Thermodynamics of a noncritical bosonic string

It is at present an obvious fact that string theory is extremely poorly understood at short distances, at which the extended structure of the strings plays a very important role. It is entirely possible that on scales comparable to the fundamental string length a completely new description of string theory is necessary. If this is so, it is natural to expect that the new string physics will be manifested in the study of the theory of strings under extreme conditions. In this connection, attempts have recently been undertaken to study the high-energy scattering of strings and the behavior of strings at high temperature and high energy density. In particular, in the description of string thermodynamics, approximations based both on the canonical and on the microcanonical ensemble have been developed, and this has clarified the role of the Hagedorn temperature as the critical temperature of the system. In the present paper the authors extend the investigation of the thermodynamic properties of a noncritical closed bosonic string on the background Md x TD-d both in the canonical and in the microcanonical ensemble