[en] Gamma-Ray Bursts (GRBs) are among the most energetic transients in the Universe and candidate sources of Ultra-High-Energy Cosmic Rays (UHECRs). A clear confirmation from UHECR measurements is however challenging, as the directional information of cosmic rays is partially lost due to deflection by (inter-)galactic magnetic fields. In this dissertation we follow an alternative multi-messenger approach, in which the presence of UHECRs in an astrophysical object is indicated by neutrino or photon signatures produced in nuclear interactions. For this, we simulate GRBs in the multi-zone internal shock model, which accounts for different emission zones along the astrophysical jet and calculate nuclear interactions with state-of-the-art numerical codes. In this framework we discuss under which conditions the population of GRBs can still account for UHECR measurements while obeying current neutrino limits that stem from the lack of detected High-Energy (HE) neutrinos which could be associated with known GRBs. These neutrino limits may alternatively be met in low-luminosity objects, which typically have low neutrino production efficiency. We present leptonic radiation models of the sub-class of low-luminosity GRBs, with a focus on Very-High-Energy (VHE) emission potentially observable by current/future instruments. Connecting to UHECRs, we determine maximal energies of different cosmic-ray nuclei. The presence of nuclei may also be indicated by multi-wavelength signatures in the photon spectrum. We explore this approach in lepto-hadronic models of high-luminosity bursts, where we also critically review the conditions necessary to reproduce typical GRB spectra within our model.

[en] Because of their high luminosities, Gamma-Ray Bursts are considered possible sources of Ultra High Energy Cosmic Rays (UHECR) and high energy neutrinos. In the fireball internal shock scenario, the prompt high energy emission is generated in collisions between regions of the jet with different Lorentz factors. In this talk, I discuss the production of multiple astrophysical messengers within the internal shock scenario while including different models on the collision process.

[en] Due to the large amounts of energy they release, the extremely luminous transients called Gamma-Ray Bursts (GRBs) are of great interest for high energy astroparticle physics. In the fireball internal shock scenario, particle acceleration occurs in collisions between regions of the jet with different Lorentz factors. Usually, the observed prompt emission is attributed to synchrotron emission from accelerated electrons. However, if cosmic rays (baryons and nuclei of high energies) are contained in the outflow, they will be co-accelerated with electrons and might produce signatures in the electromagnetic spectrum. Besides, their interactions with the present photon fields will lead to the production of secondary neutrinos. In this talk, I discuss the production of multiple astrophysical messengers within the internal shock scenario, focussing on the constraints on cosmic ray production that come from neutrino and gamma-ray observations.

[en] We discuss the production of multiple astrophysical messengers (neutrinos, cosmic rays, gamma-rays) in the Gamma-Ray Burst (GRB) internal shock scenario, focusing on the impact of the collision dynamics between two shells on the fireball evolution. In addition to the inelastic case, in which plasma shells merge when they collide, we study the Ultra Efficient Shock scenario, in which a fraction of the internal energy is re-converted into kinetic energy and, consequently, the two shells survive and remain in the system. We find that in all cases a quasi-diffuse neutrino flux from GRBs at the level of 10${}^{-<!--\; ???\; -->11}$ to 10${}^{-<!--\; ???\; -->10}$GeV cm${}^{-<!--\; ???\; -->2}$ s${}^{-<!--\; ???\; -->1}$sr${}^{-<!--\; ???\; -->1}$ (per flavor) is expected for protons and a baryonic loading of ten, which is potentially within the reach of IceCube-Gen2. The highest impact of the collision model for multi-messenger production is observed for the Ultra Efficient Shock scenario, that promises high conversion efficiencies from kinetic to radiated energy. However, the assumption that the plasma shells separate after a collision and survive as separate shells within the fireball is found to be justified too rarely in a multi-collision model that uses hydrodynamical simulations with the PLUTO code for individual shell collisions.