The ΛCDM model has provided a robust framework for understanding the formation of structures in the Universe through the collapse of primordial density fluctuations. Despite its successes in describing the Universe on large scales, the ΛCDM model faces significant challenges on smaller scales, particularly in the context of galaxy halos. Key discrepancies include the core-cusp problem, the too-big-to-fail problem, and the missing satellites problem. These issues highlight the need for a deeper investigation into the nature of dark matter and the processes governing galaxy formation and evolution. In recent years, the advent of advanced observational tools and surveys has opened new avenues for studying low surface brightness phenomena and the outskirts of galaxies. Instruments such as the Vera C. Rubin Observatory's LSST, the Euclid mission, and the upcoming ARRAKIHS mission promise to provide unprecedented data on the structure and composition of the Universe's faintest regions. This symposium will focus on leveraging these data to test and refine theoretical models of galaxy formation. By examining tidal streams, stellar streams, and satellite galaxies, researchers can gain insights into the distribution and properties of dark matter. Tidal streams, remnants of disrupted satellite galaxies, serve as powerful probes of the gravitational potential of their host galaxies. Stellar streams, similarly, offer clues about the small-scale structure of dark matter. The symposium will cover recent discoveries in these areas and discuss their implications for our understanding of dark matter and galaxy formation.

The symposium will also address the results of deep surveys of satellite galaxies in the Local Group and beyond. These surveys have revealed unexpected structures, such as planes of satellite galaxies, that challenge the predictions of the ΛCDM model. Understanding the formation and dynamics of these structures is crucial for testing the validity of the current cosmological paradigm. In addition to observational studies, the symposium will explore the theoretical implications of new data. Researchers will discuss how simulations of galaxy formation can be adjusted to account for observed discrepancies and what these adjustments reveal about the fundamental properties of dark matter and baryonic processes.

Overall, the symposium aims to foster a comprehensive understanding of the processes that shape galaxies and the role of dark matter in their evolution. By bringing together leading experts in the field, the symposium will provide a forum for discussing the latest findings, identifying current challenges, and setting the stage for future research. Participants will have the opportunity to share their work, form new collaborations, and contribute to the advancement of our knowledge of the Universe.