SciPost logo

The complete scientific publication portal
Managed by professional scientists
For open, global and perpetual access to science

Sigma models on flags

Kantaro Ohmori, Nathan Seiberg, Shu-Heng Shao

SciPost Phys. 6, 017 (2019) · published 4 February 2019


We study (1+1)-dimensional non-linear sigma models whose target space is the flag manifold $U(N)\over U(N_1)\times U(N_2)\cdots U(N_m)$, with a specific focus on the special case $U(N)/U(1)^{N}$. These generalize the well-known $\mathbb{CP}^{N-1}$ model. The general flag model exhibits several new elements that are not present in the special case of the $\mathbb{CP}^{N-1}$ model. It depends on more parameters, its global symmetry can be larger, and its 't Hooft anomalies can be more subtle. Our discussion based on symmetry and anomaly suggests that for certain choices of the integers $N_I$ and for specific values of the parameters the model is gapless in the IR and is described by an $SU(N)_1$ WZW model. Some of the techniques we present can also be applied to other cases.

Authors/Affiliation: mappings to Contributors and Organizations
Funders for the research work leading to this publication