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相关论文: Hierarchical Clustering in ${\Lambda}$CDM Cosmolog…

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The large-scale structure of the universe is comprised of virialized blob-like clusters, linear filaments, sheet-like walls and huge near empty three-dimensional voids. Characterizing the large scale universe is essential to our…

宇宙学与河外天体物理 · 物理学 2024-06-06 Nithin Shivshankar , Pratyush Pranav , Vijay Natarajan , Rien van de Weygaert , E G Patrick Bos , Steven Rieder

Building upon [2308.02636], we investigate the constraining power of persistent homology on cosmological parameters and primordial non-Gaussianity in a likelihood-free inference pipeline utilizing machine learning. We evaluate the ability…

宇宙学与河外天体物理 · 物理学 2025-09-22 Juan Calles , Jacky H. T. Yip , Gabriella Contardo , Jorge Noreña , Adam Rouhiainen , Gary Shiu

We investigate the properties of the FLRW flat cosmological models in which the vacuum energy density evolves with time, $\Lambda(t)$. Using different versions of the $\Lambda(t)$ model, namely quantum field vacuum, power series vacuum and…

宇宙学与河外天体物理 · 物理学 2015-05-13 S. Basilakos , M. Plionis , J. Sola

Inspired by the well-studied $\Lambda_{\rm s}$CDM model, we propose and investigate a class of dynamical dark energy models that evolve from a negative cosmological constant, transitioning to a positive value at low redshifts. Specifically,…

广义相对论与量子宇宙学 · 物理学 2025-09-09 Mariam Bouhmadi-López , Beñat Ibarra-Uriondo

Galaxy clusters in the Universe occupy the important position of nodes of the cosmic web. They are connected among them by filaments, elongated structures composed of dark matter, galaxies, and gas. The connection of galaxy clusters to…

宇宙学与河外天体物理 · 物理学 2023-07-05 Nicola Malavasi , Jenny G. Sorce , Klaus Dolag , Nabila Aghanim

The mass function of cluster-size halos and their redshift distribution are computed for 12 distinct accelerating cosmological scenarios and confronted to the predictions of the conventional flat $\Lambda$CDM model. The comparison with…

宇宙学与河外天体物理 · 物理学 2010-10-27 S. Basilakos , M. Plionis , J. A. S. Lima

Using cosmic voids to probe the growth rate of cosmic structure, and hence the nature of dark energy, is particularly interesting in the context of modified gravity theories that rely on the screening mechanism. In this work we improve the…

宇宙学与河外天体物理 · 物理学 2017-10-11 Ixandra Achitouv

We report the {\em first} systematic study of the supercluster-void network in the $\Lambda$CDM concordance cosmology treating voids and superclusters on an equal footing. We study the dark matter density field in real space smoothed with…

天体物理学 · 物理学 2009-11-10 Sergei F. Shandarin

We study the evolution of galaxy clustering in various cosmological models with quintessence. We investigate how the analytical predictions vary with change of dark energy equation of state $w_X$. Comparing these predictions against…

天体物理学 · 物理学 2015-06-24 Dipak Munshi , Cristiano Porciani , Yun Wang

A large set of TREESPH simulations is used to test the global morphology of galaxy clusters and its evolution against X-ray data. A powerful method to investigate substructures in galaxy clusters are the power ratios introduced by Buote &…

天体物理学 · 物理学 2007-05-23 R. Valdarnini , S. Ghizzardi , S. Bonometto

In the context of a spatially flat $\Lambda(t)$CDM cosmology, we investigate interacting dark energy (IDE) scenarios characterized by phenomenological interaction terms proportional to the Hubble expansion rate and the dark energy density.…

宇宙学与河外天体物理 · 物理学 2026-02-13 A. A. Escobal , H. A. P. Macedo , J. F. Jesus , R. C. Nunes , J. A. S. Lima

In a previous paper, we proposed a heterotic dark energy model, called $\Lambda$HDE, in which dark energy is composed of two components: cosmological constant (CC) and holographic dark energy (HDE). The aim of this work is to give a more…

宇宙学与河外天体物理 · 物理学 2017-02-17 Shuang Wang , Sixiang Wen , Lanjun Zhou , Miao Li

We study the dynamical properties of a large body of varying vacuum cosmologies for which dark matter interacts with vacuum. In particular, performing the critical point analysis we investigate the existence and the stability of…

广义相对论与量子宇宙学 · 物理学 2020-02-19 G. Papagiannopoulos , Pavlina Tsiapi , Spyros Basilakos , Andronikos Paliathanasis

Imagine a scenario in which the dark energy forms via the condensation of dark matter at some low redshift. The Compton wavelength therefore changes from small to very large at the transition, unlike quintessence or metamorphosis. We study…

天体物理学 · 物理学 2009-11-07 Bruce A. Bassett , Martin Kunz , David Parkinson , Carlo Ungarelli

We introduce a new technique for following the formation and evolution of galaxies in cosmological N-body simulations. Dissipationless simulations are used to track the formation and merging of dark matter halos as a function of redshift.…

天体物理学 · 物理学 2009-10-30 Guinevere Kauffmann , Joerg M. Colberg , Antonaldo Diaferio , Simon D. M. White

This paper introduces a topological framework for interpreting the internal representations of Multilayer Perceptrons (MLPs). We construct a simplicial tower, a sequence of simplicial complexes connected by simplicial maps, that captures…

机器学习 · 计算机科学 2025-06-03 Eduardo Paluzo-Hidalgo

We investigate the formation, growth, merger history, movement, and destruction of cosmic voids detected via the watershed transform code VIDE in a cosmological N-body dark matter {\Lambda}CDM simulation. By adapting a method used to…

宇宙学与河外天体物理 · 物理学 2015-06-19 P. M. Sutter , Pascal Elahi , Bridget Falck , Julian Onions , Nico Hamaus , Alexander Knebe , Chaichalit Srisawat , Aurel Schneider

We discuss an analytic approach for modeling structure formation in sheets, filaments and knots. This is accomplished by combining models of triaxial collapse with the excursion set approach: sheets are defined as objects which have…

天体物理学 · 物理学 2009-07-07 Jiajian Shen , Tom Abel , H. J. Mo , Ravi Sheth

Persistent homology provides a robust methodology to infer topological structures from point cloud data. Here we explore the persistent homology of point clouds embedded into a probabilistic setting, exploiting the theory of point…

概率论 · 数学 2023-08-07 Daniel Spitz , Anna Wienhard

Convection is a well-studied topic in fluid dynamics, yet it is less understood in the context of networks flows. Here, we incorporate techniques from topological data analysis (namely, persistent homology) to automate the detection and…

动力系统 · 数学 2022-03-15 Minh Quang Le , Dane Taylor