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KIAS HEP seminars

A Physically Reasonable Galactic Potential via Symbolic Regression on Gaia DR3

by Dr Adam Kamoski (University of Massachusetts, Boston)

→ Asia/Seoul
Room 1423 (KIAS)

Room 1423 (KIAS)

Description

Title: A Physically Reasonable Galactic Potential via Symbolic Regression on Gaia DR3

Speaker: Adam Kamoski 

Abstract: The local dark matter density determines the strength of the signal expected in direct-detection experiments, yet published estimates from stellar motions disagree by more than their errors, and the most recent machine-learning analysis of Gaia data finds a local density consistent with zero. According to Jeans' theorem, a distribution function built from integrals of motion satisfies the collisionless Boltzmann equation (CBE) trivially for any choice of potential, so a search that simultaneously fits the distribution function and the potential to the CBE identifies neither. Our pipeline instead estimates the distribution function in isolation, linearizing the equation in terms of accelerations and allowing for direct measurement of the local force field, and then fits closed forms to that field via symbolic regression. Throughout, we find that the usable information lies not in the CBE residual but in the stellar number counts, the observable most distorted by survey selection. Along the vertical profile, our recovered potential agrees with the classical self-gravitating isothermal disc.