As of now, there have been theoretical studies and discussions about the potential outcomes of such a merger, but detailed and comprehensive models are still in the early stages. The complexity of the interactions involved makes it a challenging scenario to simulate accurately.
The primary expected outcome is a massive release of energy due to matter-antimatter annihilation. This could result in the production of high-energy gamma rays, neutrinos, and possibly even the formation of a black hole if the energy is sufficient to overcome the neutron degeneracy pressure.
There are several challenges, including the need for highly accurate simulations of relativistic effects, strong gravitational fields, and the detailed physics of matter-antimatter interactions. Additionally, the computational resources required for such simulations are substantial, and our current understanding of certain physical processes may still be incomplete.
In a neutron star-neutron star merger, the primary interactions are governed by gravity and nuclear forces, leading to the formation of a hypermassive neutron star or a black hole, accompanied by gravitational waves and electromagnetic radiation. In contrast, a neutron star and anti-neutron star merger would involve significant matter-antimatter annihilation, resulting in a much more energetic and potentially more violent event.
Advancements in high-performance computing, improved theoretical models of matter-antimatter interactions, and more precise observations of astrophysical phenomena are needed. Additionally, advancements in particle physics and a deeper understanding of the fundamental forces at play in such extreme environments would significantly contribute to our ability to model and understand these mergers.