Dear All,

Can any one please explain me that what is the meaning of the "self induced potential" in nonlocal PT symmetric NLSE of the following form

iq(x,t)_t=q(x,t)_xx ± 2 q(x,t) q*(-x,t) q(x,t)

where * denotes the complex conjugation and q(x,t) is a complex valued function of the real variables.

In all the articles related with the above topic talk the same that the above equation is PT symmetric unless V(x,t)=V*(-x,t) where V(x,t)= q(x,t) q*(-x,t).

Please give the detailed explanation or the materials to understand the physics related with the above.

Thanks in advance,

Vinayagam