A Parallel Transport Frame Field Approach to Soliton Surfaces associated with the Betchov-Da Rios Equation in Four Space
In the present paper, the geometric properties of a soliton surface $\Psi=\Psi(s,t)$ associated with the Betchov-Da Rios (B-DR) equation using the parallel transport frame field in four-dimensional Euclidean space are examined. We obtain the derivative formulas for the parallel transport frame field of a unit-speed $s$-parameter curve $\Psi=\Psi(s,t),$ for all $t$. We obtain the soliton surface's two basic geometric invariants, $k$ and $h,$ and some other important invariants such as Gaussian curvature, mean curvature vector and Gaussian torsion. With the aid of these, a set of theorems describing the conditions in which the soliton surface is flat, minimal, semi-umbilic or Wintgen ideal (superconformal) are proved using these surface invariants. Also, we give a theorem which characterizes the curvature ellipse of the B-DR soliton surface with respect to the parallel transport frame field in $E^{4}$. Finally, we construct an example of a B-DR soliton surface, obtain its geometric invariants and showed its projections into three-dimensional space to demonstrate our theoretical understanding.