. As expected, more massive haloes tend to host larger central galaxies. However, the size of satellite galaxies depends only slightly on halo virial mass. We show that these results are compatible with a remarkably simple model in which the size of central and satellite galaxies scales as the cubic root of their host halo mass, with the normalization for satellites being $\sim$ 30 \% smaller than that for central galaxies, which can be attributed to tidal stripping. We further check that our measurements are in excellent agreement with predictions from the IllustrisTNG hydrodynamical simulation. In the second part of this paper, we analyse how the clustering properties of central and satellite galaxies depend on their size. We demonstrate that, independently of the stellar mass threshold adopted, smaller galaxies are more tightly clustered than larger galaxies when either the entire sample or only satellites are considered. The opposite trend is observed on large scales when the size split is performed for the central galaxies alone. Our results place significant constraints for halo-galaxy connection models that link galaxy size with the properties of their hosting haloes.Comment: 15 pages, 12 figures. Accepted for publication in MNRA