Numerical Proof of the Possibility of Stably Generating Axisymmetric Magnetic Fields via Simple Convection

抄録

The generation of celestial magnetic fields is thought to follow Cowling's theorem. However, in this study, we found a possibility that it does not follow this theorem. While Cowling's theorem examines the magnetic field generation conditions at a point on the Poloidal surface, this theory argues that phenomena at multiple points cooperate to generate a magnetic field. This paper highlights the shortcomings in Cowling's theorem as originally written. Since the magnetic field of celestial bodies occurs in the convection of an electrically conductive fluid, it is natural to assume that the magnetic field axis is the same as the convection axis or the axis of rotation. However, Cowling's theorem denies this assumption, instead stating that an axisymmetric magnetic field on the same axis does not stem from axisymmetric convection. By decomposing the term related to power generation (induction term) in the electromagnetic induction equation into multiple component terms (each term) with cylindrical coordinates, converting them to magnetic field energy, and integrating the area via numerical calculations, the possibility of increasing magnetic field energy, which is not mentioned in Cowling's original theorem, is revealed. The phenomena of multiple points on the Poloidal surface cooperate to generate a magnetic field is shown. Furthermore, the possibility of generating a stable magnetic field is shown from the perspective of energy supply. Therefore, Cowling's theorem should be considered controversial. If there is a magnetic field generation that does not follow this theorem, the direction of relational research will also change.