aspg-21-4126-1791472388 20261008151308 American Scientific Publishing Group admin@americaspg.com American Scientific Publishing Group International Journal of Neutrosophic Science IJNS 2692-6148 2690-6805 2026 27 1 Nur Athirah Hani Senin Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, Cawangan Melaka, Kampus Bandaraya Melaka, 75350 Melaka, Malaysia Yuzaimi Yunus Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, Cawangan Melaka, Kampus Jasin, 77300 Melaka, Malaysia Nur Hazwani Aqilah Abdul Wahid Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia Rashidah Omar Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, Cawangan Sabah, 88450 Kota Kinabalu, Malaysia This paper introduces the class Mε,4L, defined through a convex combination of starlike and convex functions associated with a four-cusped epicycloid domain, where the parameter satisfies 0 ≤ ε ≤ 1. Unlike earlier studies that focused on circular or conic domains, this work extends the geometric framework to epicycloidal domains. Within this framework, sharp estimates for the first coefficients are obtained, together with the Fekete-Szeg¨o inequality and the second Hankel determinant evaluations. These findings extend several classical results for starlike and convex functions and offer new perspectives on analytic function theory related to epicycloidal domains. 2026 234 245 4126 https://creativecommons.org/licenses/by/4.0/ 10.54216/IJNS.270121 https://www.americaspg.com/journal/21/article/4126 https://www.americaspg.com/storage/01758660475.pdf