@article{article_812878, title={Index and Equality Conditions of the Subgroups $\Gamma_{0,n}(N)$ and $\Lambda_n(N)$}, journal={Konuralp Journal of Mathematics}, volume={9}, pages={60–64}, year={2021}, author={Büyükkaragöz, Aziz and Ünlüyol, Erdal and Akbaş, Mehmet}, keywords={Congruence subgroup of modular group, transitivity, conjugateness, stabilizing, infinite cycle group, index formula}, abstract={<div style="text-align:justify;"> <span style="font-size:14px;">In this paper, we find conditions on the natural number $n$ that the subgroups $\Gamma_{0,n}(N)$ and $\Lambda_n(N)$ of modular group are different. And then, by defining an $\Lambda_n(N)$ invariant equivalence relation on the subset $\hat{\mathbb{Q }_n(N)$, we calculate the index formula for $\Gamma_{0,n}(N)$ in $\Lambda_n(N)$. </span> </div>}, number={1}, publisher={Mehmet Zeki SARIKAYA}