Narrow Results

I give a brief review of advances in the strong interaction theory. This talk was delivered at the Conference in honor of Murray Gell-Mann's 80th birthday, 24–26 February 2010, Singapore.

In a model that supports both Abelian (Abrikosov–Nielsen–Olesen) and non-Abelian strings we analyze the parameter space to find examples in which these strings not only coexist but are degenerate in tension. We prove that both solutions are locally stable, i.e. there are no negative modes in the string background. The tension degeneracy is achieved at the classical level and is expected to be lifted by quantum corrections. The setup of the model, analogous to that of Witten's superconducting cosmic strings, had been extended to include non-Abelian strings previously [M. Shifman, Phys. Rev. D87, 025025 (2013), arXiv:1212.4823 [hep-th]].

I give a brief review of advances in the strong interaction theory. This talk was delivered at the Conference in honor of Murray Gell-Mann's 80th birthday, 24-26 February 2010, Singapore.

I give a broad review of novel phenomena discovered in certain Yang-Mills theories: non-Abelian strings and confined monopoles. Then I explain how these phenomena allow one to study strong dynamics of gauge theories in four dimensions from two-dimensional models emerging on the string world sheet.