Cosmic rays (CRs) are a key agent shaping the evolution of a wide range of astrophysical systems, from star formation sites to galaxies and galaxy clusters. The influence‬‭ of‬‭ CRs‬‭ depends critically‬‭ on‬‭ the‬‭ physics‬‭ governing‬ CR transport. However, this physics‬‭ remains‬‭ poorly‬‭ constrained,‬‭ both‬‭ theoretically‬‭ and‬‭ observationally.

On the theoretical front, significant advances have been made in particle-in-cell simulations of CR transport, fluid simulations isolating key CR processes, and cosmological simulations incorporating physics-informed parameterizations of CR physics. From the observational perspective, new data from observatories operating across the full electromagnetic spectrum will advance our understanding of the role of CRs in shaping astrophysical systems. In the solar neighborhood, data from the Parker Solar Probe and Solar Orbiter offer unique insights into particle acceleration and transport in the solar wind. Complementing these efforts, laboratory plasma experiments are now accessing regimes relevant to CR transport, providing independent constraints.

The next decade is poised to revolutionize our understanding of the impact of CRs across a broad spectrum of astrophysical environments, from the solar wind to galaxy clusters. This conference will explore similarities and analogies between different physical regimes and techniques and the growing interdisciplinary connections between the plasma physics, turbulence, solar wind, interstellar medium, star formation, high-energy astrophysics, galaxy formation, and laboratory astrophysics communities.