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Related papers: The Cosmological Mass Function with 1D Gravity

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We present a new method to study the characteristic scales of collapse and fragmentation in galactic disks. Clump formation is seeded in simulations via controlled perturbations with a specified wavelength and velocity. These are applied to…

Astrophysics of Galaxies · Physics 2019-05-08 S. M. Benincasa , J. W. Wadsley , H. M. P. Couchman , A. R. Pettit , E. J. Tasker

Two categories of results regarding quantum measurements are derived in this work and applied to the problem of collapse. The first category is concerned with local and transient features of the entanglement between a macroscopic measuring…

Quantum Physics · Physics 2016-03-01 Roland Omnès

We use the semi-analytical approach to analyze gravitational lensing of quasars by dark halos in various cold dark matter (CDM) cosmologies, in order to determine the sensitivity of the prediction probabilities of images separations to the…

Astrophysics · Physics 2009-10-31 Li-Xin Li , Jeremiah P. Ostriker

Context. Deur (2014) and Winters et al. (2023) proposed an empirical relation between the dark to total mass ratio and ellipticity in elliptical galaxies from their observed total dynamical mass-to-light ratio data M/L = (14.1 +/-…

Astrophysics of Galaxies · Physics 2024-02-07 Pierfrancesco Di Cintio

A Bayesian statistical formalism is developed to quantify the level at which the mass function slope (alpha) and the projected cumulative mass fraction (f) of (CDM) substructure in strong gravitational-lens galaxies, with arcs or Einstein…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 S. Vegetti , L. V. E. Koopmans

This paper looks into the problem of grasping unknown objects in a cluttered environment using 3D point cloud data obtained from a range or an RGBD sensor. The objective is to identify graspable regions and detect suitable grasp poses from…

Robotics · Computer Science 2018-07-30 Olyvia Kundu , Swagat Kumar

We study topologically massive (2+1)-dimensional gravity with a negative cosmological constant. The masses of the linearized curvature excitations about AdS_3 backgrounds are not only shifted from their flat background values but, more…

High Energy Physics - Theory · Physics 2010-04-28 S. Carlip , S. Deser , A. Waldron , D. K. Wise

Doppler lensing is the apparent change in object size and magnitude due to peculiar velocities. Objects falling into an overdensity appear larger on its near side, and smaller on its far side, than typical objects at the same redshifts.…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-03 David J. Bacon , Sambatra Andrianomena , Chris Clarkson , Krzysztof Bolejko , Roy Maartens

In ``Decoherence of macroscopic closed systems within Newtonian quantum gravity'' (Kay B S 1998 Class. Quantum Grav. 15 L89-L98) it was argued that, given a many-body Schroedinger wave function \psi(x_1,...,x_N) for the centre-of-mass…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Varqa Abyaneh , Bernard S. Kay

We investigate matter density perturbations in models of structure formation with or without causal/acausal source. Under the fluid approximation in the linear theory, we first derive full perturbation equations in flat space with a…

Astrophysics · Physics 2007-05-23 Jiun-Huei Proty Wu

A tetrad-based procedure is presented for solving Einstein's field equations for spherically-symmetric systems; this approach was first discussed by Lasenby et al. in the language of geometric algebra. The method is used to derive metrics…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Roshina Nandra , Anthony N. Lasenby , Michael P. Hobson

In this paper, extending past works of Del Popolo, we show how a high precision mass function (MF) can be obtained using the excursion set approach and an improved barrier taking implicitly into account a non-zero cosmological constant, the…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-29 Antonino Del Popolo , Francesco Pace , Morgan Le Delliou

In cosmology, a basic explanation of the observed concentration of mass in singular structures is provided by the Zeldovich approximation, which takes the form of free-streaming flow for perturbations of a uniform Einstein-de Sitter…

Analysis of PDEs · Mathematics 2025-12-18 Jian-Guo Liu , Robert L. Pego

The standard cold dark matter (CDM) model predicts too many and too dense small structures. We consider an alternative model that the dark matter undergoes two-body decays with cosmological lifetime $\tau$ into only one type of massive…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 Dalong Cheng , M. -C. Chu , Jiayu Tang

The nature of structure formation around the particle free streaming scale is still far from understood. Many attempts to simulate hot, warm, and cold dark matter cosmologies with a free streaming cutoff have been performed with…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Aurel Schneider , Robert E. Smith , Darren Reed

We estimate the Mass Function of void galaxies in the second public data release of the Sloan Digital Sky Survey from a sample of 1000 galaxies with local density contrasts of delta_v < -0.6. The galaxy sample is split into ellipticals and…

We examine higher-curvature gravities whose FLRW configurations are specified by equations of motion which are of second order in derivatives, just like in Einstein gravity. We name these theories Cosmological Gravities and initiate a…

General Relativity and Quantum Cosmology · Physics 2026-04-22 Javier Moreno , Ángel J. Murcia

Constraints on cosmological models from strong gravitational lensing statistics are investigated. We pay particular attention to the role of the velocity function in the calculation of the lensing probability. The velocity function derived…

Astrophysics · Physics 2009-10-28 Takahiro T. Nakamura , Yasushi Suto

We present a simple and intuitive approximation for solving perturbation theory (PT) of small cosmic fluctuations. We consider only the spherically symmetric or monopole contribution to the PT integrals, which yields the exact result for…

Astrophysics · Physics 2009-10-30 P. Fosalba , E. Gaztanaga

In the ellipsoidal collapse model, the critical density for the collapse of a gravitationally bound object is a function of its mass. In the excursion set formalism, this translates into a moving barrier problem such that the mass function…

Astrophysics · Physics 2007-05-23 Asim Mahmood , R. Rajesh