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Ioannis Dimitropoulos
People · Postdoctoral researcher

Ioannis Dimitropoulos

COSMOS group, Research Center for Astronomy and Applied Mathematics (RCAAM), Academy of Athens · Department of Physics, University of Patras

OSCARS · MEXANE
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Research

What he works on

Pulsars · machine learning

Pulsar magnetospheres with PINNs

He uses physics-informed neural networks to solve the ideal force-free magnetosphere of a pulsar directly in its steady state, including the fully 3D case of an inclined dipole rotator. The domain is split into open and closed field-line regions separated by an adjustable separatrix, so the current sheets are treated as interfaces rather than smeared over the grid. This resolves features such as the Y-point, which in the 3D solution lies well inside the light cylinder.

Black holes · radiation

Flares from plasmoids around Sgr A*

In a multi-loop GRMHD model of Sgr A* without a stable jet, he identifies current sheets and regions of strong magnetic turbulence and computes 230 GHz and 2.2 μm light curves from non-thermal particles. The near-infrared flares match the observed flare durations and spectral index behaviour, linking them to particle acceleration in plasmoid chains close to the black hole.

Black holes · energy

Energy extraction from black holes

He also studies how energy is extracted from spinning black holes, connecting the plasmoids and current sheets of the accretion flow to the energy budget of the jet.

Figures

From his papers

3D pulsar magnetosphere solution seen from above, with the light cylinder and the equatorial current sheet
The 3D steady-state magnetosphere of an inclined rotator (λ = 20°) seen from above. The yellow cylinder is the light cylinder and the pale undulating surface is the equatorial current sheet; the Y-point lies well inside the light cylinder. Dimitropoulos, Chaniadakis & Contopoulos 2026, A&A 705, A140, Fig. 4
The same 3D pulsar magnetosphere seen from the side
The same solution seen from the side, showing the undulating equatorial current sheet between the two polar-cap regions. Dimitropoulos, Chaniadakis & Contopoulos 2026, A&A 705, A140, Fig. 5
Magnetization, plasma beta and temperature maps with plasmoids near the black hole
Transient plasmoid formation near the black hole: magnetization σ, plasma β and P/ρ in the multi-loop GRMHD model of Sgr A*. Dimitropoulos, Nathanail, Petropoulou, Contopoulos & Fromm 2025, A&A 696, A36
Publications

Selected papers