It is necessary to replace the expression in formula (22) and the one just after (appearing in Pramana – J. Phys. 91, 76 (2018)):

$$\begin{aligned} P\left( y_{1},y_{2} \right)= & {} \left| \mathrm {\psi }\left( y_{1},y_{2},t_{0}+\tau \right) \right| ^{2\, }\nonumber \\= & {} P_{1}\left( y_{1},y_{2} \right) +P_{2}\left( y_{1},y_{2} \right) +{2P}_{3}\left( y_{1},y_{2} \right) \nonumber \\&\cdot \left[ \left| \alpha \right| ^{2}\mathrm {cos}\left( \theta _{1}y_{1}+\theta _{2}y_{2}\mathrm {+\Phi } \right) \nonumber \right. \\&\left. +\left| \beta \right| ^{2}\mathrm {cos}\left( \theta _{1}y_{1}+\theta _{2}y_{2}-\Phi \right) \right] ,\\ P\left( y_{1},y_{2} \right)= & {} P_{1}\left( y_{1},y_{2} \right) +P_{2}\left( y_{1},y_{2} \right) +{2P}_{3}\left( y_{1},y_{2} \right) \nonumber \\&\quad \cdot \sqrt{\cos ^{2}\Phi +\cos ^{2}\delta \sin ^{2}\Phi } \cos ( \lambda -\Phi )\nonumber \end{aligned}$$
(22)

by

$$\begin{aligned} P\left( y_{1},y_{2} \right)= & {} \left| {\psi }\left( y_{1},y_{2},t_{0}+\tau \right) \right| ^{2\, }\nonumber \\ P\left( y_{1},y_{2} \right)= & {} P_{1}\left( y_{1},y_{2} \right) +P_{2}\left( y_{1},y_{2} \right) +P_{3}\left( y_{1},y_{2} \right) \nonumber \\&\quad \cdot 2\mathrm {cos}\left( \theta _{1}y_{1}+\theta _{2}y_{2}-2\pi \frac{{\Phi }}{{\Phi }_{0}} \right) . \end{aligned}$$
(22)