arXiv subjects

Habib Yousefi Dezdarani

Publications and source records attributed to Habib Yousefi Dezdarani.

3 recordsLinked to original sources

arXiv2026

Conformal prediction for uncertainties in the neutron star equation of state

We study uncertainties in the equation of state of neutron stars using conformal prediction as a distribution-free and model-agnostic method that provides coverage guarantees. In particular, we apply the Conformalized Quantile Regression (CQR) method to posterior samples calculated from Bayesian inference, creating reliable uncertainty bands without assuming a specific form of the underlying distribution. We first construct CQR bands using a polytropic equation of state and the Tolman-Oppenheimer-Volkoff equations. We then apply CQR as a postprocessing step to the posterior distribution of neutron star mass-radius relations provided by the NMMA collaboration and to quantum Monte Carlo calculations of pure neutron matter. In all cases, empirical coverage studies confirm the robustness of the method.

nucl-th↗

arXiv2026

Conformal prediction for uncertainties in nucleon-nucleon scattering

Conformal prediction is a distribution-free and model-agnostic uncertainty-quantification method that provides finite-sample prediction intervals with guaranteed coverage. In this work, for the first time, we apply conformal-prediction to generate uncertainty bands for physical observables in nuclear physics, such as the total cross section and nucleon-nucleon phase shifts. We demonstrate the method's flexibility by considering three scenarios: (i) a pointwise model, where expansion coefficients in chiral effective field theory are treated as random variables; (ii) a Gaussian-process model for the coefficients; and (iii) phase shifts at various energies and partial waves calculated using local interactions from chiral effective field theory. In each case, conformal-prediction intervals are constructed and validated empirically. Our results show that conformal prediction provides reliable and adaptive uncertainty bands even in the presence of non-Gaussian behavior, such as skewness and heavy tails. These findings highlight conformal prediction as a robust and practical framework for quantifying theoretical uncertainties.

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arXiv2019

Ferromagnetic Neutron Stars in Scalar-Tensor Theories of Gravity

Ferromagnetic spin ordering can take place in neutron stars. This phase transition alters the neutron star equation of state. Here, applying the scalar-tensor theories of gravity, we investigate the structure of neutron stars which are in the ferromagnetic phase. Considering the equation of state of ferromagnetic neutron matter with Skyrme-type interactions at zero temperature and using the scalar-tensor theories of gravity with sufficiently negative coupling constant, we explore the spontaneous scalarization in ferromagnetic neutron stars. In this regard, the mass versus the central density, the profiles of scalar field and mass and density, the central scalar field for different central densities, and the mass-radius relation of ferromagnetic neutron stars are presented. Moreover, we investigate the influences of the coupling constant on the scalarization of ferromagnetic neutron stars. The effects of the coupling constant on the critical densities of scalarization and the scalar charge of ferromagnetic neutron stars are also calculated. In addition, we study the maximum value of the coupling constant at which the spontaneous scalarization takes place presenting the influence of the neutron matter equation of state on this critical value.

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