A note on $\sigma$-model with the target $S^n$
Mathematical Physics
2020-05-15 v1 math.MP
Abstract
Naively the Hilbert space of a sigma model has to be defined as an L^2 space of functions on the space of free loops of the target. This object is not well defined. In this note we study a finite-dimensional approximations L_N(S^n) of the free loops of the sphere S^n. Spaces L_N(S^n) are defined in terms of finite Fourier series. L_N(S^n) finite-dimensional but singular. We compute Riemann and Ricci curvatures of the smooth locus of this space and study Schr\"odinger operator in the case of L_1(S^n)
Cite
@article{arxiv.2005.06497,
title = {A note on $\sigma$-model with the target $S^n$},
author = {M. V. Movshev},
journal= {arXiv preprint arXiv:2005.06497},
year = {2020}
}