Structural properties of artificial halos in non-standard dark matter simulations

Artificial fragmentation of the matter density field causes the formation of spurious groups of particles in N-body simulations of non-standard Dark Matter (DM) models which are characterized by a small scale cut-off in the linear matter power spectrum. These spurious halos alter the prediction of the mass function in a range of masses where differences among DM models are most relevant to observational tests. Using a suite of high resolution simulations we show that the contamination of artificial groups of particles significantly affect the statistics of halo spin, shape and virial state parameters. We find that spurious halos have systematically larger spin values, are highly elliptical or prolate and significantly deviate from virial equilibrium. These characteristics allow us to detect the presence of spurious halos even in non-standard DM models for which the low-mass end of the mass function remains well behaved. We show that selecting halos near the virial equilibrium provides a simple and effective method to remove the bulk of spurious halos from numerical halo catalogs and consistently recover the halo mass function at low masses.Comment: 9 pages, 9 figures, 1 table, added analysis from higher resolution simulation

The Cosmic Mach Number: Comparison from Observations, Numerical Simulations and Nonlinear Predictions

We calculate the cosmic Mach number M - the ratio of the bulk flow of the velocity field on scale R to the velocity dispersion within regions of scale R. M is effectively a measure of the ratio of large-scale to small-scale power and can be a useful tool to constrain the cosmological parameter space. Using a compilation of existing peculiar velocity surveys, we calculate M and compare it to that estimated from mock catalogues extracted from the LasDamas (a LCDM cosmology) numerical simulations. We find agreement with expectations for the LasDamas cosmology at ~ 1.5 sigma CL. We also show that our Mach estimates for the mocks are not biased by selection function effects. To achieve this, we extract dense and nearly-isotropic distributions using Gaussian selection functions with the same width as the characteristic depth of the real surveys, and show that the Mach numbers estimated from the mocks are very similar to the values based on Gaussian profiles of the corresponding widths. We discuss the importance of the survey window functions in estimating their effective depths. We investigate the nonlinear matter power spectrum interpolator PkANN as an alternative to numerical simulations, in the study of Mach number.Comment: 12 pages, 9 figures, 3 table

Family Planning Market in India

This literature review captures existing knowledge across a range of products and players in India's family planning market. The product scope covers condoms, oral contraceptive pills, injectable contraceptives, intra-uterine devices, and male and female sterilization.The broad reach of this analysis brings diverse perspectives together to provide a complete picture of the current state of the market. The review can be particularly useful for field practitioners, donors, and other players looking to understand the current state of discovery in the India family planning market

PkANN: Non-Linear Matter Power Spectrum Interpolation through Artificial Neural Networks

We investigate the interpolation of power spectra of matter fluctuations using artificial neural networks (ANNs). We present a new approach to confront small-scale non-linearities in the matter power spectrum. This ever-present and pernicious uncertainty is often the Achilles&rsquo heel in cosmological studies and must be reduced if we are to see the advent of precision cosmology in the late-time Universe. We detail how an accurate interpolation of the matter power spectrum is achievable with only a sparsely sampled grid of cosmological parameters. We show that an optimally trained ANN, when presented with a set of cosmological parameters (&Omegam h2, &Omegab h2, ns, w0, &sigma8, ∑m&nu and z), can provide a worst-case error &le 1 per cent (for redshift z &le 2) fit to the non-linear matter power spectrum deduced through large-scale N-body simulations, for modes up to k &le 0.9 h Mpc-1. Our power spectrum interpolator, which we label &lsquo PkANN &rsquo, is designed to simulate a range of cosmological models including massive neutrinos and dark energy equation of state w0 ≠ -1. PkANN is accurate in the quasi-non-linear regime (0.1 h Mpc-1 &le k &le 0.9 h Mpc-1) over the entire parameter space and marks a significant improvement over some of the current power spectrum calculators. The response of the power spectrum to variations in the cosmological parameters is explored using PkANN. Using a compilation of existing peculiar velocity surveys, we investigate the cosmic Mach number statistic and show that PkANN not only successfully accounts for the non-linear motions on small scales, but also, unlike N-body simulations which are computationally expensive and/or infeasible, it can be an extremely quick and reliable tool in interpreting cosmological observations and testing theories of structure-formation

PkANN - II. A non-linear matter power spectrum interpolator developed using artificial neural networks

In this paper we introduce PkANN, a freely available software package for interpolating the non-linear matter power spectrum, constructed using Artificial Neural Networks (ANNs). Previously, using Halofit to calculate matter power spectrum, we demonstrated that ANNs can make extremely quick and accurate predictions of the power spectrum. Now, using a suite of 6380 N-body simulations spanning 580 cosmologies, we train ANNs to predict the power spectrum over the cosmological parameter space spanning $3\sigma$ confidence level (CL) around the concordance cosmology. When presented with a set of cosmological parameters ($\Omega_{\rm m} h^2, \Omega_{\rm b} h^2, n_s, w, \sigma_8, \sum m_\nu$ and redshift $z$), the trained ANN interpolates the power spectrum for $z\leq2$ at sub-per cent accuracy for modes up to $k\leq0.9\,h\textrm{Mpc}^{-1}$. PkANN is faster than computationally expensive N-body simulations, yet provides a worst-case error $<1$ per cent fit to the non-linear matter power spectrum deduced through N-body simulations. The overall precision of PkANN is set by the accuracy of our N-body simulations, at 5 per cent level for cosmological models with $\sum m_\nu<0.5$ eV for all redshifts $z\leq2$. For models with $\sum m_\nu>0.5$ eV, predictions are expected to be at 5 (10) per cent level for redshifts $z>1$ ($z\leq1$). The PkANN interpolator may be freely downloaded from http://zuserver2.star.ucl.ac.uk/~fba/PkANNComment: 21 pages, 14 figures, 2 table

Dependence of the dynamical properties of light-cone simulation dark matter halos on their environment

Aims: We study the dependence of the dynamical properties of dark matter halos on their environment in a whole-sky $\Lambda$CDM light-cone simulation extending to $z\sim 0.65$. The properties of interest are halo shape (parametrized by its principal axes), spin and virialisation status, the alignment of halo spin and shape, as well as the shape-shape and spin-spin alignments among halo neighbours. Methods: We define the halo environment using the notion of halo isolation status determined by the distance to its nearest neighbor. This defines a maximum spherical region around each halo devoid of other halos, above the catalog threshold mass. We consider as 'close halo pairs', the pairs that are separated by a distance lower than a specific threshold. In order to decontaminate our results from the known dependence of halo dynamical properties on mass, we use a random sampling procedure in order to compare properties of similar halo abundance distributions. Results: (a) We find a strong dependence of halo properties on their environment, confirming that isolated halos are more aspherical and more prolate with lower spin values. (b) Correlations between halo properties exist and are mostly independent of halo environment. (c) Halo spins are aligned with the minor axis, regardless of halo shape. (d) Close halo neighbors have their major axes statistically aligned, while they show a slight but statistically significant preference for anti-parallel spin directions. The latter result is enhanced for the case of close halo pairs in low-density environments. Furthermore, we find a preference of the spin vectors to be oriented perpendicular to the line connecting such close halo pairs.Comment: 14 pages, 13 figures, submitted to A&

PARAMETRIC ANALYSIS OF A GRINDING PROCESS USING THE ROUGH SETS THEORY

With continuous automation of the manufacturing industries and the development of advanced data acquisition systems, a huge volume of manufacturing-related data is now available which can be effectively mined to extract valuable knowledge and unfold the hidden patterns. In this paper, a data mining tool, in the form of the rough sets theory, is applied to a grinding process to investigate the effects of its various input parameters on the responses. Rotational speed of the grinding wheel, depth of cut and type of the cutting fluid are grinding parameters, and average surface roughness, amplitude of vibration and grinding ratio are the responses. The best parametric settings of the grinding parameters are also derived to control the quality characteristics of the ground components. The developed decision rules are quite easy to understand and can truly predict the response values at varying combinations of the considered grinding parameters

Comparative study of oral iron and intravenous iron sucrose for the treatment of iron deficiency anemia in pregnancy

Background: The aim of this study was to compare the efficacy and safety of iron sucrose with oral iron in the treatment of iron deficiency anemia of pregnancy.Methods: An interventional comparative study was conducted at Jhalawar Medical College, Jhalawar involving 80 pregnant women with iron deficiency anemia from March 2016 to August 2016. Inclusion criteria were gestational age between 24-32 weeks with established iron deficiency anemia, with hemoglobin between 7-10g/dl. Target Hemoglobin was 11 g/dl. In intravenous iron sucrose group iron sucrose dose was calculated from following formula: total iron dose required (mg) = 2.4 x body weight in Kg x (target Hb – Patient’s Hb g/dl) + 500. In oral iron, group patient received ferrous-sulphate 335 mg daily BD. Hb level were reviewed at 2, 4, 6 weeks.Results: Change in Hemoglobin level from baseline significantly higher in IV iron group than oral iron group. In IV iron, group mean value of baseline Hb was 8.07±0.610 g/dl and in oral iron group was 8.48±0.741 g/dl. At the end of 6-week mean hemoglobin in IV iron sucrose was 10.66±0.743 g/dl and in oral iron group was 10.08±0.860 g/dl.Conclusions: Intravenous iron sucrose elevates more Hb than oral iron, with less adverse effects