  We propose a new method of studying a real-time canonical evolution of
field-theoretic systems with boundary coupling to a realistic heat bath. In the
free-field case the method is equivalent to an infinite extension of the system
beyond the boundary, while in the interacting case the extension of the system
is done in linear approximation. We use this technique to study kink-antikink
dynamics in $\varphi^4$ field theory in 1+1 dimensions.

High Energy Physics - Lattice;Condensed Matter;High Energy Physics - Theory