In this work we show explicitly how to determine the Green functions for the calculation of the Casimir force due to scalar fields between boundaries represented by two Dirac delta functions in 1+1 dimensions. With this purpose, we re-obtain the K.A. Milton results (J. Phys. A37, 209 (2004)), showing in the detailed form the calculations of the Green functions.
Casimir forces; Dirac delta potentials; Green functions in 1+1 dimensions