Article
Astronomy & Astrophysics
Guillermo Perna, Esteban Calzetta
Summary: The dispersion relations for scalar, vector, and tensor modes of a viscous relativistic fluid were calculated and compared with results derived from kinetic theory and causal first-order theories. The study found that different methods show similar dynamics for scalar and vector modes, while the specific divergence-type theory presented contains propagating damped tensor waves. These conclusions support the application of hydrodynamics in problems involving the interaction between fluids and gravitational waves.
Article
Astronomy & Astrophysics
Michail Chabanov, Luciano Rezzolla, Dirk H. Rischke
Summary: The text discusses the suitability of numerical integration in special-relativistic and general-relativistic scenarios, presenting a fully general, causal formulation of relativistic second-order dissipative hydrodynamics. The formulation is tested in specific scenarios and the results can be used as a testbed for numerical codes simulating non-perfect fluids on curved backgrounds.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Jamie F. Townsend, Shu-ichiro Inutsuka, Laszlo Konozsy, Karl W. Jenkins
Summary: This work assesses the dissipative properties of high-order numerical methods for relativistic hydrodynamics and investigates the numerical dissipation of high-order shock-wave capturing schemes. It provides insights into the relationship between the numerical dissipation and grid resolution, and highlights the presence of numerical artifacts in the simulation of relativistic Kelvin-Helmholtz instability. The study suggests that high-order schemes may offer advantages in terms of accuracy and computational cost compared to low-order schemes, particularly on coarser grid resolutions in the presence of physical viscosity.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Computer Science, Interdisciplinary Applications
V. E. Ambrus, L. Bazzanini, A. Gabbana, D. Simeoni, S. Succi, R. Tripiccione
Summary: Relativistic kinetic theory is widely used in various fields of modern physics. It is important to develop efficient computational methods to accurately study relativistic fluid dynamics.
NATURE COMPUTATIONAL SCIENCE
(2022)
Article
Astronomy & Astrophysics
Santabrata Das, Anuj Nandi, Vivek K. Agrawal, Indu Kalpa Dihingia, Seshadri Majumder
Summary: This paper develops a model formalism to study accretion flows around rotating black holes with radiative coolings, examining physical parameters of ULXs. By solving governing equations, shock-induced global accretion solutions are obtained, and quasi-periodic oscillation frequencies and disc luminosity are calculated for shock solutions, potentially explaining observed properties of IC 342 X-1.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
L. Gavassino
Summary: This article investigates a mixture of three independent chemical components undergoing two distinct chemical reactions, and finds that they can be regarded as a viscous fluid with bulk stress governed by a second-order differential equation that reproduces the Burgers model. By considering muons, it is shown that neutron star matter is indeed a bulk viscous fluid of Burgers type.
CLASSICAL AND QUANTUM GRAVITY
(2023)
Article
Physics, Multidisciplinary
Nahuel Miron Granese, Alejandra Kandus, Esteban Calzetta
Summary: Thermal and turbulent fluctuations play a significant role in relativistic fluids, and they can be translated into quantum field theory problems using the Martin-Siggia-Rose technique.
Article
Physics, Multidisciplinary
Fabio S. Bemfica, Marcelo M. Disconzi, Jorge Noronha
Summary: We present the first generalization of Navier-Stokes theory to relativity that satisfies multiple properties. These properties are accomplished using a generalization of Eckart's theory containing only the hydrodynamic variables.
Article
Water Resources
Fei Jiang, Jianhui Yang, Edo Boek, Takeshi Tsuji
Summary: The lattice Boltzmann method is used to study the viscous coupling effects in three-phase flows at pore scale. A parametric modification factor for conventional conductance model is proposed to estimate the viscous coupling effect, and machine learning technique is introduced to predict multi-phase permeability. Such data-driven approach can be extended to develop a more sophisticated pore network model for better prediction of transport properties considering viscous coupling effects.
ADVANCES IN WATER RESOURCES
(2021)
Article
Engineering, Ocean
Guillermo Chillcce, Ould el Moctar
Summary: This paper presents a systematic numerical study on the effects of viscosity on ship stability in shallow water. The results show that viscosity affects a ship's trim and becomes more significant with decreasing under keel clearance.
APPLIED OCEAN RESEARCH
(2022)
Article
Mechanics
Jiachen Zhao, Zhongzheng Wang, Yuantong Gu, Emilie Sauret
Summary: A hybrid numerical model based on the lattice Boltzmann method and finite difference method is developed to investigate the control of viscous fingering using electrohydrodynamics. The effects of electric field strength and direction, as well as fluid properties, on viscous fingering are studied extensively. It is found that a horizontal electric field can either promote or suppress viscous fingering, depending on the permittivity ratio and conductivity ratio. A phase diagram is established to characterize the interfacial morphologies under different electric field orientations and fluid properties.
Article
Astronomy & Astrophysics
Yan Liu, Ya-Wen Sun
Summary: In relativistic hydrodynamics, gapless modes can become topologically nontrivial by weakly breaking the conservation of energy momentum tensor in a specific way. This system has topological semimetal-like crossing nodes in the spectrum of hydrodynamic modes that require the protection of a special combination of translational and boost symmetries in two spatial directions. The nontrivial topology is confirmed by the existence of an undetermined Berry phase.
Article
Physics, Particles & Fields
Aleksandr Kovalenko, Andrei Leonidov
Summary: This article analyzes shock wave solutions in anisotropic relativistic hydrodynamics and describes a new phenomenon of angular deflection of the incident flow caused by the shock wave front related to anisotropy. The patterns of velocity and momentum transformation by the shock wave front are also described.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
D. Huber, R. Kissmann
Summary: The study introduces the special relativistic extension of the CRONOS code for gamma-ray binary studies. The code is easily adaptable with support for various coordinates and designed with stability in mind.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Alessandro Lupi
Summary: The detection of gravitational waves has opened up a new era in astronomy, allowing for the direct study of compact objects using the combined information from gravitational wave and electromagnetic emissions. The current theoretical modeling mainly relies on standard numerical techniques, with limited exploration of new methods. In this study, we introduce a general relativistic extension to the mesh-less hydrodynamic scheme, which preserves angular momentum and demonstrates excellent performance in benchmark tests and the preservation of equilibrium solutions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Physics, Multidisciplinary
Giorgio Torrieri
ACTA PHYSICA POLONICA B
(2012)
Article
Physics, Multidisciplinary
Giorgio Torrieri
ACTA PHYSICA POLONICA B
(2012)
Article
Physics, Nuclear
Vincenzo Greco, Michael Mitrovski, Giorgio Torrieri
Article
Physics, Nuclear
Stefano Lottini, Giorgio Torrieri
Article
Physics, Nuclear
Giorgio Torrieri
Article
Astronomy & Astrophysics
Giorgio Torrieri
Article
Physics, Multidisciplinary
Giorgio Torrieri, Sascha Vogel, Bjorn Baeuchle
PHYSICAL REVIEW LETTERS
(2013)
Article
Physics, Multidisciplinary
Piotr Bozek, Wojciech Broniowski, Giorgio Torrieri
PHYSICAL REVIEW LETTERS
(2013)
Article
Physics, Nuclear
G. Torrieri, I. Mishustin
PHYSICS OF ATOMIC NUCLEI
(2012)
Article
Physics, Particles & Fields
Giorgio Torrieri
Summary: The study utilizes the Crooks fluctuation theorem and Zubarev hydrodynamics to develop a bottom-up theory of hydrodynamic fluctuations, and estimates bottom-up limits to dissipative transport coefficients using thermodynamic uncertainty relations.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Giorgio Torrieri, Henrique Truran
Summary: The discussion of the strong CP problem in the context of quantum field theory with horizons highlights the constraints that general covariance places on the topological structure of the theory. This could potentially offer a solution to the strong CP problem without the need for additional observable dynamics.
CLASSICAL AND QUANTUM GRAVITY
(2021)
Article
Physics, Multidisciplinary
Travis Dore, Lorenzo Gavassino, David Montenegro, Masoud Shokri, Giorgio Torrieri
Summary: Different formulations of hydrodynamics are related to uncertainties in the definitions of local thermodynamic and hydrodynamic variables. This ambiguity can be resolved by viewing different formulations of hydrodynamics as particular gauge choices.
Proceedings Paper
Instruments & Instrumentation
Giorgio Torrieri, Stefano Lottini
11TH INTERNATIONAL CONFERENCE ON SYNCHROTRON RADIATION INSTRUMENTATION (SRI 2012)
(2013)
Proceedings Paper
Physics, Particles & Fields
Giorgio Torrieri
RESONANCE WORKSHOP AT UT AUSTIN
(2012)
Proceedings Paper
Physics, Particles & Fields
Stefano Lottini, Giorgio Torrieri
INTERNATIONAL MEETING EXCITED QCD
(2012)