Two-dimensional Yang-Mills theory: perturbative and instanton contributions, and its relation to QCD in higher dimensions

Abstract

Two different scenarios (light-front and equal-time) are possible for Yang-Mills theories in two dimensions. The exact $\bar{q}q$-potential can be derived in perturbation theory starting from the light-front vacuum, but requires essential instanton contributions in the equal-time formulation. In higher dimensions no exact result is available and, paradoxically, only the latter formulation (equal-time) is acceptable, at least in a perturbative context.

latex 10 pages, no figures. Plenary session talk at the Meeting ``Constrained dynamics and quantum gravity 99'', Villasimius (Sardinia-Italy) September 13-17, 1999; minor changes

References in corpus (3)

• Two-dimensional QCD, instanton contributions and the perturbative Wu-Mandelstam-Leibbrandt prescription
• Instanton contributions to Wilson loops with general winding number in two dimensions and the spectral density
• Time exponentiation of a Wilson loop for Yang-Mills theories in 2+εdimensions

Cited by in corpus (5)

• The effects of Gribov copies in 2D gauge theories
• Perturbative Wilson loop in two-dimensional non-commutative Yang-Mills theory
• Quantum 't Hooft loops of SYM N=4 as instantons of YM_2 in dual groups SU(N) and SU(N)/Z_N
• Wilson Loop Area Law for 2D Yang-Mills in Generalized Axial Gauge
• Wilson loops in the adjoint representation and multiple vacua in two-dimensional Yang-Mills theory