This paper follows up on a previous study showing that in an open atmosphere such as the solar corona the total magnetic helicity of a force-free field must be bounded and the accumulation of magnetic helicity in excess of its upper bound would initiate a non-equilibrium situation resulting in an expulsion such as a coronal mass ejection (CME). In the current paper, we investigate the dependenc...

We study the thermally activated motion of semiflexible polymers in double-well potentials using field-theoretic methods. Shape, energy, and effective diffusion constant of kink excitations are calculated, and their dependence on the bending rigidity of the semiflexible polymer is determined. For symmetric potentials, the kink motion is purely diffusive whereas kink motion becomes directed in t...

Bending with high curvature is one of the major mechanical properties of double-stranded DNA (dsDNA) that is essential for its biological functions. The emergence of a kink arising from local melting in the middle of dsDNA has been suggested as a mechanism of releasing the energy cost of bending. Herein, we report that strong bending induces two types of short dsDNA deformations, induced by two...

Context. We quantitatively address the conjecture that magnetic helicity must be shed from Sun by eruptions launching coronal mass ejections in order to limit its accumulation each hemisphere. Aims. By varying ratio of guide and strapping field flux rope twist a parametric simulation study ejection approximately marginally stable force-free equilibria, different ratios self- mutual are set onse...

The presence of Kink-turns (Kt) at key functional sites in the ribosome (e.g., A-site finger and L7/L12 stalk) suggests that some Kink-turns can confer flexibility on RNA protuberances that regulate the traversal of tRNAs during translocation. Explicit solvent molecular dynamics demonstrates that Kink-turns can act as flexible molecular elbows. Kink-turns are associated with a unique network of...

We study the stability of a so-called kink profile for the one-dimensional Cahn– Hilliard problem on the real line. We derive optimal bounds on the decay to equilibrium under the assumption that the initial energy is less than three times the energy of a kink and that the initial Ḣ−1 distance to a kink is bounded. Working with the Ḣ−1 distance is natural, since the equation is a gradient flow w...

Magnetized laser-produced plasmas are central to many studies in laboratory astrophysics, inertial confinement fusion, and industrial applications. Here, we present the results of large-scale three-dimensional magnetohydrodynamic simulations dynamics a plasma expanding into transverse magnetic field with strength tens teslas. The show being confined by strong slender slab structured magnetized ...