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Related papers: Genus statistics using the Delaunay tessellation f…

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The density fields constructed by traditional mass assignment methods are susceptible to irritating discreteness, which hinders morphological measurements of cosmic large-scale structure (LSS) through Minkowski functionals (MFs). For…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-22 Yu Liu , Yu Yu , Pengjie Zhang , Hao-Ran Yu

We introduce a method for generating a continuous, mass-conserving and high-order differentiable density field from a discrete point distribution such as particles or halos from an N-body simulation or galaxies from a spectroscopic survey.…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-17 Miguel A. Aragon-Calvo

We investigate the ability of three reconstruction techniques to analyze and investigate weblike features and geometries in a discrete distribution of objects. The three methods are the linear Delaunay Tessellation Field Estimator (DTFE),…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Erwin Platen , Rien van de Weygaert , Bernard J. T. Jones , Gert Vegter , Miguel A. Aragon-Calvo

We measure the three-dimensional topology of large-scale structure in the Sloan Digital Sky Survey (SDSS). This allows the genus statistic to be measured with unprecedented statistical accuracy. The sample size is now sufficiently large to…

The lecture notes describe the Delaunay Tessellation Field Estimator for Cosmic Web analysis. The high sensitivity of Voronoi/Delaunay tessellations to the local point distribution is used to obtain estimates of density and related…

Astrophysics · Physics 2017-03-08 Rien van de Weygaert , Willem Schaap

Here we introduce the Delaunay Density Estimator Method. Its purpose is rendering a fully volume-covering reconstruction of a density field from a set of discrete data points sampling this field. Reconstructing density or intensity fields…

Astrophysics · Physics 2007-05-23 W. E. Schaap , R. van de Weygaert

We apply the Delaunay Tessellation Field Estimator (DTFE) to reconstruct and analyze the matter distribution and cosmic velocity flows in the Local Universe on the basis of the PSCz galaxy survey. The prime objective of this study is the…

Astrophysics · Physics 2007-07-19 Emilio Romano-Diaz , Rien van de Weygaert

We present a novel method for computing the Minkowski Functionals from isodensity surfaces extracted directly from the Delaunay tessellation of a point distribution. This is an important step forward compared to the previous cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-23 Miguel A. Aragon-Calvo , Sergei F. Shandarin , Alexander Szalay

We measure the topology (genus curve) of the galaxy distribution in a mock redshift catalog designed to resemble the upcoming Sloan Digital Sky Survey (SDSS). The catalog, drawn from a large N-body simulation of a Lambda-CDM cos- mological…

The application of Voronoi and Delaunay tessellation based methods for reconstructing continuous fields from discretely sampled data sets is discussed. The succesfull operation as ``multidimensional interpolation'' method is corroborated…

Astrophysics · Physics 2009-10-31 Rien van de Weygaert , Willem Schaap

We present DisPerSE, a novel approach to the coherent multi-scale identification of all types of astrophysical structures, and in particular the filaments, in the large scale distribution of matter in the Universe. This method and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Thierry Sousbie

We describe two new -- stochastic-geometrical -- methods to obtain reliable velocity field statistics from N-body simulations and from any general density and velocity fluctuation field sampled at a discrete set of locations. These methods,…

Astrophysics · Physics 2007-05-23 Rien van de Weygaert , Francis Bernardeau

We use the Delaunay Tessellation Field Estimator (DTFE) to study the one-point density distribution functions of the Millennium (MS) and Millennium-II (MS-II) simulations. The DTFE technique is based directly on the particle positions,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Biswajit Pandey , Simon D. M. White , Volker Springel , Raul Angulo

We present the results of a study confronting density maps reconstructed by the Delaunay Tessellation Field Estimator (DTFE) and by regular SPH kernel-based techniques. The comparison between the two methods clearly demonstrates the…

Astrophysics · Physics 2009-11-07 F. I. Pelupessy , W. E. Schaap , R. van de Weygaert

We have developed a galaxy cluster finding technique based on the Delaunay Tessellation Field Estimator (DTFE) combined with caustic analysis. Our method allows us to recover clusters of galaxies within the mass range of 10^12 to 10^16…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-06 Hector J. Ibarra-Medel , Maritza Lara-Lopez , Omar Lopez-Cruz

We study the evolution of non-linear structure as a function of scale in samples from the 2dF Galaxy Redshift Survey, constituting over 221 000 galaxies at a median redshift of z=0.11. The two flux-limited galaxy samples, located near the…

Astrophysics · Physics 2009-03-13 J. Berian James , Matthew Colless , Geraint F. Lewis , John A. Peacock

We review the analysis of the Cosmic Web by means of an extensive toolset based on the use of Delaunay and Voronoi tessellations. The Cosmic Web is the salient and pervasive foamlike pattern in which matter has organized itself on scales of…

Instrumentation and Methods for Astrophysics · Physics 2009-12-18 Rien van de Weygaert , Miguel A. Aragon-Calvo , Bernard J. T. Jones , Erwin Platen

The major uncertainties in studies of the multi-scale structure of the Universe arise not from observational errors but from the variety of legitimate definitions and detection methods for individual structures. To facilitate the study of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 M. J. Way , P. R. Gazis , Jeffrey D. Scargle

Robust measurements of cosmological parameters from galaxy surveys rely on our understanding of systematic effects that impact the observed galaxy density field. In this paper we present, validate, and implement the idea of adopting the…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-20 Mehdi Rezaie , Hee-Jong Seo , Ashley J. Ross , Razvan C. Bunescu

We introduce two new methods to obtain reliable velocity field statistics from N-body simulations, or indeed from any general density and velocity fluctuation field sampled by discrete points. These methods, the {\it Voronoi tessellation…

Astrophysics · Physics 2017-03-08 Francis Bernardeau , Rien van de Weygaert
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