Exotic Five-branes in Heterotic Supergravity

In string theory, there are many kinds of extended objects, “branes". Among them, the ones with non-trivial monodromies are known as exotic branes. The most famous example of this class of branes is the type IIB seven-brane. Another example is the five-dimensional object called exotic five-brane; the well-known one is the ''522-brane’’, which is a type II supergravity solution. In this work, we construct the exotic five-brane in Heterotic supergravity. The exotic brane is obtained by Heterotic T-duality, which includes non-zero gauge fields and alpha'-corrections, with Heterotic NS5-brane solution and we show that the exotic brane agrees with the solution found by the standard embedding of the type II 522-brane. The monodromy structure of the Heterotic exotic brane is confirmed by the extended generalized metric including non-zero gauge fields. We also show that the structure is same as the monodromy of type II 522 due to the standard embedding.