标题： 轴子-引力子孤子 显示英文标题

标题： Solitons of axion-dilaton gravity

摘要： 我们使用二维约化β函数方程的孤子技术，从平空间获得非平凡的弦背景。 这些解由两个整数(n, m)表征，分别指度规和轴子-稀释子部分的孤子数。 我们证明，与SL(2) x SU(2) / SO(1, 1) x U(1) CFT商空间相关的Nappi-Witten宇宙以这种方式作为(1, 1)孤子出现，对于模参数的某些值，而当孤子模参数为其他值时，我们得到SL(2)/SO(1, 1) x SO(1, 1)^2背景。 普通的四维黑洞作为二维(2, 0)孤子出现，而欧几里得虫洞背景则被描述为平空间上的(0, 2)孤子。 孤子变换对应于弦Geroch群的特定元素。 这些可以作为探索U对偶性在二维弦紧化中作用的起点。 显示英文摘要

摘要： We use soliton techniques of the two-dimensional reduced beta-function equations to obtain non-trivial string backgrounds from flat space. These solutions are characterized by two integers (n, m) referring to the soliton numbers of the metric and axion-dilaton sectors respectively. We show that the Nappi-Witten universe associated with the SL(2) x SU(2) / SO(1, 1) x U(1) CFT coset arises as an (1, 1) soliton in this fashion for certain values of the moduli parameters, while for other values of the soliton moduli we arrive at the SL(2)/SO(1, 1) x SO(1, 1)^2 background. Ordinary 4-dim black-holes arise as 2-dim (2, 0) solitons, while the Euclidean worm-hole background is described as a (0, 2) soliton on flat space. The soliton transformations correspond to specific elements of the string Geroch group. These could be used as starting point for exploring the role of U-dualities in string compactifications to two dimensions.