Self-consistent micro-to-macro modeling of internal magnetic fields in neutron stars

Develop a fully self-consistent description of neutron-star internal magnetic fields that links microphysical inputs (composition, superconductivity/superfluidity, and inter-component couplings) to macroscopic field configurations and dynamics, providing a coherent model of the internal field geometry and structure.

Background

The paper reviews how strong magnetic fields affect dense matter and emphasizes that while mixed poloidal–toroidal configurations (twisted-torus geometries) are plausible, their stability and detailed structure depend on uncertain microphysics, including superconductivity and coupling between components.

Direct observations primarily constrain the external dipolar field, leaving the internal field strength and geometry—especially in the core—largely uncertain. The authors state that, despite qualitative or phenomenological modeling, a complete self-consistent framework connecting microphysics to global equilibria and observables remains lacking.

References

Consequently, magnetic-field effects can be incorporated at a qualitative or phenomenological level, but a fully self-consistent microphysical and macroscopic description is still an open problem.

— Spin effects in superfluidity, neutron matter and neutron stars  (2604.02782 - Sedrakian et al., 3 Apr 2026) in Section 3 (Spin and magnetic field)

It is difficult to determine whether this is due to the very slow convergence of the minimisation procedure, so that the shown configuration has not yet reached the true minimum, or whether the vortex has effectively exhausted its ability to attract additional fluxtubes.

— Fluxtube Bouquets and Type-1.5 Clustering in Superfluid Neutron Star Cores  (2608.25943 - Karekkat et al., 26 Aug 2026) in Section 5.3, “Fluxtube bouquets”

The evolution problem is further complicated by the fact that the initial configuration of the magnetic field is unknown, as its physical origin remains a subject of ongoing debate \citep{2006MNRAS.367.1323F,10.1063/1.2900262,2021Univ....7..351I}.

— Correlating Surface Magnetic Field Decay with Internal Field Depth of Isolated Neutron Stars  (2609.39428 - Sellick et al., 30 Sep 2026) in Section 1, Introduction

The long-term evolution of neutron star magnetic fields remains one of the open questions in pulsar astrophysics.

— Correlating Surface Magnetic Field Decay with Internal Field Depth of Isolated Neutron Stars  (2609.39428 - Sellick et al., 30 Sep 2026) in Section 1, Introduction

However, core composition is still uncertain and may include various superfluid, superconductive, or exotic phases.

— Correlating Surface Magnetic Field Decay with Internal Field Depth of Isolated Neutron Stars  (2609.39428 - Sellick et al., 30 Sep 2026) in Section 1, Introduction

The inclusion and detailed study of these effects are left for future work.

— Adiabatic evolution of hadronic neutron stars  (2610.13926 - Logoteta et al., 9 Oct 2026) in Section 6, Conclusions