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It is known how to choose initial data for Einstein's equations describing an arbitrary number of black holes at a moment of time symmetry. This idea has been used to give insight into the cosmological averaging problem. We study the local…

General Relativity and Quantum Cosmology · Physics 2018-07-11 Ingemar Bengtsson , Irina Galstyan

We undertake the task of studying the non-linear dynamics of quantum gravity motivated alternatives to black holes that in the classical limit appear as ultra-compact shells of matter. We develop a formalism that should be amenable to…

General Relativity and Quantum Cosmology · Physics 2021-12-15 Ulf Danielsson , Luis Lehner , Frans Pretorius

We construct exact initial data for closed cosmological models filled with regularly arranged black holes in the presence of $\Lambda$. The intrinsic geometry of the 3-dimensional space described by this data is a sum of simple closed-form…

General Relativity and Quantum Cosmology · Physics 2017-03-15 Jessie Durk , Timothy Clifton

We present a flexible and efficient method to construct triaxial dynamical models of galaxies with a central black hole, using Schwarzschild's orbital superposition approach. Our method is general and can deal with realistic luminosity…

The dynamics of black hole seeds in high redshift galaxies is key to understand their ability to grow via accretion and to pair in close binaries during galactic mergers. To properly follow the dynamics of black holes we develop a…

Astrophysics of Galaxies · Physics 2019-05-27 Hugo Pfister , Marta Volonteri , Yohan Dubois , Massimo Dotti , Monica Colpi

We review the methods used to study the orbital structure and chaotic properties of various galactic models and to construct self-consistent equilibrium solutions by Schwarzschild's orbit superposition technique. These methods are…

Astrophysics of Galaxies · Physics 2014-04-09 Eugene Vasiliev

A class of four dimensional spherically symmetric and static geometries with constant topological Euler density is studied. These geometries are shown to solve the coupled Einstein-Maxwell system when non-linear Born-Infeld-like…

General Relativity and Quantum Cosmology · Physics 2016-11-23 Pedro Bargueño , Elias C. Vagenas

We describe an improved, practical method for constructing galaxy models that match an arbitrary set of observational constraints, without prior assumptions about the phase-space distribution function (DF). Our method is an extension of…

Astrophysics · Physics 2009-10-31 Nicolas Cretton , P. Tim de Zeeuw , Roeland P. van der Marel , Hans-Walter Rix

(Abridged:) Schwarzschild's method was used to construct equilibrium solutions to the collisionless Boltzmann equation corresponding to a Plummer sphere, which were compared with analytical results to test the robustness of the numerical…

Astrophysics · Physics 2007-05-23 Christos Siopis

We consider a wide class of static spherically symmetric black holes of arbitrary dimension with a photon sphere (a hypersurface on which a massless particle can orbit the black hole on unstable circular null geodesics). This class includes…

General Relativity and Quantum Cosmology · Physics 2010-05-20 Yves Décanini , Antoine Folacci , Bernard Raffaelli

(ABRIDGED) We present a new Schwarzschild orbit-superposition code designed to model discrete datasets composed of velocities of individual kinematic tracers in a dynamical system. This constitutes an extension of previous implementations…

Astrophysics · Physics 2009-11-13 Julio Chanamé , Jan Kleyna , Roeland van der Marel

Tremendous progress has been made recently in modelling the morphology and kinematics of centers of galaxies. Increasingly realistic models are built for central bar, bulge, nucleus and black hole of galaxies, including our own. The newly…

Astrophysics · Physics 2009-10-31 HongSheng Zhao

We fit axisymmetric 3-integral dynamical models to NGC3379 using the line-of-sight velocity distribution obtained from HST/FOS spectra of the galaxy center and ground-based long-slit spectroscopy along four position angles, with the light…

Dynamical modelling can be used to constrain the masses of central black holes; however, modelling massive galaxies is challenging due to their complexity. In this work, we report six new supermassive black hole mass measurements of massive…

Two distinct non-singular interior models that describe anisotropic spherical configurations are presented in this work. We develop the Einstein field equations and the associated mass function in accordance with a static spherical…

General Relativity and Quantum Cosmology · Physics 2025-10-10 M. Sharif , Tayyab Naseer , Hira Shadab

We demonstrate that the nuclei of galaxies containing supermassive black holes can be triaxial in shape. Schwarzschild's method was first used to construct self-consistent orbital superpositions representing nuclei with axis ratios of…

Astrophysics · Physics 2009-11-07 M. Y. Poon , David Merritt

The scattering of spinning test particles by a Schwarzschild black hole is studied. The motion is described according to the Mathisson-Papapetrou-Dixon model for extended bodies in a given gravitational background field. The equatorial…

General Relativity and Quantum Cosmology · Physics 2018-08-21 Donato Bini , Andrea Geralico

In the static and infalling spherical-shell models of optically thin accretion on Schwarzschild black hole, the formulas for the integrated intensities observed by a distant observer are derived, and by taking the monochromatic emission…

General Relativity and Quantum Cosmology · Physics 2025-06-19 Bofeng Wu , En-Wei Liang , Xiao Zhang

We study regular Schwarzschild black holes in General Relativity as an alternative to the singular counterpart. We analyze two types of solutions which are completely parameterised by the ADM mass alone. We find that both families of…

General Relativity and Quantum Cosmology · Physics 2025-02-20 Roberto Casadio , Alexander Kamenshchik , Jorge Ovalle

The orbital dynamics of a spacecraft orbiting around irregular small celestial bodies is a challenging problem. Difficulties to model the gravity field of these bodies arise from the poor knowledge of the exact shape as observed from the…

Earth and Planetary Astrophysics · Physics 2023-07-26 L. B. T. Santos , L. O. Marchi , P. A. Sousa-Silva , D. M. Sanchez , S. Aljbaae , A. F. B. A. Prado
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