Linking the scales in astro-plasma physics

• Grant number: 25/13918-3
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: March 01, 2026
• End date: March 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Astrophysics of the Interstellar Medium
• Principal Investigator: Elisabete Maria de Gouveia Dal Pino
• Grantee: Elisabete Maria de Gouveia Dal Pino
• Visiting researcher: Martin Karl Wilhelm Pohl
• Visiting researcher institution: University of Potsdam, Germany
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 21/02120-0 - Investigation of high energy and plasma astrophysics phenomena, installation of the ASTRI-Mini Array & construction of the Cherenkov Telescope Array Small Size Telescopes (CTA-SSTs), AP.ESP

Abstract

The Universe is filled with energetic charged particles known as cosmic rays that can reach energies more than a million times higher than is possible to attain in our laboratories, for example the LHC at CERN. Where and how cosmic rays are produced in the Galaxy is an important question in modern physics. Matter in space, and cosmic rays in particular, is collisionless, meaning that the internal energy distribution is shaped by collective wave-particle interactions with electromagnetic turbulence of various scales. Whereas the cosmic systems that harbor cosmic rays are often many light-years in size, the plasma waves with which cosmic rays interact have wavelengths as small as light-milliseconds, about ten orders of magnitude smaller than the objects in which they operate. There is not a single theoretical technique that can describe collisionless matter simultaneously on all spatial scales.The host, Prof. Elisabete de Gouveia Dal Pino, has performed many numerical simulations of particle-acceleration processes with techniques that work best at intermediate or large spatial scales, whereas the visitor, Prof. Martin Pohl, has conducted many simulations of small-scale phenomena. Both have employed numerical and semi-analytic methods to estimate the radiation products of particle acceleration and transport.The goal of Martin Pohl's visit at USP is to spawn of a direct and lasting collaboration between the research groups of Prof. de Gouveia Dal Pino and Prof. Pohl. Scientifically, the focus of the joint research activity would be the development of methods that help coupling the techniques on small, medium, and global scales. The visit at USP can therefore lay the foundation to a long-term cooperation with which major progress can be made toward a multi-scale description of astrophysical plasmas and energetic particle therein.For that purpose, we have devised a work plan composed of four steps:1) Listing for each computational technique and scientific application the needs for information input from larger or smaller scales, and likewise establishing the information that the technique in question can provide for studies optimized for other ranges of scales.2) Finding the matches, in which two techniques can give each other what they mutually need. These would constitute potential future projects for which we rank the estimated work load.3) Commencing work on the most simple application while the visitor is still at USP.4) Defining a plan to address the more complex applications in the future, including the exploration of funding options for students who would be involved in this research. (AU)