English
Related papers

Related papers: Supercriticality to subcriticality in dynamo trans…

200 papers

Bistability and hysteresis of magnetohydrodynamic dipolar dynamos generated by turbulent convection in rotating spherical fluid shells is demonstrated. Hysteresis appears as a transition between two distinct regimes of dipolar dynamos with…

Fluid Dynamics · Physics 2009-04-07 R. D. Simitev , F. H. Busse

We study the thermodynamic phase transition of a spin Hamiltonian comprising two 3D magnetic sublattices. Each sublattice contains XY spins coupled by the usual bilinear exchange, while spins in different sublattices only interact via…

Strongly Correlated Electrons · Physics 2010-09-29 Yoshitomo Kamiya , Naoki Kawashima , C. D. Batista

We investigate how the strength of the Lorentz force alters stellar convection zone dynamics in a suite of buoyancy-dominated, three-dimensional, spherical shell convective dynamo models. This is done by varying only the magnetic Prandtl…

Solar and Stellar Astrophysics · Physics 2025-08-28 Krista M. Soderlund , Paula Wulff , Petri Käpylä , Jonathan M. Aurnou

The dynamo instability is investigated in the limit of infinite magnetic Prandtl number. In this limit the fluid is assumed to be very viscous so that the inertial terms can be neglected and the flow is slaved to the forcing. The forcing…

Fluid Dynamics · Physics 2015-05-20 Alexandros Alexakis

We calculate the magnetization of a two-dimensional superconductor in a perpendicular magnetic field near its Kosterlitz-Thouless transition and at lower temperatures. We find that the critical behavior is more complex than assumed in the…

Superconductivity · Physics 2013-05-29 Vadim Oganesyan , David A. Huse , S. L. Sondhi

Using direct numerical simulations of three-dimensional hydromagnetic turbulence, either with helical or non-helical forcing, we show that the ratio of kinetic-to-magnetic energy dissipation always increases with the magnetic Prandtl…

Solar and Stellar Astrophysics · Physics 2014-07-25 Axel Brandenburg

Physics of supercritical state is understood to a much lesser degree compared to subcritical liquids. Carbon dioxide in particular has been intensely studied, yet little is known about the supercritical part of its phase diagram. Here, we…

For the understanding of planetary and stellar dynamos an overview of the major parameter dependences of convection driven dynamos in rotating spherical fluid shells is desirable. Although the computationally accessible parameter space is…

Fluid Dynamics · Physics 2009-04-29 F. H. Busse , R. D. Simitev

Superconducting transitions in the absence of magnetic field should be non-hysteretic. Here we address the fact that the drops in electrical resistance that have been interpreted as evidence of superconductivity in several hydrides under…

Superconductivity · Physics 2021-01-27 J. E. Hirsch , F. Marsiglio

We uncover a finite-time dynamical phase transition in the thermal relaxation of a mean-field magnetic model. The phase transition manifests itself as a cusp singularity in the probability distribution of the magnetisation that forms at a…

Statistical Mechanics · Physics 2022-03-23 Jan Meibohm , Massimiliano Esposito

Small-scale dynamos play important roles in modern astrophysics, especially on Galactic and extragalactic scales. Owing to dynamo action, purely hydrodynamic Kolmogorov turbulence hardly exists and is often replaced by hydromagnetic…

Astrophysics of Galaxies · Physics 2022-12-20 A. Brandenburg , I. Rogachevskii , J. Schober

The main goal of this paper is to understand the formation of hexagonal patterns from the dynamical transition theory point of view. We consider the transitions from a steady state of an abstract nonlinear dissipative system. To shed light…

Mathematical Physics · Physics 2020-08-26 Taylan Şengül

The self-excitation of magnetic field by a spiral Couette flow between two coaxial cylinders is considered. We solve numerically the fully nonlinear, three-dimensional MHD equations for magnetic Prandtl numbers Pm (ratio of kinematic…

Astrophysics · Physics 2009-11-06 Wolfgang Dobler , Anvar Shukurov , Axel Brandenburg

We study the off-equilibrium critical phenomena across a hysteretic first-order transition in disordered athermal systems. The study focuses on the zero temperature random field Ising model (ZTRFIM) above the critical disorder for spatial…

Statistical Mechanics · Physics 2023-01-16 Anurag Banerjee , Tapas Bar

Spin-crossover has a wide range of applications from memory devices to sensors. This has to do mainly with the nature of the transition, which may be abrupt, gradual or incomplete and may also present hysteresis. This transition alters the…

Strongly Correlated Electrons · Physics 2019-07-10 J. Quetzalcoatl Toledo-Marin , Carlos Rodriguez , Yosdel Plasencia Montesino , Gerardo G. Naumis

Small scale turbulent dynamo action in compressible transonic turbulence is discussed. It is shown that the critical value of the magnetic Reynolds number displays a bimodal behavior and changes from a typical value of 35 for small Mach…

Astrophysics · Physics 2007-05-23 A. Brandenburg , N. E. L. Haugen , A. J. Mee

A three-dimensional numerical computation of magnetohydrodynamic dynamo behavior is described. The dynamo is mechanically forced with a driving term of the Taylor-Green type. The magnetic field development is followed from negligibly small…

Astrophysics · Physics 2007-05-23 P. D. Mininni , Y. Ponty , D. C. Montgomery , J. -F. Pinton , H. Politano , A. Pouquet

Most large-scale planetary magnetic fields are thought to be driven by low Rossby number convection of a low magnetic Prandtl number fluid. Here kinematic dynamo action is investigated with an asymptotic, rapidly rotating dynamo model for…

Geophysics · Physics 2016-12-14 Michael A. Calkins , Louie Long , David Nieves , Keith Julien , Steven M. Tobias

Identifying generic physical mechanisms responsible for the generation of magnetic fields and turbulence in differentially rotating flows is fundamental to understand the dynamics of astrophysical objects such as accretion disks and stars.…

Astrophysics · Physics 2009-11-13 F. Rincon , G. I. Ogilvie , M. R. E. Proctor , C. Cossu

Experimental data from Maxwell's demon experiments on granular gas are revisited. It is shown that the transition nature changes from critical to sub-critical via a tri-critical point when frequency of vibration is increased continuously.…

Fluid Dynamics · Physics 2011-11-24 P. Evesque