Numerical determination of the boundary condition changing operators

A new numerical method to determine the boundary condition changing (bcc) operators in the boundary conformal field theory (BCFT) is introduced. This method is based on a variant of Schramm-Loewner Evolution (SLE), namely SLE(κ,ρ). As a prototype, the Abelian Sandpile Model (ASM) with a sink point on the boundary is considered. Using this method we study the bcc operator corresponding to the sink in the boundary of c=−2 BCFT. It is numerically shown that the conformal dimension of this operator is nearly 0. The most appropriate candidate for this operator is the logarithmic partner of the unity operator, i. e. Ĩ≡:θθ̄: as it has been conjectured theoretically.