Gravitational instantons and black plane solutions in four-dimensional string theory

ADRIAN R. LUGO

PHYSICAL REVIEW D

AMER PHYSICAL SOC

Lugar: New York; Año: 1995 vol. 52 p. 2266 - 2277

1550-7998

We consider gauged Wess-Zumino models based on the noncompact group SU(2,1). It is shown that by vector gauging the maximal compact subgroup U(2) the resluting backgrounds obey the gravity-dilaton one loop string vacuum equations of motion in four-dimensional Euclidean space. The torsionless solution is then interpreted as a pseudoinstanton of the d=4 Liouville theory coupled to gravity. The presence of a translational isometry in the model allows one to get another string vacuum background by using a target duality that we identify with those corresponding to the axial gauging. We also compute the exact backgrounds. Depending on the value of k, they may be interpreted as instantons connecting a highly singular big-bang-like universe with a static singular or regular black plane geometry.