Browsing by Author "Yadav, J"

Now showing 1 - 4 of 4
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    Bezier-Baskakov-Beta Type Operators
    (2022-12) Kajla, V; Ozger, F; Yadav, J
    In this study, we construct the Bezier- Baskakov-Beta type operators. We provide elements of Lipschitz type space, a direct approximation theorm by means of modulus of continuity ωρℓ(ζ,t)(0 ≤ ℓ ≤ 1) and approximation rate for functions having derivatives of bounded variation. We support the theoretical parts by computer graphics.
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    Bivariate Lupas¸-Durrmeyer type operators involving P ´olya distribution
    (2023-03) Yadav, J; Mohiuddine, A; Kajla, A
    In this paper, we consider a bivariate extension of blending type approximation by Lupas¸- Durrmeyer type operators involving Polya Distribution. We illustrate the convergence rate of these type ´ operators using Peetre’s K-functional, modulus of smoothness and for functions in a Lipschitz type space.
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    Interactions of galaxies outside clusters and massive groups
    (2018-04) Yadav, J; Chen, X
    We investigate the dependence of physical properties of galaxies on small- and large-scale density environment. The galaxy population consists of mainly passively evolving galaxies in comparatively low density regions of Sloan Digital Sky Survey (SDSS). We adopt (i) local density, ρ20, derived using adaptive smoothing kernel, (ii) projected distance, r p, to the nearest neighbor galaxy and (iii) the morphology of the nearest neighbor galaxy as various definitions of environment parameters of every galaxy in our sample. In order to detect long-range interaction effects, we group galaxy interactions into four cases depending on morphology of the target and neighbor galaxies. This study builds upon an earlier study by Park and Choi (2009) by including improved definitions of target and neighbor galaxies, thus enabling us to better understand the effect of “the nearest neighbor” interaction on the galaxy. We report that the impact of interaction on galaxy properties is detectable at least up to the pair separation corresponding to the virial radius of (the neighbor) galaxies. This turns out to be mostly between 210 and 360 h−1kpc for galaxies included in our study. We report that early type fraction for isolated galaxies with r p > rvir,nei is almost ignorant of the background density and has a very weak density dependence for closed pairs. Star formation activity of a galaxy is found to be crucially dependent on neighbor galaxy morphology. We find star formation activity parameters and structure parameters of galaxies to be independent of the large-scale background density. We also exhibit that changing the absolute magnitude of the neighbor galaxies does not affect significantly the star formation activity of those target galaxies whose morphology and luminosities are fixed.
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    Investigating Cosmic Homogeneity Using Multi-fractal Analysis of the SDSS-IV eBOSS DR16 Quasar Catalog
    (2024-04) Goyal, P; Malik, S; Yadav, J; Seshadri, T
    We analyze the volume-limited subsamples extracted from the sixteenth data release of the SDSS-IV eBOSS quasar survey spanning a redshift interval of 0.8 < 𝑧 < 2.2, to estimate the scale of transition to homogeneity in the Universe. The multi-fractal analysis used for this purpose considers the scaling behavior of different moments of quasar distribution in different density environments. This analysis gives the spectrum of generalized dimension 𝐷𝑞, where positive values of 𝑞 characterize the scaling behavior in over-dense regions and the negative ones in under-dense regions. We expect fractal correlation dimension 𝐷𝑞 (𝑟) = 3, for a homogeneous, random point distribution in 3-Dimensions. The fractal correlation dimension 𝐷𝑞 (𝑟), corresponding to 𝑞 = 2 obtained in our study stabilizes in the range (2.8-2.9) for scales 𝑟 > 80 ℎ −1 Mpc. The observed quasar distribution shows consistency with the simulated mock data and the random distribution of quasars within one sigma. Further, the generalized dimension spectrum 𝐷𝑞 (𝑟) also reveals transition to homogeneity beyond > 110 ℎ −1 Mpc, and the dominance of clustering at small scales𝑟 < 80 ℎ −1 Mpc. Consequently, our study provides strong evidence for the homogeneity in SDSS quasar distribution, offering insights into large-scale structure properties and, thus can play a pivotal role in scrutinizing the clustering properties of quasars and its evolution in various upcoming surveys such as Dark Energy Spectroscopic Instrument (DESI) and Extremely Large Telescope (ELT).