Grigorios Papigkiotis

Grigorios Papigkiotis is a PhD Candidate in the School of Physics at the Aristotle University of Thessaloniki (AUTh), Greece, where he is actively involved in the department’s high-level research in astrophysics. His doctoral research is focused on Data Analysis for Gravitational Wave Observations and has received funding support from the Hellenic Foundation for Research and Innovation (H.F.R.I.). Mr. Papigkiotis’s core scientific work is situated within Computational Astrophysics and Relativistic Gravity. His research specifically focuses on the properties of Neutron Stars (NSs), which are the ultra-dense remnants of supernova explosions. He contributes to addressing one of the major challenges in nuclear astrophysics: understanding the Equation of State (EoS) of the matter within a neutron star’s core, where densities far exceed those found in atomic nuclei. A key aspect of his work involves applying Machine Learning (ML) techniques, such as feed-forward neural networks and the SHapley Additive exPlanations (SHAP) method, to complex problems in gravitational physics. He co-authored papers proposing “deep” EoS-insensitive universal relations—relations between a star’s global parameters (like its moment of inertia, equatorial radius, and rotational frequency) that hold true regardless of the exact nuclear EoS. By achieving high accuracy in modeling these relations, particularly for rapidly rotating neutron stars, his research provides crucial insights that can be used to constrain the EoS using observational data from gravitational wave detectors like LIGO, Virgo, and KAGRA. He is a junior member of the Hellenic Astronomical Society (Hel.A.S).