Khalil Ullah

Dr. Khalil Ullah

Abdul Wali Khan University Mardan, Mardan, Khyber Pakhtunkhwa, Pakistan

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 November 2022 in Fractal and Fractional
Verified
Journal Article
Open access
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LSLei Shi
Lei Shi
Muhammad ArifMuhammad Arif
Muhammad Arif
JIJaved Iqbal
Javed Iqbal
KUKhalil Ullah
Khalil Ullah
SGSyed Muhammad Ghufran
Syed Muhammad Ghufran
Using the Lebedev–Milin inequalities, bounds on the logarithmic coefficients of an analytic function can be transferred to estimates on coefficients of the function itself and related functions. From this fact, the study of logarithmic-related problems of a certain subclass of univalent functions has attracted much attention in recent years. In our present investigation, a subclass of starlike functions Se* connected with the exponential mapping was considered. The main purpose of this article is to obtain the sharp estimates of the second Hankel determinant with the logarithmic coefficient as entry for this class.

1 January 2024 in Applicable Analysis and Discrete Mathematics
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Journal Article
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ZWZhi-Gang Wang
Zhi-Gang Wang
Hari Mohan SrivastavaHari Mohan Srivastava
Hari Mohan Srivastava
Muhammad ArifMuhammad Arif
Muhammad Arif
ZLZhi-Hong Liu
Zhi-Hong Liu
KUKhalil Ullah
Khalil Ullah
In this paper, we determine the sharp upper bounds of Hankel determinants for logarithmic and inverse functions of bounded turning functions associated with the hyperbolic tangent function.

11 August 2022 in Fractal and Fractional
Verified
Journal Article
Open access
PDF file
LSLei Shi
Lei Shi
Muhammad ArifMuhammad Arif
Muhammad Arif
KUKhalil Ullah
Khalil Ullah
NANasser Alreshidi
Nasser Alreshidi
MSMeshal Shutaywi
Meshal Shutaywi
In our present investigation, a subclass of starlike function Sn−1,L* connected with a domain bounded by an epicycloid with n−1 cusps was considered. The main work is to investigate some coefficient inequalities, and second and third Hankel determinants for functions belonging to this class. In particular, we calculate the sharp bounds of the third Hankel determinant for f∈S4L* with zf′(z)f(z) bounded by a four-leaf shaped domain under the unit disk D.