2026/07/20 by Shan-Chi Huang · 1 voice
#nlin.SI #hep-th #math-ph #math.MP
Asymptotic equivalence between the quasi-Grammian and quasi-Wronskian representations of N-soliton solutions in the J-matrix formulation of the anti-self-dual Yang-Mills (ASDYM) equation is established up to a constant matrix factor. This formulation, known as the Yang equation, serves as the equation of motion of the four-dimensional Wess-Zumino-Witten (WZW4) model and is equivalent to the ASDYM equation. To visualize the solitonic behavior, the action density of the WZW4 model is evaluated for G=U(2), demonstrating that the quasi-Grammian and quasi-Wronskian representations exhibit the same asymptotic soliton profiles, while the phase shift factors associated with N-soliton collisions are obtained explicitly. Hence, by virtue of the particle-like nature of solitons, the two representations describe the same class of ASDYM N-soliton solutions. These solitons can be regarded as a four-dimensional analogue of KP/KdV-type multi-solitons in fluid dynamics, suggesting a possible connection between the ASDYM equation and higher-dimensional Sato theory. Exact quasi-Grammian N-soliton solutions are also presented for N≤4.