Tachyon and fixed scalars of D5$_\pm$-D1$_\pm$ black hole in type 0B string theory

Abstract

In the type 0B string theory, we discuss the role of tachyon($T$) and fixed scalars($ν,λ$). The issue is to explain the difference between tachyon and fixed scalars in the D$5_{\pm}$-D$1_{\pm}$ black hole background. For this purpose, we perform the semiclassical calculation. Here one finds a mixing between ($ν, λ, T$) and the other fields. Using the decoupling procedure, one finds the linearized equation for the tachyon. From the potential analysis, it turns out that $ν$ plays a role of test field well, while the tachyon induces an instability of Minkowski space vacuum. But the roles of $ν$ and $T$ are the same in the near-horizon geometry. Finally we discuss the stability problem.