Sharp bound for the second Hankel determinant for a $q$-starlike function associated with the $q$-exponential function

UDC 517.5 We determine the sharp bound of the second-order Hankel determinant $H_{2,2}(f)$ and the coefficient functional for functions from the class of $q$-starlike functions  $ \mathcal{S}^*(\mathcal{L},q)$ by refining the results obtained in [Srivastava et al., Upper bound of the third Hankel de...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Datum:2026
1. Verfasser: Kumar, Karri Sanjay
Format: Artikel
Sprache:Englisch
Veröffentlicht: Institute of Mathematics, NAS of Ukraine 2026
Online Zugang:https://umj.imath.kiev.ua/index.php/umj/article/view/9106
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Назва журналу:Ukrains’kyi Matematychnyi Zhurnal
Завантажити файл: Pdf

Institution

Ukrains’kyi Matematychnyi Zhurnal
_version_ 1860513381306335232
author Kumar, Karri Sanjay
Kumar, Karri Sanjay
author_facet Kumar, Karri Sanjay
Kumar, Karri Sanjay
author_sort Kumar, Karri Sanjay
baseUrl_str https://umj.imath.kiev.ua/index.php/umj/oai
collection OJS
datestamp_date 2026-03-21T13:36:21Z
description UDC 517.5 We determine the sharp bound of the second-order Hankel determinant $H_{2,2}(f)$ and the coefficient functional for functions from the class of $q$-starlike functions  $ \mathcal{S}^*(\mathcal{L},q)$ by refining the results obtained in [Srivastava et al., Upper bound of the third Hankel determinant for a subclass of $q$-starlike functions associated with the $q$-exponential function, Bull.  Sci. Math., 167 (2021); https://doi.org/10.1016/j.bulsci.2020.102942].  Moreover, we  obtain sharp estimates for the Fekete–Szegö functional and the coefficient differences for the analyzed class of functions.
doi_str_mv 10.3842/umzh.v77i12.9106
first_indexed 2026-03-24T03:43:46Z
format Article
fulltext
id umjimathkievua-article-9106
institution Ukrains’kyi Matematychnyi Zhurnal
keywords_txt_mv keywords
language English
last_indexed 2026-03-24T03:43:46Z
publishDate 2026
publisher Institute of Mathematics, NAS of Ukraine
record_format ojs
resource_txt_mv
spelling umjimathkievua-article-91062026-03-21T13:36:21Z Sharp bound for the second Hankel determinant for a $q$-starlike function associated with the $q$-exponential function Sharp bound for the second Hankel determinant for a $q$-starlike function associated with the $q$-exponential function Kumar, Karri Sanjay Kumar, Karri Sanjay Analytic functions q-derivative Hankel determinant q starlike functions q-exponential function. 30C45 30C50 UDC 517.5 We determine the sharp bound of the second-order Hankel determinant $H_{2,2}(f)$ and the coefficient functional for functions from the class of $q$-starlike functions  $ \mathcal{S}^*(\mathcal{L},q)$ by refining the results obtained in [Srivastava et al., Upper bound of the third Hankel determinant for a subclass of $q$-starlike functions associated with the $q$-exponential function, Bull.  Sci. Math., 167 (2021); https://doi.org/10.1016/j.bulsci.2020.102942].  Moreover, we  obtain sharp estimates for the Fekete–Szegö functional and the coefficient differences for the analyzed class of functions. УДК 517.5 Точна межа для другого визначника Ганкеля для $q$-зіркоподібної функції, пов'язаної з $q$-експоненціальною функцією Досліджено точну межу  визначника Ганкеля $H_{2,2}(f)$ другого порядку та коефіцієнтного функціонала для функцій, що належать до класу $q$-зіркоподібних функцій $\mathcal{S}^*(\mathcal{L},q)$. Ці результати отримано шляхом уточнення теорем, наведених у праці Шрівастави та ін. [Upper bound of the third Hankel determinant for a subclass of $q$-starlike functions associated with the $q$-exponential function, Bull. Sci. Math., 167 (2021); https://doi.org/10.1016/j.bulsci.2020.102942]. Також отримано точні оцінки для функціонала Фекете–Сеге та різниць коефіцієнтів у визначеному класі функцій. Institute of Mathematics, NAS of Ukraine 2026-03-21 Article Article https://umj.imath.kiev.ua/index.php/umj/article/view/9106 10.3842/umzh.v77i12.9106 Ukrains’kyi Matematychnyi Zhurnal; Vol. 77 No. 12 (2025); 745 Український математичний журнал; Том 77 № 12 (2025); 745 1027-3190 en https://umj.imath.kiev.ua/index.php/umj/article/view/9106/10610 Copyright (c) 2025 Karri Sanjay Kumar
spellingShingle Kumar, Karri Sanjay
Kumar, Karri Sanjay
Sharp bound for the second Hankel determinant for a $q$-starlike function associated with the $q$-exponential function
title Sharp bound for the second Hankel determinant for a $q$-starlike function associated with the $q$-exponential function
title_alt Sharp bound for the second Hankel determinant for a $q$-starlike function associated with the $q$-exponential function
title_full Sharp bound for the second Hankel determinant for a $q$-starlike function associated with the $q$-exponential function
title_fullStr Sharp bound for the second Hankel determinant for a $q$-starlike function associated with the $q$-exponential function
title_full_unstemmed Sharp bound for the second Hankel determinant for a $q$-starlike function associated with the $q$-exponential function
title_short Sharp bound for the second Hankel determinant for a $q$-starlike function associated with the $q$-exponential function
title_sort sharp bound for the second hankel determinant for a $q$-starlike function associated with the $q$-exponential function
topic_facet Analytic functions
q-derivative
Hankel determinant
q starlike functions
q-exponential function.
30C45
30C50
url https://umj.imath.kiev.ua/index.php/umj/article/view/9106
work_keys_str_mv AT kumarkarrisanjay sharpboundforthesecondhankeldeterminantforaqstarlikefunctionassociatedwiththeqexponentialfunction
AT kumarkarrisanjay sharpboundforthesecondhankeldeterminantforaqstarlikefunctionassociatedwiththeqexponentialfunction