activity
20112026
most citedSuperflare occurrence and energies on G-, K- and M-type dwarfs

105 citations · 603 across the 22 of their papers we have counts for

collaborators

22 papers

physics.flu-dyn2026

No evidence of vorticity production from irrotational turbulent gravitational collapse yet

Axel Brandenburg, Evangelia Ntormousi, Jennifer Schober

Gravitational collapse creates large amounts of kinetic energy that could potentially seed turbulence. If such turbulence were also suitable to initiate dynamo action, the resultin…

physics.flu-dyn2025★ 2 cited

Magnetically assisted vorticity production in decaying acoustic turbulence

Axel Brandenburg, Evan Scannapieco

We study vorticity production in isothermal, subsonic, acoustic (nonvortical), and decaying turbulence due to the presence of magnetic fields. Using three-dimensional numerical sim…

physics.flu-dyn2025★ 2 cited

Theory of the kinetic helicity effect on turbulent diffusion of magnetic and scalar fields

Igor Rogachevskii, Nathan Kleeorin, Axel Brandenburg

Kinetic helicity is a fundamental characteristics of astrophysical turbulent flows. It is not only responsible for the generation of large-scale magnetic fields in the Sun, stars,…

physics.flu-dyn2025★ 3 cited

Helicity effect on turbulent passive and active scalar diffusivities

Axel Brandenburg, Petri J. Käpylä, Igor Rogachevskii +1

Turbulent flows are known to produce enhanced effective magnetic and passive scalar diffusivities, which can fairly accurately be determined with numerical methods. It is now known…

astro-ph.SR2019★ 8 cited

Magnetic helicity and fluxes in an inhomogeneous alpha squared dynamo

A. Brandenburg

Much work on turbulent three-dimensional dynamos has been done using triply periodic domains, in which there are no magnetic helicity fluxes. Here we present simulations where the…

physics.plasm-ph2018★ 25 cited

Chiral fermion asymmetry in high-energy plasma simulations

Jennifer Schober, Axel Brandenburg, Igor Rogachevskii

The chiral magnetic effect (CME) is a quantum relativistic effect that describes the appearance of an additional electric current along a magnetic field. It is caused by an asymmet…

physics.flu-dyn2018★ 14 cited

Energetics of turbulence generated by chiral MHD dynamos

Jennifer Schober, Axel Brandenburg, Igor Rogachevskii +1

An asymmetry in the number density of left- and right-handed fermions is known to give rise to a new term in the induction equation that can result in a dynamo instability. At high…

physics.flu-dyn2015★ 46 cited

Large-scale flow generation by inhomogeneous helicity

Nobumitsu Yokoi, Axel Brandenburg

The effect of kinetic helicity (velocity--vorticity correlation) on turbulent momentum transport is investigated. The turbulent kinetic helicity (pseudoscalar) enters the Reynolds…

astro-ph.SR2014★ 102 cited

Magnetically controlled stellar differential rotation near the transition from solar to anti-solar profiles

Bidya Binay Karak, Petri J. Kapyla, Maarit J. Kapyla +3

Late-type stars rotate differentially owing to anisotropic turbulence in their outer convection zones. The rotation is called solar-like (SL) when the equator rotates fastest and a…

astro-ph.SR2014★ 105 cited

Superflare occurrence and energies on G-, K- and M-type dwarfs

Simon Candelaresi, Andrew Hillier, Hiroyuki Maehara +2

Kepler data from G-, K- and M-type stars are used to study conditions that lead to superflares with energies above . From the 117,661 stars included, 380 show su…

astro-ph.SR2014★ 33 cited

Intense bipolar structures from stratified helical dynamos

Dhrubaditya Mitra, A. Brandenburg, N. Kleeorin +1

We perform direct numerical simulations of the equations of magnetohydrodynamics with external random forcing and in the presence of gravity. The domain is divided into two parts:…

astro-ph.SR2013★ 14 cited

Magnetic flux concentrations in a polytropic atmosphere

I. R. Losada, A. Brandenburg, N. Kleeorin +1

Strongly stratified hydromagnetic turbulence has recently been identified as a candidate for explaining the spontaneous formation of magnetic flux concentrations by the negative ef…

astro-ph.HE2013★ 87 cited

Microphysics of cosmic ray driven plasma instabilities

A. M. Bykov, A. Brandenburg, M. A. Malkov +1

Energetic nonthermal particles (cosmic rays, CRs) are accelerated in supernova remnants, relativistic jets and other astrophysical objects. The CR energy density is typically compa…

astro-ph.SR2013★ 1 cited

Topological constraints in magnetic field relaxation

Simon Candelaresi

Stability and reconnection of magnetic fields play a fundamental role in natural and man-made plasma. In these applications the field's topology determines the stability of the mag…

astro-ph.SR2013★ 16 cited

Surface flux concentrations and spherical alpha-square dynamo

Sarah Jabbari, Axel Brandenburg, Nathan Kleeorin +2

In the presence of strong density stratification, turbulence can lead to a large-scale instability of a horizontal magnetic field if its strength is in a suitable range (within a f…

astro-ph.SR2012★ 2 cited

Topological constraints on magnetic field relaxation

Simon Candelaresi, Axel Brandenburg

Magnetic field relaxation is determined by both the field's geometry and its topology. For relaxation processes, however, it turns out that its topology is a much more stringent co…

astro-ph.SR2012★ 20 cited

Competition of rotation and stratification in flux concentrations

I. R. Losada, A. Brandenburg, N. Kleeorin +1

In a strongly stratified turbulent layer, a uniform horizontal magnetic field can become unstable to spontaneously form local flux concentrations due to a negative contribution of…

astro-ph.SR2012★ 18 cited

Rotational effects on the negative magnetic pressure instability

Illa R. Losada, A. Brandenburg, N. Kleeorin +2

The surface layers of the Sun are strongly stratified. In the presence of turbulence with a weak mean magnetic field, a large-scale instability resulting in the formation of non-un…

astro-ph.SR2012★ 5 cited

The alpha-effect in a turbulent liquid-metal plane Couette flow

G. Ruediger, A. Brandenburg

We calculate the mean electromotive force in plane Couette flows of a nonrotating conducting fluid under the influence of a large-scale magnetic field for driven turbulence. A vert…

astro-ph.SR2011★ 24 cited

Oscillatory large-scale dynamos from Cartesian convection simulations

P. J. Käpylä, M. J. Mantere, A. Brandenburg

We present results from compressible Cartesian convection simulations with and without imposed shear. In the former case the dynamo is expected to be of type which i…

astro-ph.SR2011★ 31 cited

Properties of the negative effective magnetic pressure instability

K. Kemel, A. Brandenburg, N. Kleeorin +1

As was demonstrated in earlier studies, turbulence can result in a negative contribution to the effective mean magnetic pressure, which, in turn, can cause a large-scale instabilit…

astro-ph.SR2011★ 45 cited

Negative effective magnetic pressure in turbulent convection

P. J. Käpylä, A. Brandenburg, N. Kleeorin +2

We investigate the effects of weakly and strongly stratified turbulent convection on the mean effective Lorentz force, and especially on the mean effective magnetic pressure. Earli…