Discussions and synergies on astrophysical plasma with PIC simulations - Prague 2026 edition

Session

Presentations & discussions

29 Sept 2026, 14:30

Slov - "Sál V. Dvořáka: hlavní sál" - A/1.NP/10 (Slovanka)

Conveners

Presentations & discussions: Session I.a.

• Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

Presentations & discussions: Session I.b.

• Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

Presentations & discussions: Session II.a

• Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

Presentations & discussions: Session II.b

• Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

Presentations & discussions: Session II.c

• Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

Presentations & discussions: Session III.a.

• Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

Presentations & discussions: Session III.b

• There are no conveners in this block

Presentations & discussions: Session III.c

• Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

Presentations & discussions: Session IV.a

• Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

Presentations & discussions: Session IV.b

• Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

Presentations & discussions: Farewells + information for the hackathon

• Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

22. Welcome notes & logistics

Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

29/09/2026, 14:30

Simply setting the framework of this face-to-face meeting

13. Preliminary simulations of astrophysical double-shock structures

Michelle Tsirou (Institute of Physics of the Czech Academy of Sciences (FZU))

29/09/2026, 14:40

Preliminary discussion topic

TBD

27. Caviton-Driven Bremsstrahlung: A novel mechanism for fast radio bursts from magnetars

Anabella Teresa Araudo

29/09/2026, 15:10

Preliminary discussion topic

20. The Role of Bell Turbulence Driven by Proton Cosmic Rays on Electron Acceleration at Oblique Shocks

Karol Fulat (UW-Madison)

29/09/2026, 16:15

Shock acceleration is generally a highly coupled problem involving nonlinear interactions between thermal plasma, waves, and nonthermal particles called cosmic rays (CRs). Upstream of the shock, the super-Alfvénic drift of CR protons excites the nonresonant streaming (Bell) instability. These unstable modes can grow to nonlinear levels, generating strong turbulence that further impacts...

2. Nonthermal Particle Acceleration by Magnetic Pumping in Pulsating Plasmas

Dr Giuseppe Arrò (University of Wisconsin - Madison)

29/09/2026, 17:15

Preliminary discussion topic

We present a new "pulsating box" setup to investigate particle acceleration in high-beta plasmas undergoing compression-expansion cycles. Our fully kinetic simulations show that particles are efficiently accelerated by magnetic pumping, producing nonthermal energy distributions with power-law tails. Numerical results are in excellent agreement with a generalized maximum entropy model that we...

17. PIC simulations of shocks at novae

Dr Oleh Kobzar (Astronomical Observatory, Jagiellonian University, Kraków, Poland)

30/09/2026, 10:00

Preliminary discussion topic

Preliminary results of PIC-simulation of shocks at novae:
structure, turbulence, instabilities, particle acceleration.

19. Kinetic Study of Shock Formation in Protostellar Jets

Jakub Gazdoš

30/09/2026, 11:00

Preliminary discussion topic

Synchrotron radio emission has been detected from jet termination regions of young stars, indicating the presence of relativistic electrons. Non-thermal electrons are most probably accelerated through the Fermi I acceleration. However, thermal electrons in the jet are not energetic enough to traverse the shock. This brings up the need for an electron pre-acceleration mechanism. We perform...

26. Transition from Proton Cyclotron to Weibel Instabilities in Perpendicular Non-relativistic Shocks

Valentine Devos (Max Planck Institute for Plasma Physics)

30/09/2026, 13:15

Preliminary discussion topic

Using 2D3V fully kinetic PIC simulations, we investigate how the dominant ion-scale instability regime evolves with Alfvénic Mach number ($M_A = 8.6-23$). At low $M_A$ ($\lesssim10$), the proton cyclotron instability (PCI), driven by ion temperature anisotropy, dominates and is accompanied by whistler-mode waves excited by electron temperature anisotropy in the shock ramp. At high $M_A$...

1. Kinetic Simulations of moderate Relativistic Pair Shocks with Trace Ion Admixture

Mahmoud Alawashra (DESY)

30/09/2026, 14:15

Preliminary discussion topic

Relativistic collisionless shocks accelerate particles through collective wave-particle interactions. In pair plasmas, turbulence is self-generated via the Weibel instability, but its structure and efficiency depend sensitively on plasma composition and magnetization. We perform large-scale Particle-in-Cell (PIC) simulations to study relativistic pair shocks with a sub-percent ion admixture, a...

21. Nonthermal particle acceleration in shock-mediated relativistic plasma turbulence

Karol Fulat (UW-Madison)

30/09/2026, 15:45

Turbulence with sufficiently strong and compressive driving develop shocks, which influence the energy cascade and dissipation. The properties of collisionless shock-mediated turbulence remain poorly understood. Using PIC simulations, we find efficient particle acceleration, which may be relevant for modeling nonthermal emission from relativistic jets.

11. Kinetic simulations of oblique high-Mach number shocks propagating in Alfvenic turbulence

Eloise Moore (Uni Potsdam)

30/09/2026, 16:45

Preliminary discussion topic

Astrophysical collisionless shocks like that of supernova remants are efficient particle accelerators that require some pre-acceleration mechanism in order for electrons to participate in diffusive shock acceleration. Using the PIC code, THATMPI, we perform novel simulations of oblique non-relativistic high-Mach-number shocks propagating into an upstream containing pre-existing decaying...

28. Signatures of Weibel instability on Earth`s bow shock: MMS observations

Valentina Villaflor (Max Planck Institute for Plasma Physics)

01/10/2026, 10:45

Preliminary discussion topic

Collisionless shocks dissipate the incoming flow’s kinetic energy through collective plasma processes rather than particle collisions, and at supercritical Mach numbers this dissipation relies on the reflection of a fraction of the incoming ions back into the upstream region. The resulting counter-streaming of reflected and incoming ion populations can drive ion Weibel instability,...

23. Charge Accumulation in Rotating Black Hole Magnetospheres: A First-Principles Study

Farukh Abdulkhamidov (Silesian University in Opava)

01/10/2026, 13:15

Preliminary discussion topic

Whether a rotating black hole in an external magnetic field actually charges up to the theoretical Wald value has remained an open question with major implications for magnetospheric structure and particle acceleration. Using general-relativistic particle-in-cell simulations with self-consistent pair production, we evolve black holes of different spins from two opposite starting charges and...

4. Kinetic modeling of binary neutron star magnetospheres

Jan Benacek

01/10/2026, 14:15

Presentation

30. Energy partition in collisionless counter-streaming plasmas

Frederico Fiuza

01/10/2026, 16:00

Preliminary discussion topic

31. Mapping particle acceleration across collisionless shock parameter space

Marco Costa

01/10/2026, 16:20

Preliminary discussion topic

32. Data-driven anomalous resistivity models from kinetic simulations

João Biu

01/10/2026, 16:40

Preliminary discussion topic

25. Analytical time-dependent distribution functions for driven PIC simulations

Francisco Ley (University of Chile)

01/10/2026, 17:00

Preliminary discussion topic

We present analytical expressions for the evolution of a general, gyrotropic, relativistic distribution function (VDF) of a collisionless, uniform, magnetized plasma subject to external forcings in the form of density and magnetic field variations. By analytically solving the relativistic, time-dependent drift kinetic equation for a collisionless, uniform plasma, a solution is obtained in...

5. Particle acceleration and heating in a highly magnetized mildly relativistic shock

Gabriel Torralba Paz (Max Planck Institute for Plasma Physics)

02/10/2026, 10:00

Preliminary discussion topic

We demonstrate that magnetized mildly relativistic shocks may be efficient particle accelerators capable of accounting for the intense X-ray and gamma-ray emission observed in jets of active galactic nuclei (AGN).

We employ the particle-in-cell (PIC) method to investigate a mildly relativistic shock in a magnetized electron-ion plasma under two magnetic field configurations: an oblique...

24. Kinetic simulations of mildly relativistic weakly magnetized shocks in AGN jets

Artem Bohdan (Max Planck Institute for Plasma Physics)

02/10/2026, 11:00

Preliminary discussion topic

Plasma shock waves are among the most promising sites for efficient particle acceleration in extragalactic jets. In mildly relativistic electron–ion shocks, electrons can be heated to high Lorentz factors, providing a natural explanation for the large minimum electron energies often required to model the emission of BL Lac objects (Arbet-Engels et al. 2025). In this work, we present results...

18. THATMPI : the road to an updated main branch

Martin Pohl

02/10/2026, 13:30

Technical

Technical internal contribution of current and past THATMPI developpers

29. TBD

Frederico Fiuza, Joao Pedro Ferreira Biu, Marco Costa

Preliminary discussion topic

3 presentations covering :
- energy partition in shocks (temperature ratio and non-thermal particle acceleration efficiency)
- development of reduced data-driven models for collisionless shocks