NBIA Astroparticel Seminar: Isabelle John

(Stockholm University)

Spectral Features in the Cosmic-Ray Positron Flux -- The Dangers of Approximating a Stochastic Process as Continuous

High-energy cosmic-ray electrons and positrons lose energy rapidly as they propagate through the Galaxy, due to synchrotron interactions with magnetic fields and inverse-Compton scattering interactions with photons of the interstellar radiation field. Typically, these energy losses have been modelled as a continuous process. However, inverse-Compton scattering is a stochastic process, characterised by interactions that are rare and catastrophic. In this talk, I present results that take this stochasticity of inverse-Compton scattering into account. Compared to the continuous approximation, this leads to significant changes in the expected contribution from dark matter and pulsar sources, which may allow us to distinguish these sources with upcoming observations of the cosmic-ray electron and positron spectra.