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In this study, we investigate the growth of structures within the Deser-Woodard nonlocal theory and extend it to various bouncing cosmology scenarios. Our findings show that the observable structure growth rate, $f\sigma_8$, in a…

General Relativity and Quantum Cosmology · Physics 2023-05-10 D. Jackson , R. Bufalo

We study the formation of structure for a universe that undergoes a recent loitering phase. We compare the nonlinear mass distribution to that in a standard, matter dominated cosmology. The statistical aspects of the clustered matter are…

Astrophysics · Physics 2009-10-22 Hume A. Feldman , August E. Evrard

We reproduce the sub-exponential decoherence of one-dimensional quasicondensates observed in recent experiments. Counter-intuitively, the quasicondensates may decohere even when stongly coupled, if the temperature is large enough or the…

Quantum Gases · Physics 2009-08-21 R. G. Scott , D. A. W. Hutchinson

Spherical models of collisionless but quasi-relaxed stellar systems have long been studied as a natural framework for the description of globular clusters. Here we consider the construction of self-consistent models under the same physical…

Astrophysics · Physics 2009-11-13 G. Bertin , A. L. Varri

Flow behavior of a single-component yield stress fluid is addressed on the hydrodynamic level. A basic ingredient of the model is a coupling between fluctuations of density and velocity gradient via a Herschel-Bulkley-type constitutive…

Soft Condensed Matter · Physics 2018-06-07 Markus Gross , Fathollah Varnik

An approach to cosmological modelling is presented that incorporates the inhomogeneous structure of the Cosmic Web, specifically focusing on the interplay between cosmic voids and density walls. We extend the standard homogeneous and…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-12 John Moffat

Speckle patterns produced by coherent X-ray have a close relationship with the internal structure of materials but quantitative inversion of the relationship to determine structure from speckle patterns is challenging. Here, we investigate…

The seceder model illustrates how the desire to be different than the average can lead to formation of groups in a population. We turn the original, agent based, seceder model into a model of network evolution. We find that the structural…

Disordered Systems and Neural Networks · Physics 2007-05-23 Andreas Gronlund , Petter Holme

Coherent structures are solutions to reaction-diffusion systems that are time-periodic in an appropriate moving frame and spatially asymptotic at $x=\pm\infty$ to spatially periodic travelling waves. This paper is concerned with sources…

Analysis of PDEs · Mathematics 2015-05-27 Margaret Beck , Toan Nguyen , Bjorn Sandstede , Kevin Zumbrun

The formation history of rich clusters is investigated using a hybrid N-body simulation in which high spatial and mass resolution can be achieved self-consistently within a small region of a very large volume. The evolution of three massive…

Astrophysics · Physics 2009-10-30 Tereasa G. Brainerd , David M. Goldberg , Jens Verner Villumsen

Even though the abundance and evolution of clusters have been used to study the cosmological parameters including the properties of dark energy owing to their pure dependence on the geometry of the Universe and the power spectrum, it is…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-23 Seokcheon Lee , Kin-Wang Ng

We study the sensitivity of weak lensing by large scale structures to the evolution of dark energy. We explore a 2-parameters model of dark energy evolution, inspired by tracking quintessence models. To this end, we compute the likelihood…

Astrophysics · Physics 2008-11-26 Karim Benabed , Ludovic Van Waerbeke

The discrepancy in nucleation rate densities between simulated and experimental hard spheres remains staggering and unexplained. Suggestively, more strongly sedimenting colloidal suspensions of hard spheres nucleate much faster than weakly…

Soft Condensed Matter · Physics 2021-12-08 Nicholas Wood , John Russo , Francesco Turci , C. Patrick Royall

I examine differences in non-linear structure formation between cosmological models that share a $z=0$ linear power spectrum in both shape and amplitude, but that differ via their growth history. $N$-body simulations of these models display…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-15 Alexander Mead

We investigate the dynamical state of superclusters in Lambda cold dark matter ($\Lambda$CDM) cosmological models, where the density parameter $\Omega_0=0.2-0.4$ and $\sigma_8$ (the rms fluctuation on the $8h^{-1}$Mpc scale) is $0.7-0.9$.…

Astrophysics · Physics 2009-11-07 Mirt Gramann , Ivan Suhhonenko

We investigate nonlinear dynamics near an unstable constant equilibrium in the classical Keller-Segel model. Given any general perturbation of magnitude $\delta$, we prove that its nonlinear evolution is dominated by the corresponding…

Analysis of PDEs · Mathematics 2007-05-23 Yan Guo , Hyung Ju Hwang

Dissipation in granular media leads to interesting phenomena as there are cluster formation and crystallization in non-equilibrium dynamical states. The freely cooling system is examined concerning the energy decay and the cluster evolution…

Statistical Mechanics · Physics 2009-11-10 S. Miller , S. Luding

We consider the Goode-Wainwright representation of the Szekeres cosmological models and calculate the Taylor expansion of the luminosity distance in order to study the effects of the inhomogeneities on cosmographic parameters. Without…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-31 Mattia Villani

Kinetics of separation between the low and high density phases in a single component Lennard-Jones model has been studied via molecular dynamics simulations, at a very low temperature, in the space dimension $d=2$. For densities close to…

Statistical Mechanics · Physics 2017-04-26 Jiarul Midya , Subir K. Das

In an expanding universe, velocity field and gravitational force field are proportional to each other in the linear regime. Neither of these quantities evolve in time and these can be scaled suitably so that the constant of proportionality…

Astrophysics · Physics 2009-10-28 J. S. Bagla , T. Padmanabhan