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We propose a phenomenological generalization of the models of large-scale structure formation in the Universe by gravitational instability in two ways: we include pressure forces to model multi-streaming, and noise to model fluctuations due…

Astrophysics · Physics 2011-05-23 Thomas Buchert , Alvaro Dominguez , Juan Perez-Mercader

These lecture notes and example problems are based on a course given at the University of Cambridge in Part III of the Mathematical Tripos. Fluid dynamics is involved in a very wide range of astrophysical phenomena, such as the formation…

Solar and Stellar Astrophysics · Physics 2016-05-25 Gordon I. Ogilvie

In gravitationally stratified fluids, length scales are normally much greater in the horizontal direction than in the vertical one. When modelling these fluids it can be advantageous to use the hydrostatic approximation, which filters out…

Instrumentation and Methods for Astrophysics · Physics 2013-07-29 Jonathan Braithwaite , Yuri Cavecchi

Motivated by cosmological applications for interacting matters, an extension of the action functional for relativistic fluids is proposed to incorporate the physics of non-adiabatic processes and chemical reactions. The former are…

General Relativity and Quantum Cosmology · Physics 2025-01-30 Damianos Iosifidis , Erik Jensko , Tomi S. Koivisto

We review various approaches to approximating general relativistic effects in hydrodynamic simulations of stellar core collapse and post-bounce evolution. Different formulations of a modified Newtonian gravitational potential are presented.…

Astrophysics · Physics 2009-11-11 Harald Dimmelmeier , Pablo Cerda-Duran , Andreas Marek , Guillaume Faye

We give a pedagogical review of a covariant and fully non-perturbative approach to study nonlinear perturbations in cosmology. In the first part, devoted to cosmological fluids, we define a nonlinear extension of the uniform-density…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 David Langlois , Filippo Vernizzi

We investigate static spherically symmetric perfect fluid models in Newtonian gravity for barotropic equations of state that are asymptotically polytropic at low and high pressures. This is done by casting the equations into a 3-dimensional…

Astrophysics · Physics 2009-11-07 J. Mark Heinzle , Claes Uggla

We study the dynamics of homogeneous and isotropic Friedmann-Lema\^itre-Robertson-Walker cosmological models with positive spatial curvature within the context of mimetic gravity theory by employing dynamical system techniques. Our analysis…

General Relativity and Quantum Cosmology · Physics 2024-09-18 Alberto Fritis , Daniel Villalobos-Silva , Yerko Vásquez , Carlos H. López-Caraballo , Juan Carlos Helo

We present a series of cosmological N-body simulations which make use of the hydrodynamic approach to the evolution of structures (Dominguez 2000). This approach addresses explicitly the existence of a finite spatial resolution and the…

Astrophysics · Physics 2009-11-11 Alexander Knebe , Alvaro Dominguez , Rosa Dominguez-Tenreiro

Two formulations of superfluidity are reviewed: Landau's phenomenological two-fluid model and a relativistic effective field theory description. We demonstrate how the two-fluid formalism can be recovered from the nonrelativistic limit of…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-17 Aline Favero , Heliudson Bernardo

The objective of this work is to revisit fundamental aspects of relativistic hydrodynamics, aiming at the construction of a first course in relativistic hydrodynamics and its applications to astrophysics at the level of end of undergraduate…

General Relativity and Quantum Cosmology · Physics 2022-10-17 R. F. Santos , A. C. Amaro Faria , L. G. Almeida

A description of the dynamics of a collisionless, self-gravitating fluid is developed and applied to follow the development of Large Scale Structures in the Universe. Such description takes on one of the assumptions of the Adhesion…

Astrophysics · Physics 2009-11-07 N. Menci

In this paper, we derive asymptotic models for the propagation of two and three-dimensional gravity waves at the free surface and the interface between two layers of immiscible fluids of different densities, over an uneven bottom. We assume…

Analysis of PDEs · Mathematics 2021-11-18 Vincent Duchene

We present the generalization of a recently introduced modified gravitational potential for self-gravitating fluids. The use of this potential allows for an accurate approximation of general relativistic effects in an otherwise Newtonian…

Astrophysics · Physics 2009-11-13 Bernhard Mueller , Harald Dimmelmeier , Ewald Mueller

This thesis employs the dynamical systems approach to explore two cosmological models: an anisotropic dark energy scenario in a Bianchi-I background and the Generalized SU(2) Proca (GSU2P) theory in a flat FLRW background. In the first…

General Relativity and Quantum Cosmology · Physics 2025-06-23 Santiago García-Serna

We investigate the possibility to approximate relativistic effects in hydrodynamical simulations of stellar core collapse and post-bounce evolution by using a modified gravitational potential in an otherwise standard Newtonian hydrodynamic…

Astrophysics · Physics 2009-11-10 A. Marek , H. Dimmelmeier , H. -Th. Janka , E. Mueller , R. Buras

Modeling galaxy formation in a cosmological context presents one of the greatest challenges in astrophysics today, due to the vast range of scales and numerous physical processes involved. Here we review the current status of models that…

Astrophysics of Galaxies · Physics 2015-09-23 Rachel S. Somerville , Romeel Davé

A relativistic generalisation of a well-known method for approximating the dynamics of topological defects in condensed matter is constructed, and applied to the evolution of domain walls in a cosmological context. It is shown that there…

High Energy Physics - Phenomenology · Physics 2016-08-24 Mark Hindmarsh

Gravitational waves from neutron-star and black-hole binaries carry valuable information on their physical properties and probe physics inaccessible to the laboratory. Although development of black-hole gravitational-wave templates in the…

General Relativity and Quantum Cosmology · Physics 2014-10-30 Charalampos M. Markakis

Structure formation in the Universe has been well-studied within the Eulerian and Lagrangian perturbation theories, where the latter performs substantially better in comparison with N-body simulations. Standing out is the celebrated…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-04 Niels Fardeau , Thomas Buchert , Fosca Al Roumi , Fereshteh Felegary