Bayesian Inference of Neutron Star Properties in $f(Q)$ Gravity Using NICER Observations

Abstract: In this work, we investigate neutron stars (NSs) in the strong field regime within the framework of symmetric teleparallel $f(Q)$ gravity, considering three representative models: linear, logarithmic, and exponential. While Bayesian studies of NS observations are well established in General Relativity and curvature based modified gravity theories, such analyses in $f(Q)$ gravity remain largely unexplored. We perform a Bayesian inference analysis by confronting theoretical NS mass-radius predictions with NICER observations of PSR J0030+0451, PSR J0740+6620, PSR J0437+4715, and PSR J0614+3329. The dense matter equation of state is fixed to DDME2 in order to isolate the effects of modified gravity on NS structure. Our results show that the exponential $f(Q)$ model is statistically preferred over the linear and logarithmic cases, as confirmed by Bayes factor comparisons, and exhibits well-constrained. For this model, we obtain a radius and tidal deformability at $1.4\,M_\odot$ of $R_{1.4} = 11.27<sup>{+0.53}_{-0.36}\,\mathrm{km}$ and $$Λ<em>{1.4} = 156.95^{+84.02}</em>{-41.73}$$, respectively, consistent with current observational constraints. These results highlight the potential of NSs as powerful probes of symmetric teleparallel gravity in the strong field regime.