English
Related papers

Related papers: Resolving Subhaloes' Lives with the Hierarchical B…

200 papers

We have studied the merger rate of primordial black holes (PBHs) in the ellipsoidal-collapse model of halo to explain the dark matter abundance by the PBH merger estimated from the gravitational waves detections via the Advanced LIGO…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-11 Saeed Fakhry , Javad T. Firouzjaee , Mehrdad Farhoudi

As an approximate nearest neighbor search technique, hashing has been widely applied in large-scale image retrieval due to its excellent efficiency. Most supervised deep hashing methods have similar loss designs with embedding learning,…

Computer Vision and Pattern Recognition · Computer Science 2019-10-22 Shen Chen , Liujuan Cao , Mingbao Lin , Yan Wang , Xiaoshuai Sun , Chenglin Wu , Jingfei Qiu , Rongrong Ji

A physical understanding of galaxy formation and evolution benefits from an understanding of the connections between galaxies, their host dark matter halos, and their environments. In particular, interactions with more-massive neighbors can…

Astrophysics of Galaxies · Physics 2025-10-01 Haley Bowden , Peter Behroozi

The inner region of a subhalo's density distribution is particularly sensitive to dark matter microphysics, with alternative dark matter models leading to both cored and steeply-rising inner density profiles. This work investigates how the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-25 Kassidy E. Kollmann , James W. Nightingale , Mariangela Lisanti , Andrew Robertson , Oren Slone

In the standard model of cosmic structure formation, dark matter haloes form by gravitational instability. The process is hierarchical: smaller systems collapse earlier, and later merge to form larger haloes. The galaxy clusters, hosted by…

Astrophysics · Physics 2009-11-13 Carlo Giocoli , Lidia Pieri , Giuseppe Tormen

We present a novel hierarchical triplet loss (HTL) capable of automatically collecting informative training samples (triplets) via a defined hierarchical tree that encodes global context information. This allows us to cope with the main…

Computer Vision and Pattern Recognition · Computer Science 2018-10-17 Weifeng Ge , Weilin Huang , Dengke Dong , Matthew R. Scott

Modern galaxy surveys demand extensive survey volumes and resolutions surpassing current dark matter-only simulations' capabilities. To address this, many methods employ effective bias models on the dark matter field to approximate object…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-08 Daniel Forero-Sánchez , Francisco-Shu Kitaura , Francesco Sinigaglia , Jose María Coloma-Nadal , Jean-Paul Kneib

The Blooming Tree (BT) algorithm, based on the hierarchical clustering method, is designed to identify clusters, groups, and substructures from galaxy redshift surveys. We apply the BT algorithm to a wide-field ($10\times 10$ deg$^2$)…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-01 Heng Yu , Antonaldo Diaferio

We use numerical simulations to examine the substructure within galactic and cluster mass halos that form within a hierarchical universe. Clusters are easily reproduced with a steep mass spectrum of thousands of substructure clumps that…

The mass distribution of dark matter haloes is the result of the hierarchical growth of initial density perturbations through mass accretion and mergers. We use an interpretable machine-learning framework to provide physical insights into…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-06 Luisa Lucie-Smith , Susmita Adhikari , Risa H. Wechsler

We describe a new method (\textsc{CompaSO}) for identifying groups of particles in cosmological $N$-body simulations. \textsc{CompaSO} builds upon existing spherical overdensity (SO) algorithms by taking into consideration the tidal radius…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-25 Boryana Hadzhiyska , Daniel Eisenstein , Sownak Bose , Lehman H. Garrison , Nina Maksimova

Studying the formation and evolution of black hole binaries (BHBs) is essential for the interpretation of current and forthcoming gravitational wave (GW) detections. We investigate the statistics of BHBs that form from isolated binaries, by…

High Energy Astrophysical Phenomena · Physics 2019-04-12 Mario Spera , Michela Mapelli , Nicola Giacobbo , Alessandro Alberto Trani , Alessandro Bressan , Guglielmo Costa

We present a comprehensive analysis of the evolution of dark matter subhaloes in the cosmological Bolshoi simulation. We identify a complete set of 12 unique evolution channels by which subhaloes evolve in between simulation outputs, and…

Astrophysics of Galaxies · Physics 2017-04-12 Frank C. van den Bosch

This work addresses and solves the problem of generically tracking black hole event horizons in computational simulation of black hole interactions. Solutions of the hyperbolic eikonal equation, solved on a curved spacetime manifold…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Scott A. Caveny , Matthew Anderson , Richard A. Matzner

The box-covering method plays a fundamental role in the fractal property recognition and renormalization analysis of complex networks. This study proposes the hub-collision avoidance and leaf-node options (HALO) algorithm. In the box…

Physics and Society · Physics 2024-01-05 Feiyan Guo , Jiajun Zhou , Zhongyuan Ruan , Jian Zhang , Lin Qi

Hierarchical Topic Models (HTMs) are useful for discovering topic hierarchies in a collection of documents. However, traditional HTMs often produce hierarchies where lowerlevel topics are unrelated and not specific enough to their…

Information Retrieval · Computer Science 2023-05-17 Simra Shahid , Tanay Anand , Nikitha Srikanth , Sumit Bhatia , Balaji Krishnamurthy , Nikaash Puri

We use simulations of merging galaxies to explore the sensitivity of the morphology of tidal tails to variations of the halo mass distributions in the parent galaxies. Our goal is to constrain the mass of dark halos in well-known merging…

Astrophysics · Physics 2008-11-26 John Dubinski , J. Christopher Mihos , Lars Hernquist

We use cosmological LCDM numerical simulations to model the evolution of the substructure population in sixteen dark matter haloes with resolutions of up to seven million particles within the virial radius. The combined substructure…

Astrophysics · Physics 2008-11-26 Darren Reed , Fabio Governato , Thomas Quinn , Jeffrey Gardner , Joachim Stadel , George Lake

Modern machine learning algorithms crucially rely on several design decisions to achieve strong performance, making the problem of Hyperparameter Optimization (HPO) more important than ever. Here, we combine the advantages of the popular…

Machine Learning · Computer Science 2021-10-22 Noor Awad , Neeratyoy Mallik , Frank Hutter

In the cold dark matter model of structure formation, galaxies are assembled hierarchically from mergers and the accretion of subclumps. This process is expected to leave residual substructure in the Galactic dark halo, including partially…

Astrophysics · Physics 2009-11-06 D. Stiff , L. M. Widrow , J. Frieman