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Accurately predicting structural properties of dark matter halos is one of the fundamental goals of modern cosmology. We use the new suite of MultiDark cosmological simulations to study the evolution of dark matter halo density profiles,…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-15 Anatoly Klypin , Gustavo Yepes , Stefan Gottlober , Francisco Prada , Steffen Hess

We use numerical simulations of critically-closed cold dark matter (CDM) models to study the effects of numerical resolution on observable quantities. We study simulations with up to $256^3$ particles using the particle-mesh (PM) method and…

Astrophysics · Physics 2009-10-22 James M. Gelb , Edmund Bertschinger

Cloud detection is a specialized application of image recognition and object detection using remotely sensed data. The task presents a number of challenges, including analyzing images obtained in visible, infrared and multi-spectral…

Signal Processing · Electrical Eng. & Systems 2020-07-28 Philippe Reiter

Continuous wavelet transform (CWT) based time-scale and multi-fractal analyses have been carried out on the anode glow related nonlinear floating potential fluctuations in a hollow cathode glow discharge plasma. CWT has been used to obtain…

Plasma Physics · Physics 2010-03-17 Md. Nurujjaman , Ramesh Narayanan , A. N. Sekar Iyengar

We introduce NeedATool (Needlet Analysis Tool), a software for data analysis based on needlets, a wavelet rendition which is powerful for the analysis of fields defined on a sphere. Needlets have been applied successfully to the treatment…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Davide Pietrobon , Amedeo Balbi , Paolo Cabella , Krzysztof M. Gorski

We introduce a new model of the evolution of the concentration of dark matter halos, c(t). For individual halos, our model approximates c(t) as a power law with a time-dependent index, such that at early times, concentration has a nearly…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-27 Dash Stevanovich , Andrew P. Hearin , Daisuke Nagai

Dark matter density is formally infinite at the location of caustic surfaces, where dark matter sheet folds in phase space. The caustics separate multi-stream regions with different number of streams. Volume elements change the parity by…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Segei F. Shandarin

We train a novel deep learning architecture to perform likelihood-free inference on the value of the cosmological parameters from halo catalogs of the Quijote N-body simulations. Our model takes as input a halo catalog where each halo is…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-23 Atrideb Chatterjee , Francisco Villaescusa-Navarro

Modern N-body cosmological simulations contain billions ($10^9$) of dark matter particles. These simulations require hundreds to thousands of gigabytes of memory, and employ hundreds to tens of thousands of processing cores on many compute…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Stephen Skory , Matthew J. Turk , Michael L. Norman , Alison L. Coil

The rapid evolution of deepfake generation technologies necessitates the development of robust face forgery detection algorithms. Recent studies have demonstrated that wavelet analysis can enhance the generalization abilities of forgery…

Computer Vision and Pattern Recognition · Computer Science 2025-10-22 Siran Peng , Tianshuo Zhang , Li Gao , Xiangyu Zhu , Haoyuan Zhang , Kai Pang , Zhen Lei

Dark matter halos can enter a phase of gravothermal core--collapse in the presence of self-interactions. This phase that follows a core--expansion phase is thought to be subdominant due to the long time-scales involved. However, it has been…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-01 Neev Shah , Susmita Adhikari

Time-frequency methods for vibration-based gearbox faults detection have been considered the most efficient method. Among these methods, continuous wavelet transform (CWT) as one of the best time-frequency method has been used for both…

Machine Learning · Computer Science 2016-06-23 Amir Hosein Zamanian , Abdolreza Ohadi

We give a summary of recent results on spatial and velocity biases in cosmological models. Progress in numerical techniques made it possible to simulate halos in large volumes with a such accuracy that halos survive in dense environments of…

Astrophysics · Physics 2007-05-23 Anatoly Klypin

Large-scale sky surveys require companion large volume simulated mock catalogs. To ensure precision cosmology studies are unbiased, the correlations in these mocks between galaxy properties and their large-scale environments must be…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-25 Sujatha Ramakrishnan , Aseem Paranjape , Ravi K. Sheth

We present two methods for detecting patterns and clusters in high dimensional time-dependent functional data. Our methods are based on wavelet-based similarity measures, since wavelets are well suited for identifying highly discriminant…

Methodology · Statistics 2013-02-15 Anestis Antoniadis , Xavier Brossat , Jairo Cugliari , Jean-Michel Poggi

If the concordance $\Lambda$CDM model is a true description of the universe, it should also properly predict the properties and structure of dark matter haloes, where galaxies are born. Using N-body simulations with a broad scale of mass…

Astrophysics · Physics 2016-08-15 P. Nurmi , P. Heinämäki , E. Saar , M. Einasto , J. Holopainen , V. J. Martínez , J. Einasto

We present the Synthetic UniveRses For Surveys ({\sc surfs}) simulations, a set of N-body/Hydro simulations of the concordance $\Lambda$ Cold Dark Matter (\LCDM) cosmology. These simulations use Planck cosmology, contain up to 10 billion…

We consider wavelets as a tool to perform a variety of tasks in the context of analyzing cosmic microwave background (CMB) maps. Using Spherical Haar Wavelets we define a position and angular-scale-dependent measure of power that can be…

Astrophysics · Physics 2009-10-31 L. Tenorio , A. H. Jaffe , S. Hanany , C. H. Lineweaver

Cosmological neutral hydrogen (HI) surveys provide a promising tomographic probe of the post-reionization era and of the standard model of cosmology. Simulations of this signal are crucial for maximizing the utility of these surveys. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-09 Pascal Hitz , Pascale Berner , Devin Crichton , John Hennig , Alexandre Refregier

Continuous wavelet analysis has been increasingly employed in various fields of science and engineering due to its remarkable ability to maintain optimal resolution in both space and scale. Here, we introduce wavelet-based statistics,…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-29 Yun Wang , Hua-Yu Yang , Ping He