Fission is the nuclear process by which a nucleus splits into fragments. Although this reaction was discovered nearly 90 years ago, it remains a major fundamental challenge, both experimentally, as data are difficult to obtain and interpret, and theoretically, as no existing model can yet simultaneously reproduce experimental results, provide reliable predictive power, and offer a consistent physical interpretation of the process.

Galaxy clusters are the end products of the hierarchical formation of structures in the universe in the ΛCDM paradigm. Despite their great masses, clusters are relatively young systems -- some of which are virialized, while others remain dynamically disturbed. Their late formation and large masses make clusters excellent probes of cosmology. Additionally, a wide variety of astrophysical processes in clusters shape their thermodynamic states and influence the evolution of galaxies. In this talk, I will first outline how clusters serve as a unique laboratory for exploring these processes.

String theory provides a consistent microscopic framework for gravity and the other fundamental interactions. However, the string-derived models that we understand best differ from our universe in a key aspect: they are spacetime supersymmetric. In this talk, I will introduce supersymmetry and discuss the role it plays in string theory, highlighting the challenges that arise when supersymmetry is broken—both from formal and phenomenological perspectives.