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We use oblate axisymmetric dynamical models including dark halos to determine the orbital structure of intermediate mass to massive Coma early-type galaxies. We find a large variety of orbital compositions. Averaged over all sample galaxies…

By manipulating the spherical Jeans equation, Wolf et al. (2010) show that the mass enclosed within the 3D deprojected half-light radius r_1/2 can be determined with only mild assumptions about the spatial variation of the stellar velocity…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Joe Wolf

In this paper, we consider the anisotropic $\alpha$-Gauss curvature flow for complete noncompact convex hypersurfaces in the Euclidean space with the anisotropy determined by a smooth closed uniformly convex Wulff shape. We show that for…

Differential Geometry · Mathematics 2024-04-17 Shujing Pan , Yong Wei

We present exact kinematic consistency relations for cosmological structures that do not vanish at equal times and can thus be measured in surveys. These rely on cross-correlations between the density and velocity, or momentum, fields.…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-08 Luca Alberto Rizzo , David F. Mota , Patrick Valageas

We construct a dynamical model of the Milky Way disk from a data set, which combines Gaia EDR3 and APOGEE data throughout Galactocentric radii between $5.0\leq R\leq19.5$ kpc. We make use of the spherically-aligned Jeans Anisotropic Method…

Astrophysics of Galaxies · Physics 2021-08-05 Maria Selina Nitschai , Anna-Christina Eilers , Nadine Neumayer , Michele Cappellari , Hans-Walter Rix

We study the consequences of a homogeneous dark energy fluid having a non-vanishing velocity with respect to the matter and radiation large-scale rest frames. We consider homogeneous anisotropic cosmological models with four fluids…

Astrophysics · Physics 2008-11-26 Jose Beltran Jimenez , Antonio L. Maroto

This is a somewhat extended version of the original July 93 report. It is proved that the cosmological density perturbation is associated with a peculiar velocity field. This allows a simple formulation of cosmological perturbation theory,…

Astrophysics · Physics 2010-11-01 Marco Bruni , David H. Lyth

Several works have recently applied Jeans modelling to Gaia-based datasets to infer the circular velocity curve for the Milky Way. Such works have consistently found evidence for a continuous decline in the rotation curve beyond $\sim$15kpc…

Astrophysics of Galaxies · Physics 2024-12-04 Orlin Koop , Teresa Antoja , Amina Helmi , Thomas M. Callingham , Chervin F. P. Laporte

Using cosmological N-body simulations we study the line-of-sight velocity distribution of dark matter haloes focusing on the lowest-order even moments, dispersion and kurtosis, and their application to estimate the mass profiles of…

Astrophysics · Physics 2009-11-13 Radoslaw Wojtak , Ewa L. Lokas , Stefan Gottloeber , Gary A. Mamon

We analyze an alternative theory of gravity characterized by metrics that are tensor density of rank(0,2)and weight-1/2.The metric compatibility condition is supposed to hold. The simplest expression for the action of gravitational field is…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Amir H. Abbassi , Amir M. Abbassi

We present a numerical study of the cosmic density vs. velocity divergence relation (DVDR) in the mildly non-linear regime. We approximate the dark matter as a non-relativistic pressureless fluid, and solve its equations of motion on a grid…

Astrophysics · Physics 2009-10-31 Andrzej Kudlicki , Michal Chodorowski , Tomasz Plewa , Michal Różyczka

We study the implications of a pseudo-phase-space density power-law for the anisotropy profile of a Milky Way-like dark matter halo. Requiring that the anisotropy parameter does not take non-physical values within the virial radius places a…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-18 Daniel R. Hunter

We consider a generic type of dark energy fluid, characterised by a constant equation of state parameter w and sound speed c_s, and investigate the impact of dark energy clustering on cosmic structure formation using the spherical collapse…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Tobias Basse , Ole Eggers Bjaelde , Yvonne Y. Y. Wong

We explore an autonomous system analysis of dark energy models with interactions between dark energy and cold dark matter in a general systematic approach to cosmological fluids. We investigate two types of models such as local and…

General Relativity and Quantum Cosmology · Physics 2024-03-14 Parth Shah , Gauranga C. Samanta , Kazuharu Bamba , R. Myrzakulov

We investigate the simplest quintessence dissipative dark matter attractor cosmology characterized by a constant quintessence baryotropic index and a power--law expansion. We show a class of accelerated coincidence--solving attractor…

Astrophysics · Physics 2009-11-06 Luis P. Chimento , Alejandro S. Jakubi , Norberto A. Zuccala

If the dark energy equation of state is anisotropic, the expansion rate of the universe becomes direction-dependent at late times. We show that such models are not only cosmologically viable but that they could explain some of the observed…

Astrophysics · Physics 2010-11-11 Tomi Koivisto , David F. Mota

In a previous paper we have introduced a new cosmological model that we called the logotropic model. The logotropic model is able to account, without free parameter, for the constant surface density of the dark matter halos, for their…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Pierre-Henri Chavanis

An anisotropic surface energy is the integral of an energy density that depends on the normal at each point over the considered surface, and it is a generalization of surface area. The minimizer of such an energy among all closed surfaces…

Differential Geometry · Mathematics 2019-03-20 Yoshiki Jikumaru , Miyuki Koiso

Several recent studies suggest a correlation between dark matter halo mass and the shape of the density profile. We re-analyze simulations from Ricotti (2003) in which such a correlation was proposed. We use a standard analysis of the halo…

Astrophysics · Physics 2009-11-13 Massimo Ricotti , Andrew Pontzen , Matteo Viel

(Shortened) The combination of lensing and stellar dynamics breaks the mass-anisotropy degeneracy and provides stringent constraints on the mass distribution in early-type (E/S0) galaxies out to z~1. We present the combined results from the…

Astrophysics · Physics 2009-11-10 Tommaso Treu , Leon V. E. Koopmans
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