Dr. Leonardos Gkouvelis, researcher at LMU's University Observatory Munich and member of the ORIGINS Excellence Cluster, has solved a fundamental mathematical problem that had obstructed the interpretation of exoplanet atmospheres for decades. In a paper published in The Astrophysical Journal, Gkouvelis presents the first closed-form analytical theory of transmission spectroscopy that accounts for how atmospheric opacity varies with pressure—an effect that is crucial in the scientific exploration of real atmospheres but had until now been considered mathematically intractable.