Supersymmetric Solitons and How They Help Us Understand Non-Abelian Gauge Theories
M. Shifman, A. Yung
TL;DR
The paper surveys how supersymmetry reveals BPS solitons—domain walls, vortices, and monopoles—and how their central charges constrain exact results at strong coupling. It develops three strands: non-Abelian strings with confined monopoles in N=2 theories, controlled reductions to N=1 and non-SUSY via the M model, and domain walls as D-brane prototypes with localized gauge fields and wall–string junctions. A key insight is the worldsheet realization: non-Abelian strings host CP(N−1) dynamics, with confined monopoles appearing as CP(N−1) kinks, and a deep 4D–2D correspondence (Seiberg–Witten in 4D mirrored by CP(N−1) structures in 2D). The work extends these ideas to less SUSY, clarifying when non-Abelian confinement persists and how infrared issues are resolved, thereby connecting gauge dynamics across dimensions and highlighting potential pathways toward understanding QCD-like confinement in non-supersymmetric theories.
Abstract
In the last decade it became clear that methods and techniques based on supersymmetry provide deep insights in quantum chromodynamics and other supersymmetric and non-supersymmetric gauge theories at strong coupling. In this review we summarize major advances in the critical (Bogomol'nyi-Prasad-Sommerfeld-saturated, BPS for short) solitons in supersymmetric theories and their implications for understanding basic dynamical regularities of non-supersymmetric theories. After a brief introduction in the theory of critical solitons (including a historical introduction) we focus on three topics: (i) non-Abelian strings in N=2 and confined monopoles; (ii) reducing the level of supersymmetry; and (iii) domain walls as D brane prototypes.
