Stable four-dimensional solitons in graded-index materials with Kerr nonlinearity

In the present paper, by using a variational approach, we have investigated the propagation of 4D optical pulses through graded index materials with Kerr nonlinearity. We find that stable 4D solitons can exist as long as the dispersion is negative and as long as the pulse energy is less than a critical energy. A GRIN material is a material with a parabolic refractive index.<
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