Thermodynamics of Open Bosonic Strings in Background Fields

Vacuum instability in external fields

“…Finally, we believe that the formulas derived and the time-dimensional analysis presented can be also useful to describe some collective effects in the framework of quantum field theory, for instance, to describe multiple particles creation by means of the external field approach [13,14] or in string models with external field [11,12,41].…”

“…where ζ C are some normalization constants. Considering the asymptotic of the functions (41) at x 0 → −∞, (in this case F (a, b; c; y) = 1 [27]), one can verify that the relations (8) hold and…”

Mass eigenvalues of the open charged string in a magnetic background

“…It is quite likely that if the right string mass is used in the state density approach to derive the critical temperature, the disagreement between the results reported in Refs. [18] and [19] will be resolved finally. We have good reasons to believe that the results of Ref.…”

“…Recently it has been claimed that the partition function of the string gas in the presence of a magnetic field diverges when the magnetic field exceeds some critical value that depends on temperature [17]. The possible modification of the Hagedorn temperature due to a pure magnetic background seems to be more controversial [18,19].…”

“…[18]. However, the mass squared that was used there does not correspond to the Casimir operator of the group of global symmetries.…”