Connections between cosmic-ray physics, gamma-ray data analysis and Dark Matter detection

Cosmic-ray (CR) physics has been a prolific field of research for over a century. The open problems related to CR acceleration, transport and modulation are deeply connected with the indirect searches for particle dark matter (DM). In particular, the high-quality gamma-ray data released by Fermi-LAT are under the spotlight in the scientific community because of a recent claim about a inner Galaxy anomaly: The necessity to disentangle the astrophysical emission due to CR interactions from a possible DM signal is therefore compelling and requires a deep knowledge of several non-trivial aspects regarding CR physics. I review all these connections in this contribution. In the first part, I present a detailed overview on recent results regarding modeling of cosmic-ray (CR) production and propagation: I focus on the necessity to go beyond the standard and simplified picture of uniform and homogeneous diffusion, showing that gamma-ray data point towards different transport regimes in different regions of the Galaxy; I sketch the impact of large-scale structure on CR observables, and - concerning the interaction with the Heliosphere - I mention the necessity to consider a charge-dependent modulation scenario. In the second part, all these aspects are linked to the DM problem. I analyze the claim of a inner Galaxy excess and discuss the impact of the non-trivial aspects presented in the first part on our understanding of this anomaly.