Speaker
Description
Neutron stars(NS) offer a unique cosmic laboratory to probe the nature of dark
matter (DM), one of the biggest open questions in physics. We study NS carrying a
small admixture of dark matter, modelling both ordinary (hadronic) matter and dark
matter using nuclear physics-based equations of state(EoS), and comparing two
possibilities: Fermionic versus Bosonic DM. Using Bayesian inference, we combine
current astrophysical data - pulsar mass-radius measurements from the NICER
mission and gravitational-wave data from the NS merger GW170817 - to constrain
DM properties such as its mass, coupling strength, and fraction inside the star. We
address two questions: (1) the way these observations are incorporated, does it
change the inferred DM parameters, and (2) can current data distinguish fermionic
from bosonic DM? We find the DM fraction (below ~10%) is the best-constrained
parameter regardless of method, while DM mass and coupling remain weakly
constrained. Crucially, present observations show no statistical preference between
fermionic and bosonic DM, meaning both remain equally viable - motivating future,
more precise measurements to resolve this question.