  A recent paper by Alves, Das, and Perez contains a calculation of the
one-loop self-energy in \phi^{3} field theory at T\neq 0 using light-front
quantization and concludes that the self-energy is different than the
conventional answer and is not rotationally invariant. The changes of variables
displayed below show that despite the complicated appearance of the thermal
self-energy in light-front variables, it is exactly the same as the
conventional result.
