Usman Riaz

Dr. Usman Riaz


Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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1 January 2019 in Mathematical Problems in Engineering
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Journal Article
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URUsman Riaz
Usman Riaz
AZAkber Zada
Akber Zada
Zeeshan AliZeeshan Ali
Zeeshan Ali
MAManzoor Ahmad
Manzoor Ahmad
Jiafa XuJiafa Xu
Jiafa Xu
ZFZhengqing Fu
Zhengqing Fu
This work is committed to establishing the assumptions essential for at least one and unique solution of a switched coupled system of impulsive fractional differential equations having derivative of Hadamard type. Using Krasnoselskii’s fixed point theorem, the existence, as well as uniqueness results, is obtained. Along with this, different kinds of Hyers–Ulam stability are discussed. For supporting the theory, example is provided.

26 October 2018 in Bollettino dell'Unione Matematica Italiana
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Journal Article
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AZAkbar Zada
Akbar Zada
URUsman Riaz
Usman Riaz
FKFarhan Ullah Khan
Farhan Ullah Khan

11 June 2019 in Advances in Difference Equations
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Journal Article
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URUsman Riaz
Usman Riaz
AZAkbar Zada
Akbar Zada
Zeeshan AliZeeshan Ali
Zeeshan Ali
Yujun CuiYujun Cui
Yujun Cui
JXJiafa Xu
Jiafa Xu
We present some results on the existence, uniqueness and Hyers–Ulam stability to the solution of an implicit coupled system of impulsive fractional differential equations having Hadamard type fractional derivative. Using a fixed point theorem of Kransnoselskii’s type, the existence and uniqueness results are obtained. Along these lines, different kinds of Hyers–Ulam stability are discussed. An example is given to illustrate the main theorems.

24 December 2022 in Fractal and Fractional
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LGLimin Guo
Limin Guo
URUsman Riaz
Usman Riaz
AZAkber Zada
Akber Zada
MAMehboob Alam
Mehboob Alam
This study is devoted to studying the existence and uniqueness of solutions for Hadamard implicit fractional differential equations with generalized Hadamard fractional integro-differential boundary conditions by utilizing the contraction principle of the Banach and Leray–Schauder fixed point theorems. Moreover, with two different approaches, the Hyers–Ulam stabilities are also discussed. Different ordinary differential equations of the third order with different boundary conditions (e.g., initial, anti periodic and integro-differential) can be obtained as a special case for our proposed model. Finally, for verification, an example is presented, and some graphs for the particular variables and particular functions are drawn using MATLAB.

12 November 2020 in International Journal of Nonlinear Sciences and Numerical Simulation
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Journal Article
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URUsman Riaz
Usman Riaz
AZAkber Zada
Akber Zada
This article is devoted to establish the existence of solution of (α,β)-order coupled implicit fractional differential equation with initial conditions, using Laplace transform method. The topological degree theory is used to obtain sufficient conditions for uniqueness and at least one solution of the considered system. Beside this, Ulam’s type stabilities are discussed for the proposed system. To support our main results, we present an example.

10 March 2024 in Qualitative Theory of Dynamical Systems
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YMYanli Ma
Yanli Ma
MMMaryam Maryam
Maryam Maryam
URUsman Riaz
Usman Riaz
Popa Ioan-LucianPopa Ioan-Lucian
Popa Ioan-Lucian
LRLakhdar Ragoub
Lakhdar Ragoub
AZAkber Zada
Akber Zada