Year: 1994
Type: article
Abstract: Preliminary investigations are made for the stability of the 1/N expansion in three-dimensional gravity coupled to various matter fields, which are power-counting renormalizable. For unitary matters, a tachyonic pole appears in the spin-2 part of the leading graviton propagator, which implies an unstable flat space-time, unless the higher-derivative terms are introduced. As another possibility to avoid this spin-2 tachyon we propose Einstein gravity coupled to nonunitary matter. It turns out that a tachyon appears in the spin-0 or -1 part for any linear gauges in this case, but it can be removed if nonminimally coupled scalars are included. We suggest an interesting model which may be stable and may possess an ultraviolet fixed point.
Authors: Shun’ya Mizoguchi, Hisashi Yamamoto
Institutions: Universität Hamburg, Doshisha Women's College of Liberal Arts
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funder: Alexander von Humboldt-Stiftung
OpenAlex ID: W2032565328