Ludvig Doeser

On the hunt for answers to the bigger questions

I am a PhD student in cosmology at Stockholm University supervised by Prof. Jens Jasche. My research focuses on reconstructing the primordial density fluctuations of the Universe through field-level inference. By combining Bayesian forward modeling with modern machine learning, I develop methods to recover the initial conditions of cosmic structure formation from galaxy survey data. Recently, I have introduced neural network–based emulators into the BORG inference framework and proposed a gradient-free approach, LULO, which uses deep learning as a neural optimizer for fitting non-differentiable cosmological simulators to data. I am an active member of the Aquila Consortium and the Simons Collaboration on Learning the Universe, and I have recently been awarded a pre-doctoral fellowship at the Center for Computational Astrophysics in New York, where I will join as a Research Analyst in spring 2026.

The important thing is not to stop questioning. Curiosity has its own reason for existence. One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of this mystery each day.