{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T11:01:00Z","timestamp":1770980460292,"version":"3.50.1"},"reference-count":31,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2022,3,24]],"date-time":"2022-03-24T00:00:00Z","timestamp":1648080000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Axioms"],"abstract":"<jats:p>The present paper introduces a new class of bi-univalent functions defined on a symmetric domain using Gegenbauer polynomials. For functions in this class, we have derived the estimates of the Taylor\u2013Maclaurin coefficients, a2 and a3, and the Fekete-Szeg\u00f6 functional. Several new results follow upon specializing the parameters involved in our main results.<\/jats:p>","DOI":"10.3390\/axioms11040147","type":"journal-article","created":{"date-parts":[[2022,3,25]],"date-time":"2022-03-25T00:05:18Z","timestamp":1648166718000},"page":"147","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Coefficient Estimates and Fekete\u2013Szeg\u00f6 Functional Inequalities for a Certain Subclass of Analytic and Bi-Univalent Functions"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5891-4249","authenticated-orcid":false,"given":"Mohamed","family":"Illafe","sequence":"first","affiliation":[{"name":"School of Mathematical Sciences, Universiti Sains Malaysia, Gelugor 11800, Malaysia"},{"name":"School of Engineering, Math & Technology, Navajo Technical University, Crownpoint, NM 87313, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ala","family":"Amourah","sequence":"additional","affiliation":[{"name":"Department of Mathematics, Faculty of Science and Technology, Irbid National University, Irbid 21110, Jordan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maisarah","family":"Haji Mohd","sequence":"additional","affiliation":[{"name":"School of Mathematical Sciences, Universiti Sains Malaysia, Gelugor 11800, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1090\/S0002-9939-1967-0206255-1","article-title":"On a Coefficient Problem for Bi-Univalent Functions","volume":"18","author":"Lewin","year":"1967","journal-title":"Proc. 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