We are excited to invite you to delve into the most highly cited papers from our journal Mathematics (ISSN: 2227-7390) for the year 2022. These papers, carefully selected for their exceptional quality and relevance, represent cutting-edge research in various branches of mathematics and applied mathematics.

1. “On Numerical Approximations of the Koopman Operator”
by Igor Mezić
Mathematics 2022, 10(7), 1180; https://doi.org/10.3390/math10071180
Full text available online: https://www.mdpi.com/2227-7390/10/7/1180

2. “Bifurcation Theory, Lie Group-Invariant Solutions of Subalgebras and Conservation Laws of a Generalized (2+1)-Dimensional BK Equation Type II in Plasma Physics and Fluid Mechanics”
by Oke Davies Adeyemo, Lijun Zhang and Chaudry Masood Khalique
Mathematics 2022, 10(14), 2391; https://doi.org/10.3390/math10142391
Full text available online: https://www.mdpi.com/2227-7390/10/14/2391

3. “Bio-Constrained Codes with Neural Network for Density-Based DNA Data Storage”
by Abdur Rasool, Qiang Qu, Yang Wang and Qingshan Jiang
Mathematics 2022, 10(5), 845; https://doi.org/10.3390/math10050845
Full text available online: https://www.mdpi.com/2227-7390/10/5/845

4. “How Many Fractional Derivatives Are There?”
by Duarte Valério, Manuel D. Ortigueira and António M. Lopes
Mathematics 2022, 10(5), 737; https://doi.org/10.3390/math10050737
Full text available online: https://www.mdpi.com/2227-7390/10/5/737

5. “Mathematical Modeling and Analytical Solution of Thermoelastic Stability Problem of Functionally Graded Nanocomposite Cylinders within Different Theories”
by Mahmure Avey, Nicholas Fantuzzi and Abdullah Sofiyev
Mathematics 2022, 10(7), 1081; https://doi.org/10.3390/math10071081
Full text available online: https://www.mdpi.com/2227-7390/10/7/1081

6. “The Interplay between Digital Entrepreneurship and Sustainable Development in the Context of the EU Digital Economy: A Multivariate Analysis”
by Emilia Herman
Mathematics 2022, 10(10), 1682; https://doi.org/10.3390/math10101682
Full text available online: https://www.mdpi.com/2227-7390/10/10/1682

7. “A System with Two Spare Units, Two Repair Facilities, and Two Types of Repairers”
by Vahid Andalib and Jyotirmoy Sarkar
Mathematics 2022, 10(6), 852; https://doi.org/10.3390/math10060852
Full text available online: https://www.mdpi.com/2227-7390/10/6/852

8. “Riemann–Hilbert Problems and Soliton Solutions of Type (λ∗, −λ∗) Reduced Nonlocal Integrable mKdV Hierarchies”
by Wen-Xiu Ma
Mathematics 2022, 10(6), 870; https://doi.org/10.3390/math10060870
Full text available online: https://www.mdpi.com/2227-7390/10/6/870