Comment on "Langmuir oscillations in a nonextensive electron-positron plasma".

Saberian and Esfandyari-Kalejahi [Phys. Rev. E 87, 053112 (2013)10.1103/PhysRevE.87.053112] have discussed Langmuir oscillations in a q-nonextensive electron-positron plasma. However, some of the results obtained and the conclusions drawn in this paper are not appropriate. In Fig. 3 of the above mentioned paper, the authors have claimed that for certain values of nonextensivity parameter q the imaginary part of the frequency becomes positive, resulting in unstable oscillations. In this Comment we shall discuss the fact that the Landau damping rate of Langmuir oscillations in a q-nonextensive electron-positron plasma is negative and results in damped oscillations. We hope that this Comment will be helpful in providing a better picture of Langmuir oscillations in nonextensive electron-positron plasma.