String-coupling constant and dilaton vacuum expectation value in string field theory

Abstract

In the first quantized approaches to strings, it is well known that the string-coupling constant is determined by the vacuum expectation value of the dilation field. This property, however, has never been demostrated within the framework of string field theory. An explicit reparametrization of the string field associated with the shifts of the dilaton vacuum expectation value and the string-coupling constant is constructed exhibiting the above property in the light-cone field theory of the closed bosonic string.