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Polar coordinate (r, θ) for y, and the unit vectors (e r , e θ ) in (3.10).

Polar coordinate (r, θ) for y, and the unit vectors (e r , e θ ) in (3.10).

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We consider constructing the relativistic system of collective coordinates of a field theory soliton on the basis of a simple principle: The collective coordinates must be introduced into the static solution in such a way that the equation of motion of the collective coordinates ensures that of the original field theory. As an illustration, we appl...

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... in the y-space, the polar coordinate system (r = | y| = |x| , θ, ϕ) with z-axis in the Ω direction, u has the following decomposition in terms of the unit vectors e r = y/r and e θ (see Fig. ...

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... Thus, we undertake the exploration of the interaction chiefly via direct numerical simulations of the relevant field equation. An Appendix complements our computations with analytical considerations based on the variational technique known as the "collective coordinate approximation," which is widely used in various field-theoretic problems (see, e.g., [7,[25][26][27]30,[43][44][45][46][47][48][49][50]). We note, in passing, that other approaches have been used to interrogate long-range interactions, such as evaluating the field's potential energy at the center of mass of two superimposed (anti)kinks [51,52]. ...
... It is relevant to mention here that the ansatz in Eqs. (27) and (28) is suitable not only for direct numerical simulations, but also for collective coordinate approximations of the PDE dynamics [7,[25][26][27]30,[43][44][45][46][47][48][49][50]. In particular, one can use Eqs. ...
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