Recent observations from the James Webb Space Telescope have transformed our view of Cosmic Dawn, revealing that the early Universe was far more diverse than expected just a few hundred million years after the Big Bang. Surprisingly abundant and UV-bright galaxies, chemically extreme systems, and numerous massive black holes powering active galactic nuclei are already in place at $z>6$ and beyond. These findings challenge pre-JWST theoretical expectations and highlight the need for revised models of early structure formation.
A key difficulty, however, lies in the interpretation of these observations. Extracting physical properties from photometric and spectroscopic data requires sophisticated modeling frameworks that connect observables to underlying galaxy physics. This includes spectral energy distribution (SED) fitting tools, which play a central role in interpreting James Webb Space Telescope data by inferring stellar populations, star formation histories, metallicities, or dust properties. Yet, they rely on assumptions that can introduce significant degeneracies and systematic uncertainties, particularly in the poorly constrained regime of the early Universe.
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An alternative route to interpreting high-redshift observations is through cosmological and galaxy simulations that incorporate the relevant physical processes and are forward-modelled into observational space. However, this approach is equally challenging: it requires accurate modeling of baryonic physics across a vast dynamic range, consistent treatment of radiative transfer and dust, and realistic synthetic observations that faithfully reproduce instrumental effects and selection biases.
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This conference aims to bring together theorists and observers to address these challenges in interpreting high-redshift data. By fostering collaboration between experts in simulations, spectral modeling and observations we seek to develop more robust and physically consistent approaches to interpreting high-redshift data. Key science questions to be addressed include:
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What physical mechanisms enabled the rapid formation of stars and massive black holes in the first few hundred million years?


How did feedback processes regulate these phenomena, partly leading to very mature and quenched galaxies already at z~6?


How robust are current inferences from SED fitting tools, and how can their assumptions be improved?


Are current tensions between observations and models indicative of missing physics, or of limitations in how we interpret the data?


How can simulations be more directly connected to observables, for example through realistic synthetic spectra and photometry?


How can we best combine data from JWST and other facilities, such as ALMA, within a coherent modeling framework?

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By focusing on these questions, the meeting will aim to clarify the most pressing puzzles of the early Universe and to establish a roadmap for progress toward a unified framework linking theory, spectral modeling, and observations.