Abstract: The origin and propagation of cosmic rays (CRs) is a multi-disciplinary problem in which plasma (astro)physics plays a major role. Plasma processes are indeed determining how these charged particles are injected and accelerated at their astrophysical sources, as well as the type of turbulence that CRs encounter as they propagate through different Galactic environments; cosmic-ray propagation itself is defined by plasma processes underlying their non-linear interaction with turbulence. More than a century after their discovery, our understanding of the processes yielding cosmic rays and defining their journey through the Galaxy cannot be considered satisfactory.In this talk, I will discuss how the most-recent direct and indirect CR measurements challenge the naive picture of cosmic-ray transport that is usually adopted by the astroparticle community, delving in what are the issues with a standard description of CR scattering based on Alfvénic fluctuations. I will also present recent results based on different approaches that may solve some of the typical issues, but that simultaneously lead to new open questions.
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